Maximum Yield UK Nov/Dec 2011 by Maximum Yield

UK November - December 2011

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Biology VS Technology Mother Nature Meet Modern Mechanics

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Microbes Rock

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Maximum Yield UK | November/ December 2011

CONTENTS November/December 2011

FEATURES 20

I Love the Smell of H20 in the Morning by Dr. Lynette Morgan

54 35

TDS Metres, Conductivity and Conversion Factors by Rob Samborn

The ABCs of Hydroponics

Vitamin P: Plasma Lamp Technology

50 51 54

Plants Gone Wild

Biology Versus Technology

by Andew Taylor

by Dr. J. Benton Jones, Jr.

56 DEPARTMENTS

by Philip McIntosh

From the Editor

You Tell Us

Gift Ideas for Gardeners

MaximumYield.com

Industry’s Latest

Letters to the Editor

Talking Shop

Simon Says

Do You Know?

by Matt LeBannister

MAX Facts

10 Reasons Beneficial Soil Microbes Rock

Coming up in Jan/Feb

Product Spotlight

Max Mart

by Glory Lennon

Nutrient Deficiencies: Reaction and Prevention Part One

by Brian Mack

Automation Nation

Massive Attack

by Isabelle Lemay, agr. and Mélissa Léveillé by Therese Cressman

Maximum Yield UK | November / December 2011

FROM THE EDITOR | Jessica Raymond

You asked for it and we have it for you right here in Maximum Yield UK’s biggest issue ever! Your favourite resource for indoor gardening is now fatter with more of what you want—new and innovative products, global industry news and trivia, contests, grow tips and expert garden advice. This issue brings you the latest on proper climate calibration, nutrient deficiency prevention, benefits of plasma grow lights and more. As you flip through you will notice even more to get excited about. We’ve added a new column, Industry’s Latest, which is filled with exciting deals, upcoming events,

news and giveaways exclusively available to our UK readers. We have some fantastic issues planned for 2012 to help you grow your best. Got questions or article requests? Simply drop us an e-mail at editor@maximumyield.com and we will make sure to get you the answers. Thank you for your tremendous feedback and support. Now sit back and enjoy this fat issue of Maximum Yield UK! PS. Make sure to flip to page 61 to check out the latest prizes up for grabs in our Win Big…Grow Big online reader contest. Enter online at http://maximumyield.com/winbigUK.php

Jessica Raymond, Editor editor@maximumyield.com

contributors Dr. Lynette Morgan holds a B. Hort.

Philip McIntosh is a science and

Tech. degree and a PhD in hydroponic greenhouse production from Massey University, New Zealand. Lynette is a partner with SUNTEC International Hydroponic Consultants and has authored five hydroponic technical books. Visit www.suntec.co.nz/ consultants.htm and www.suntec. co.nz/books.htm for more information.

technology writer with a bachelor’s degree in botany and chemistry and a master’s degree in biological science. During his graduate research he used hydroponic techniques to grow axenic plants. He lives in Colorado Springs, CO. where he teaches mathematics at Challenger Middle School.

Matt LeBannister developed a

Dr. J. Benton Jones Jr. has 50

Andrew Taylor is the manager of

Rob Samborn is the director of

green thumb as a child, having been born into a family of experienced gardeners. During his career, he has managed a hydroponic retail store and represented leading companies at the Indoor Gardening Expos. Matt has been writing articles for Maximum Yield since 2007. His articles are published around the world.

Flairform (www.flairform.com) – an Australian-based manufacturing company. As an analytical chemist with qualifications in plant function and nutrition, he has over 13 years experience in product research and development, and also writes extensively on hydroponic growing techniques.

Glory Lennon’s four acre lot

includes an arboretum, a thriving koy pond with water lilies, two greenhouses and an orchard. She writes a garden column for a local paper and contributes to several on-line gardening websites and now Maximum Yield. Visit www.helium. com, www.greenthumbarticles.com and www.myspace.com/glorygarden

Maximum Yield UK | November/ December 2011

years of experience growing plants hydroponically. He is an Emeritus Professor at the University of Georgia, Athens and has authored eight books and written articles for magazines that deal with hydroponic issues. He currently has his own consulting company, Grosystems, Inc. Dr. Jones currently lives in Anderson, SC, USA.

sales and marketing for HM Digital, a manufacturer of water testing instruments, including handheld testers, inline monitors and controllers for TDS, EC, pH, ORP, temperature and volume. He can be reached at rob@hmdigital.com

Mélissa Léveillé holds a license

in communication, writing and multimedia. She is the newest member of the Nova Biomatique Inc. Team (www.igrowing.com), makers of the PLUG’N’GROW climate controllers. She is responsible for Nova Biomatique Inc.’s communications.

Brian Mack is a website designer and marketer from Salinas, CA. In his spare time, he hikes and spends his afternoon gardening. He is a firm believer in good soil biology, and encourages soil biology in his garden by using mycorrhizae and azospirillum.

Isabelle Lemay is in charge of the

technical support, customer service and research and development at Nova Biomatique Inc. (www.igrowing. com), makers of the PLUG’N’GROW climate controllers. She is an agronomist and holds a master’s degree in soil and environment studies, with a specialization in greenhouse production.

Become a Maximum Yield contributor and have your articles read by 250,000 readers throughout USA, Canada, UK, New Zealand and Australia. Maximum Yield is the largest free-to-consumer indoor gardening magazine in the world. Every issue is available on maximumyield.com, which has thousands of unique visitors monthly.

Maximum Yield UK | November / December 2011

Coming up on the Web Upcoming Events

2012 Indoor Gardening Expo Tour The dates are set, the venues are chosen and the 2012 Indoor Gardening Expo Tour is coming to four North American cities next year. You’re invited to visit one, two, three or all four shows. Stay tuned to indoorgardenexpo.com for details so you can plan your 2012 vacation.

Latest News Rooftop farms are sprouting up all over the globe and changing how people think of gardening. There’s probably one near you. Check them out on maximumyield.com under Latest News.

Got Questions? Get Answers.

VOLUME 11 – NUMBER 4 November/December 2011 Maximum Yield is published bi-monthly by Maximum Yield Publications Inc. 2339A Delinea Place, Nanaimo, BC V9T 5L9 Phone: 250.729.2677; Fax 250.729.2687 No part of this magazine may be reproduced without permission from the publisher. If undeliverable please return to the address above. The views expressed by columnists are a personal opinion and do not necessarily reflect those of Maximum Yield or the Editor. Publication Agreement Number 40739092

PRESIDENT/PUBLISHER - Jim Jesson GENERAL MANAGER - Don Moores BUSINESS MANAGER - Linda Jesson EDITOR - Jessica Raymond jessica@maximumyield.com ADVERTISING SALES 250.729.2677 Linda Jesson - linda@maximumyield.com Lisa Lambersek - lisa@maximumyield.com Ilona Hawser - ilona@maximumyield.com Hayley Jesson- hayley@maximumyield.com Ashley Heppell - ashley@maximumyield.com PRODUCTION & DESIGN ads@ads.maximumyield.com Mike Linden - mike@maximumyield.com Jenn Duong - jennifer@maximumyield.com Tina Skujins - tina@maximumyield.com Alice Joe - alice@maximumyield.com ACCOUNTING - Tracy Greeno accounting@maximumyield.com

Maximum Yield’s resident experts are available and ready to answer your modern gardening questions. E-mail editor@maximumyield.com or fill out the Ask the Experts question form on maximumyield.com

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Maximum Yield UK | November/ December 2011

UK DISTRIBUTION Growth Technology Future Harvest Developments Europe Nutriculture UK Direct Garden Supplies CANADIAN DISTRIBUTION Brite-Lite Group Biofloral Eddis Wholesale Greenstar Plant Products Inc. Hydrotek MegaWatt Northern Hydroponic Wholesale Quality Wholesale USA DISTRIBUTION Aurora Innovations BWGS General Hydroponics Humboldt Wholesale Hydrofarm Hydro International National Garden Wholesale / Sunlight Supply Nickel City Wholesale Garden Supply R & M Supply Tradewinds AUSTRALIAN DISTRIBUTION Dome Garden Supply Futchatec Growth Technology Holland Forge House N Garden Hydraspher

Maximum Yield UK | November / December 2011

LETTERS TO THE EDITOR Homegrown Hydroponics

Ammonia for Plants – Dangerous or Beneficial?

Thanks to Maximum Yield and its contributors for the helpful information and great articles. I am new to hydroponics and gardening all together and I believe I have found a new passion and lifestyle to enjoy! Over the summer I harvested a variety of tomatoes. I’m looking forward to my jalapenos and anything else I may grow. The goal now is to never have to buy veggies. Thanks again Angel Bueno

I love your magazine and online information, but cannot locate a search box, so I will just ask. I thought I read an article in your magazine regarding using ammonia in the garden. Do you recall what ammonia is used for? I bought four litres of it, and cannot decide what to do with it. I don’t want to destroy my greenhouse plants. I put a little ammonia in a spray bottle, and lightly sprayed the dirt on two planters in the greenhouse, hoping any spiders would scram; and they did. I have been keeping an eye on those plants and so far they show no ill effects, except for one low leaf is turning yellow, which I removed. Thank you for replying to my little inquiry. I appreciate it. Angel with his hybrid DWC tomato

Run, Don’t Walk, to Your Nearest Hydroponic Shop

Thank you for such a well thought out and put together magazine. You guys and gals are doing a great job and yours is the only magazine I read from cover to cover each month. When I can get a hold of a hard copy, I keep it for reference. I have been growing hydroponically for 25 years indoors and am thinking about doing some growing outdoors next year in hydro. Thanks again for all your hard work; it sure shows every month when I get to read the next issue. Thanks Bob Albright

Thanks Sharon Calabrese Ammonia does have a place in the garden. Ammonia can be diluted and used as a fertilizer. A quarter cup of ammonia per four litres of water can be mixed, and the plants can be sprayed with this solution once per week. When ammonia breaks down it releases nitrates, a source of nitrogen. This should only be used on alkalineloving plants such as sweet peas and asparagus because ammonia is very alkaline. It will actually damage acid-loving plants such as tomatoes. Many types of ammonia contain other ingredients intended only for cleaning and will not be safe for your plants. A safer alternative to using ammonia would be to use pine tree oil or kelp spray. These products can be applied safely to a wide range of plants. Ammonia can also be used to battle mildew growing on soil or on the plant itself. Use the same concentration mentioned earlier and apply to the surface of the soil or on the leaves once per week until the mildew is gone. Ammonia is also often used to detour large pests from eating your crops. Outdoors it can be used to prevent raccoons, rabbits, skunks and other animals from getting at your crops. Indoors it can be used to keep your household pets, such as cats or dogs, from getting into your garden. For this purpose the plants do not need to be in direct contact with the ammonia, but it can be sprayed around the general garden area. The idea is that the ammonia will mimic the urine of predatory animals thus keeping the animals that will eat your plants at bay. Ammonia is a harsh chemical with powerful fumes that should not be inhaled. The mixing of ammonia should only be done outside or in a well ventilated room and should only be mixed with water and no other chemicals. If ammonia is mixed with bleach you would essentially make mustard gas, which is highly toxic when inhaled and can be lethal. Thanks for the inquiry, Sharon. Hope this answers your question. Matt LeBannister

We want to hear from you! Write us at: Maximum Yield Publications Inc. 2339 Delinea Place, Nanaimo, BC V9T 5L9 or e-mail us at: editor@maximumyield.com 10

Maximum Yield UK | November/ December 2011

SIMON says

I have some yellowing leaves, both on the fringe and in a couple of cases the whole leaf. Two of the leaves look like yellow paint was spilled on them. Can you suggest possible causes? Thanks, Charlie

Ahhh, the murky world of nutrient deficiency diagnosis! This issue can be a bane to rookie and veteran gardeners alike. Many people are far too cavalier about this issue and their solutions end up causing more problems either through misdiagnosis or over correction. First off check the solution pH in a water system or test the leachate in a soilless system. There is no point in trying to mitigate a nutrient problem if your plants’ roots are in a situation where they can’t access the right mineral balance. With all plant issues you must visually assess the situation and track the movement of the issue on the plant structures themselves.Your question doesn’t specify enough to truly diagnose the issue, which is already difficult to solve without visual assessment of the plant in question. However, I will detail three of the most common deficiencies that could be causing the problem you are describing. Before commenting on the three most likely causes of the problem, I would like to remind all readers that whenever possible, if you determine it’s worth the cost, sending away a dried tissue sample to a lab for analysis is a great way to check the nutrient balance within your plant. In fact this could be useful even for healthy plants so you have a baseline of nutrient ratios that you can specifically target in successive crops. For now let’s try and troubleshoot. Remember that taking the time to properly diagnosis a crop problem will benefit you in the future because you will be able to identify and address the issue rapidly, keeping your garden growing in the right direction. One of the most common causes of yellowing leaves in gardens is a nitrogen (N) problem. When deficient, nitrogen will cause new growth to be very small and plants will grow slowly. In cases of serious deficiency nitrogen will cause yellowing of leaves. In the case of nitrogen, which is mobile within the plant, you will see yellowing on the older, lower leaves first as nitrogen is shifted to developing growth. Check with your local grow shop or nutrient manufacturer for a product suggestion and for an application rate. Spot treat a plant with a nitrogen foliar 12

Maximum Yield UK | November/ December 2011

spray (nitrate nitrogen if possible) and assess the effect. A spot treatment is a technique of testing a product on a small part of your garden prior to applying it to all plants. If you are unsure of the problem you can try different spot treatments at the same time to try and isolate the issue. Another possible culprit is a lack of magnesium (Mg). Again this issue will generally start in lower leaves but will be more pronounced initially in the leaf margin and along the edges of the lobes. Eventually the leaves will turn completely yellow with the exception of the venation. Remember that it starts from the older leaves because magnesium is not entirely mobile. This is distinct from the third possibility. Epsom salts (MgSO4) are a good idea for a root application or foliar spray. Check with your local grow shop or nutrient manufacturer for a product suggestion and an application rate and then spot treat a plant to assess the effect. Iron (Fe) deficiency also causes yellowing in leaves and can be a common issue as well. Because iron is not incredibly mobile the deficiency will occur in the newer leaves rather than the older leaves as compared to a magnesium deficiency. It will also start in the leaf margins working its way to the middle while leaving the venation green. Chelated iron is available in many products and is absorbable as a foliar spray. Again, check with your local shop or nutrient manufacturer for a product suggestion and an application rate and then spot treat a plant to assess the effect. It is possible to find some products in the market that combine useful options for all three issues in one bottle. Check with you local hydroponic retailer and ask about their calcium supplement options. In general these products will contain nitrate nitrogen, magnesium and chelated iron within their formula. I can’t emphasize enough what an excellent resource your local grow shop can be. Whenever you have nutrient issues be sure to consult their knowledgeable staff. Good luck in the garden.

Maximum Yield UK | November / December 2011

MAX FACTS

hydroponic news, tips and trivia

E. coli an Unlikely Contaminant of Plant Vascular Systems

MAXFACTS hydroponic news, tips and trivia

Scientists have helped confirm that Escherichia coli is not likely to contaminate the internal vascular structure of field-grown leafy greens. There was no evidence that E. coli had become “internalised” in leaves or shoots of baby spinach plants 28 days after the plants had germinated and grown in pasteurized soil. (Source: www.ars.usda.gov)

Testing Fumigant Films That Keep the Air Clean

Researchers have found a way to help growers minimise emissions of fumigants used as soil treatments, as part of a special project to find the best alternatives to methyl bromide—which is being phased out as a fumigant because of its harmful effects on the Earth’s protective ozone layer. (Source: www.ars.usda.gov)

Boosting the Pineapple Industry in the Bahamas Bahamas Agricultural and Industrial Corporation (BAIC) has started distribution of 5,000 tissue cultured sweet cayenne pineapple slips throughout the islands in an effort to stimulate the Bahamian pineapple industry. The slips were imported and hardened at Nassau’s Lucayan Tropical hydroponics farm. Presently, sweet cayenne pineapples are imported from Costa Rica and sold in the food stores. By producing them locally, there would be no need to import them. BAIC’s next initiative is the distribution of fruit trees—avocado, mango, soursop, guava and Persian lime (Sources: bahamaislandsinfo.com, www.freshplaza.com)

Versatile Compound Examined in Crops

Scientists are “spiking” laboratory diets fed to corn earworms and fall armyworms with saponins from soybeans, switchgrass, yerba mate and other sources to determine their effectiveness in protecting plants from insect attacks. (Source: www.ars.usda.gov) 14

Maximum Yield UK | November/ December 2011

India Takes Monsanto to Court Agri-giants Monsanto, developers of India’s first genetically modified food crop—a variety of eggplant known as Bt brinjal—are being accused of biopiracy (biological theft) by the National Biodiversity Authority (NBA) of India. NBA says the developers of Bt brinjal used local varieties of eggplant in developing the GM crop “without prior approval of the competent authorities.” (GM Watch) (Sources: www.treehugger.com, www.gmwatch.org)

Promising Results From Hydroponically-Cultivated Lettuce The first results of the hydroponic cultivation system put up by Enza Zaden at its improvement hothouse are promising. Enza Zaden’s hydroponic lettuce team researches which varieties are especially suited for cultivation on water. The focus for now is on various types of lettuce—batavia, butter lettuce and Eazyleaf—but the seed company is looking to extend the project to include, endive, herbs and other leafy plants. (Sources: www.enzazaden.com, www.freshplaza.com)

What Counts is the Water That Actually Enters Plant Roots To help farmers make the best use of limited irrigation water in arid landscapes, agriculture researchers are helping farmers determine how much water major crops actually need. Researchers are measuring crop water use efficiency by yield per drop of water actually taken in by the crop. Crops are being grown with six levels of irrigation, from full irrigation down to only 40 per cent of full. These results will help farmers decide whether to put all their irrigation water into producing corn, or to reduce either their irrigation levels or the amount of land they plant, and sell or lease water rights on the rest. (Source: www.ars.usda.gov)

Planting a Rooftop Forest Garden The Reading International Solidarity Centre (RISC) in Reading, Berkshire’s rooftop forest garden was created in 2002 as a means to grow food for its cafe, provide composting facilities, establish a meeting space and offer educational opportunities about food growing. You can find everything from Japanese mountain banana and Musa basjoo, to globe artichokes and Cynara scolymus, and forage for produce as you walk around. Nine years since its creation, RISC is now hosting a day-long event on forest gardening and its role in transforming our food systems. You can learn more about the whole project at www.risc.org.uk (Sources: www.treehugger.com)

Maximum Yield UK | November / December 2011

PRODUCT SPOTLIGHT

YOUR GUIDE TO THIS MONTH’S

HOTTEST ITEMS Ask for them at your local indoor gardening store.

Bloombastic Starter Kit’s Little Brother - Coco Collection For beginners and hobby growers, Atami has developed the Coco Collection Box. It contains all the products necessary for an entire cycle in one box. The Coco Collection Box is suitable for two to three plants on coco. Growing has never been easier. In combination with the ATA nutrients and supplements, the Coco Collection Box provides excellent growth and flowering results. The Coco Collection Box contains: Coco Max A & Coco Max B (250 millilitres), Atazyme & Rootfast (100 millilitres), Bloombastic (60 millilitres) and Atami’s Grow Guide. Visit your favourite indoor gardening shop for more information.

Amino Treatment

Organic Air Charcoal Fibre and HEPA Filters

Unlock the secret to successful growing with Amino Treatment from House & Garden. Using Amino Treatment guarantees abundant growth and explosive flowering of your plants. After many years of research, House & Garden presents this revolutionary growth and flowering booster that contains a well balanced combination of active ingredients. With Amino Treatment your plants will get better foliage distribution, a higher photosynthesis ratio, solid stems, enhanced root activity, increased fruit production and a higher sugar level in the fruit. Distributed in the UK by Direct Garden Supplies and available now at your local hydroponics shop.

Organic Air Charcoal Fibre and HEPA Filters are lightweight, shippable, washable and perfectly suited for any greenhouse. Organic Air Charcoal Fibre Filters consist of high quality charcoal fibre mesh with zillions of micro-pores for optimal adsorption of nasty odours. Our HEPA intake filter keeps grow rooms clean by filtering all moulds, spores, pollens, dirt and insects. The HEPA mesh is five times smaller than a human hair and works at all times with no oiling. Both filters are pleated for a doubling of surface area and use a dual inverted nose cone for maximal air flow. Available now at your local hydro shop.

Not All Contactors Are the Same... Black Box heavy-duty Contactors are made in the UK and assembled according to strict CE standards using only the highest quality components. Key features include professional Grasslin timers, rubberised moulded plugs, handy hanging brackets and switchable sockets (two, four, six and eight socket versions available). For more information, visit your local hydroponics shop.

Maximum Yield UK | November/ December 2011

Cropspray Vitamin Spray for Seedlings, Cuttings and Motherplants Cropspray from Plagron is an innovative vitamin spray that guarantees excellence. Cropspray contains a carefully balanced combination of organic enzymes, trace elements and growth stimulators that protect the plant against negative external influences. Cropspray enables the plant to more easily absorb available nutrients and use them more effectively. Cropspray ensures a comprehensive and strong root system, improved resistance to pests and disease, accelerated absorption of nutrients, faster cell division and more branching and sprouting. Cropspray is highly concentrated so you only need one millilitre per litre of water. Cropspray is available in packs of 100 millilitres, 250 millilitres, 500 millilitres and one litre. For more information visit your local hydroponics shop.

Aero Potz Systems Aero Potz are designed to maximise your crops’ potential. These aeroponics systems allow all your plant roots to be totally suspended in the air and sprayed directly with a nutrient-rich solution from two inverted sprinklers at minute timed intervals. Excess nutrient solution can drain from the Aero Potz through special filters that stop the plant roots from entering and blocking the drain pipes. The excess solution can then run freely into the Header Return Potz, which are fitted with a float switch and pump to recirculate the solution back into the main tank, or if desired it can be run-to-waste into another tank or nearby drain. Visit your favourite indoor gardening shop for more information.

Phat Mufflers Phat Mufflers are made using an all aluminum body and a really phat glasspack that won’t disintegrate like foam over time. The noise reduction coefficient of our glasspack is 85 per cent versus 50 per cent for foam. Phat Mufflers are lightweight, durable and easy to hang, plus they’re available in four to 12 inches with mini sizes too for those tight spaces. Sold exclusively through Hydrogarden UK, Eltac Spain and Dutch Lighting Solutions Holland. Available now at indoor gardening shops across the UK.

Titan Controls® Helios 11™ and Helios 12™ Sunlight Supply®, Inc. is pleased to announce the release of the new Classic Series Helios 11™ and 12™ 240 volt light controllers from Titan Controls®. The Helios 11™ and Helios 12™ feature premium quality Siemens brand relays, trigger cord sets for use with wall timers, multi-tap outlets allow that accept 120 or 240 volt cord sets and plastic enclosures that resist dust and moisture. The Helios 11™ will control up to four 1,000 watt lights at 240 volts and the Helios 12™ will control up to eight 1,000 watt lights at 240 volts. Be in control with Titan. Visit your favourite indoor gardening shop for more information about the Helios 11™ and Helios 12™.

Bloombastic Starter Kit’s Little Brother - Soil Collection For beginners and hobby growers, Atami has developed the Soil Collection Box. It contains all the products necessary for an entire cycle in one box. The Soil Collection Box is suitable for two to three plants on soil. Growing has never been easier. In combination with the ATA nutrients and supplements, the Soil Collection Box provides excellent growth and flowering results. The Soil Collection Box contains: Terra Leaves and Terra Max (250 millilitres), Atazyme (100 millilitres), Bloombastic and Rootfast (60 millilitres) and Atami’s Grow Guide. Visit your favourite local gardening shop for more information.

Maximum Yield UK | November / December 2011

PRODUCT SPOTLIGHT Growlab Grow Tents New to the UK From Nutriculture Developed by Homebox, Growlab tents feature heavy-duty fittings and are designed for big lamps and fans. Coupled with German design efficiency, lightweight build and easy set-up, these are simply some of the best quality grow tents. In a comprehensive range of sizes, every Growlab tent offers: •

Fully sealed, light tight environment

•

Ultra reflective silver interior

•

Heavy-duty cross members will support over 100 pounds

•

Powder coated steel poles are strong yet lightweight

•

Clear viewing windows; no need to unzip to check progress

•

Multiple intake and exhaust ports for air cooled lamps

•

Fully waterproof flooring

Choose Nutriculture for all your Growlab requirements. For more information visit an indoor gardening shop near you.

Gavita Pro 1,000

Phat Filters

The Gavita Pro 1,000 is the first 240 volt electronic ballast that powers the professional Philips GreenPower 1,000 watt 400 volt electronic double ended lamp. This lamp has the highest PAR light output, improved spectrum and the best light maintenance of any horticultural lighting system. It is the only choice for Dutch professional greenhouse growers. The Gavita Pro 1,000 is available as a complete fixture with the highly efficient professional HortiStar HR 96 1,000 DE reflector. Talk to your local retailer for more information about the Gavita Pro 1,000.

Genuine Phat Filters use state-of-the-art design with the best odour absorbing carbon found in the world to give you the best clean-air-producing, greenhouse filter on the market. Phat Filters are made with 1,200 milligrams per gram iodine number, virgin charcoal and a higher grade charcoal than our competitors. Aluminum construction, lightweight charcoal carbon and an anti-air bypass ensure proper filtration. A new internal mesh material eliminates shipping dust plus our new internal packaging ensures safer transport and a conical bottom-air diverter ensures even airflow. Available now at your local hydro shop. Phat is a registered mark of International Growers Supply.

HM Digital Pens and Metres New to the UK Exclusively From Nutriculture Conductivity and pH are two of the most important variables in nutrient management. Keeping nutrient strength correct and consistent will ensure healthy growth and maximum yields. Nutriculture now offers a comprehensive range of metres to suit all budgets. EC Metres include: EC3: The world’s most popular and most reliable TDS metre Ap-2: Advanced design digital water tester COM-100: Combo EC and temperature metre PH Metres include: PH-80: Value pH and temperature metre PH-200: Waterproof pH and temperature metre Choose Nutriculture for these grow room essentials. Visit an indoor gardening shop for more information.

Maximum Yield UK | November/ December 2011

Titan Controls® Atlas 3™, 4™, 5™ and 6™ Sunlight Supply®, Inc. is pleased to announce the release of the newest Atlas CO2 controllers from Titan Controls®. The Titan Controls® C02 control line integrates multiple features, all designed to help take the guesswork out of CO2 monitoring/ controlling in your garden. The Atlas line uses digital technology to monitor/control your garden CO2 levels to help you provide just the right amount of CO2. Be in control with Titan. Visit your local hydro shop for more information.

New Innovation in Hydroponics The Vegigator, developed by IWS and Nutriculture, underwent 12 months of trials and tests and is now available in six, 12 and 24 configurations. It can be used with a variety of pots including IWS (Aqua/Culture) and Smart Pots. All systems were designed to fit into a 1.2 square metre grow room. Vegigator benefits: • Cuttings and seedlings are ready for transplanting into a larger system sooner. • There’s no need for a separate system for the veg phase. • Top trays can be switched to suit the grower’s needs; all systems use the same header tank and delivery system. • Can be used to complete a full grow from start to finish. Distributed in the United Kingdom by Direct Garden Supplies and available at hydroponic shops across the UK.

DWC Potz Systems DWC Potz Systems are active recirculating deep-water-culture systems designed to support your plants in the top of grow pots and allow the roots to be deeply suspended into a nutrient-rich solution. Your nutrient solution can be mixed in the main reservoir and then pumped into the system. The Header Potz are fitted with a pump that is connected to irrigation lines. They lead back into each pot to recirculate the nutrient solution around the system; internal drain filters are fitted to prevent any root growth blocking the pipes and affecting the system’s performance. A pump is also fitted in the Header Potz to allow you to drain the system easily back into the main reservoir or to waste. Visit your favourite indoor gardening shop for more information. Continued on page 66

Maximum Yield UK | November / December 2011

i Love the Smell of H2O in the Morning by Dr. Lynette Morgan

Good quality water is vital for a healthy hydroponic system, but just because what comes out of the tap is clean, clear and good to drink, doesn’t mean your plants will love it as well. Water quality and treatment focuses on making water safe for us, even if that means using disinfectant chemicals to kill human pathogens. Secondary focuses are in treating water so it won’t cause us other hassles such as pipe corrosion, scale formation on appliances, unwanted odours and staining minerals. However, with municipal water treatment no real concern is given to plants or hydroponic systems, so growers are on their own in determining if their water supply is a problem and what to do about it.

Maximum Yield UK | November/ December 2011

There are many options for water treatment and even small growers can use RO, oxygenation and UV treatment systems.

Municipal water supplies Many indoor gardeners are reliant on municipal water supplies and have few other options for a better quality water source. Itâ&#x20AC;&#x2122;s likely that some plant losses have and do occur as a result of some municipal water supplies, particularly in sensitive species and in water culture systems where there is no media to act as a buffer. On the other hand, many municipal water supplies are quite suitable and given that they have had organic matter and pathogens removed already, are a good deal as far as hydroponic systems go. Interestingly plants have rather different responses and requirements from a water sup-

ply than humans and this is where problems can occur. Municipal water treatment ensures that drinking water meets the World Health Organization (WHO) and EPA standards for mineral, chemical and biological contamination levels, making it generally very safe to drink and use. However, what is safe for us to drink may not be so good for plant growth, particularly when we consider many hydroponic systems are recirculating which allows buildup of unwanted contaminants in the plant root zone. Water treatment options used by municipal suppliers change over time and hydroponic growers should be Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November / December 2011

I love the smell of h2o in the morning

Recirculating solution culture systems such as NFT have less buffering capacity to water treatment chemical residues than organic media-based systems.

aware of the implications of these. Many years ago the main concern was the use of chlorine as a disinfection agent to destroy bacteria and human pathogens. Chlorine had the advantage in that it disinfected water effectively; however, residual chlorine in water sources, which could often be detected by smell, could be toxic to sensitive plants and where it built up in certain hydroponics systems. Also when chlorine reacts with organic matter it forms substances (trihalomethanes), which are linked to increased risk of cancer and other health problems. Chlorine was, however, quite easy to remove from water with the use of aeration or even just aging the water a few days before irrigating plants. In the 1990s it was found that some organisms such as Cryptosporidium were resistant to chlorine and the resulting health issues from this meant that drinking water regulations were changed and alternative disinfection methods began to be used.These included use of ozone and UV light, chloramines (chlorine plus ammonia) and chlorine dioxide. Filtration, flocculation, settling, UV and ozone used for water supply treatment are non problematic as far as hydroponic systems go, as they leave no residue and are effective. However, use of chloramines and some of the other chemicals by municipal water treatment plants may 22

Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/ December 2011

Water quality problems and their effects on plant growth are hard to diagnose, although root browning and stunted growth are common symptoms.

still pose problems where high levels are regularly dosed into water supplies. Chloramines are much more persistent than chlorine and take a lot longer to dissipate from treated water, so gardeners

Young seedlings and clones are particularly sensitive to water quality problems.

who are concerned can use a couple of different treatment methods just as those with aquarium fish often choose to do. There are specifically designed activated carbon filters that can remove most of the chloramines in a domestic water supply and also dechloraminating chemical or water conditioners available

in pet shops. Carbon filters must be of the correct type that have a high quality granular activated carbon and allow a longer contact time which is required for chloramines removal. Even then not every trace may be removed, but levels are lowered enough to prevent problems. Use of ascorbic acid (vitamin C) is also used in the industry, and by laboratories to remove chloramines from water after they have done their disinfection job. Chemicals are also added to drinking water to adjust its hardness or softness, pH and alkalinity. Water that is naturally acidic is corrosive to pipes and sodium hydroxide may be added to reduce this. Sodium is a contaminate we donâ&#x20AC;&#x2122;t need in hydroponic systems, but may be present at surprisingly high levels in certain water supplies. Domestic water softeners may also contaminate the water with sodium, which is not seen as a Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November / December 2011

I love the smell of h2o in the morning

Hydroponic lettuce plants are sodium sensitive and water supplies with high sodium levels may need RO treatment or frequent solution replacement.

problem for drinking, but can run amuck with a well-balanced hydroponic system and sodium sensitive crop.

What water problems may look like Itâ&#x20AC;&#x2122;s extremely difficult to determine if something in the water supply is

causing plant growth problems. Root rot pathogens may originate in water, but they can come from a number of sources, including fungal spores, blown in dust or brought in by insects. Mineral problems can be a little easier to trace if the water supply analysis is available to check levels of elements.

Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/ December 2011

Plant problems that may be caused by water treatment chemicals are difficult to diagnose as some plants are much more sensitive than others and the type of system also plays a role. Research studies have reported that chloramines in hydroponic nutrient solutions can cause growth inhibition and root browning in susceptible plants. One study reported that the critical chloramines amount at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight, however, the levels at which some other species would be damaged is as yet undetermined. Similar problems exist with the use of other water treatment chemicals; chlorine and hydrogen peroxide are good disinfection agents, but too much in the hydroponic nutri-

Good quality water is the basis of a clean and healthy hydroponic system; contamination issues should be cleaned up before adding water to a system.

“

“Hard water can occur in wells and municipal sources and has a tendency to form hard lime scale on surfaces and equipment.”

ent will cause root damage and just what is a safe level is dependant on a number factors such as the level of organic loading in the system.

Hard water Hard water is water that has a high mineral content, usually calcium and magnesium, with calcium present as calcium carbonate or calcium sulphate. Hard water can occur in wells and municipal sources and has a tendency to form hard lime scale on surfaces and equipment. A hard water supply is generally not a major problem for hydroponic gardens; calcium and magnesium are useful elements for plant uptake, however, high levels in the water can upset the balance of a nutrient solution Maximum Yield UK | November / December 2011

I love the smell of h2o in the morning

Seed germination is particularly sensitive to water quality, both in terms of chemical residues and pathogen spore contamination.

making other ions less available. Commercial growers routinely use hard water supplies and adjust their nutrient formulation to take into account the Ca and Mg naturally occurring in the water and also adjust for any alkalinity problems with water acidification. Smaller growers can use one of the many excellent hard water nutrient products on the market to get a similar effect.

Ground water – wells

“

Generally rainwater is low in minerals, but in the process of collection from roofs and other surfaces, can collect wind blown dust and fungal spores.”

Many commercial hydroponics growers use well water for hydroponic systems and adjust their nutrient formulations to suit the natural mineral content of their water supply. Smaller growers would be advised to find out what is in their well water source just to check for potential problems as water that has percolated through soils tends to pick up some minerals and in some areas, high levels of unwanted elements such as sodium or trace elements.Well water can also contain pathogens and may

Salt buildup and plant damage can occur where certain high mineral water sources are used and not adjusted for.

Maximum Yield UK | November/ December 2011

need treatment before use, although often it is just the mineral levels that need adjustment. Water from dams, lakes and springs is usually similar to well water, but can contain much higher revels of sediment, organic matter and fungal pathogen spores.

Rainwater

Rainwater collection can be a good way to bypass problems with municipal or well water in some areas; however, there are still some risks. Acid rain from industrial areas, sodium in coastal sites and high pathogen spore loads in agricultural areas can still occur. Generally rainwater is low in minerals, but in the process of collection from roofs and other surfaces, can collect wind blown dust and fungal spores. While this is generally not a problem for healthy plants, rainwater should be treated before use with young seedlings and clones where pathogens could infect sensitive tissue and open wounds.

Solutions to water quality problems Organic material such as coconut fibre gives a greater buffering capacity for some water problems, including residues from chemical water treatments, than solution culture systems. Drain-to-waste media systems are also useful where the water supply contains unwanted elements such as sodium as these aren’t as susceptible to the accumulation that can occur where the solution is recirculated over a long period of time.Where problems with unwanted minerals and very hard water exist, frequent changing and replacement of the nutrient in the system can also be useful to keep things in balance.Water with a high alkalinity will need considerably more acid to keep the pH down to acceptable levels than water with low alkalinity; however, by acidifying the water first before making up a nutrient solution or adding to the reservoir, much less acid will need to be added to the system to adjust pH over time.

Heat, distillation, reverse osmosis and UV treatment can all be used for pathogen control, with many small RO and UV treatment systems now on the market. UV filters for aquariums can be used for small hydroponic growers to treat water with good success, provided sufficient contact time is allowed. If excess minerals or unwanted elements such as sodium are present in a water supply, reverse osmosis (RO) or distillation can be used to remove these. Organic matter in ground water sources can be removed with settling and filtration and treatment with H2O2, while chemical contamination problems and removal of water treatment compounds are more easily treated with the correct type of activated carbon filter with a sufficient contact time.

There are a range of other treatment options that indoor gardeners can use to improve the quality of their water supply. If pathogen contamination is an issue, slow sand filtration is one of the most effective methods, although perhaps not that practical for those with limited space. Chemical disinfection methods for pathogen control include hydrogen peroxide, chlorine and other compounds, although care should be taken that most of the active chemical has dissipated before the water is used to make up the nutrient solution.

While it seems logical that pure, clean and demineralized water is the best place to start when making up a hydroponic nutrition solution, the possibility of creating a water source that has certain benefits for plants is a relatively new concept. Water is not just a carrier for essential nutrient ions, the nutrient solution becomes a whole biological system in its own right with organic matter, root exudates, various species of microbes including fungi, bacteria and their by-products (both good and bad), beneficial and unwanted mineral elements and a range of additives growers may be using. Some studies have found that inexplicable growth increases could be obtained using certain ground water sources compared to rain or RO (essentially pure) water to make up a hydroponic nutrient solution indicating there may be natural factors in such waters that have benefits. Not all ground water sources have this effect; in fact, some can have negative influences on plant growth. Furthermore, another essential plant nutrient—oxygen in dissolved form—is usually present in water supplies; however, some water treatment processes can drive much of the dissolved oxygen (DO) out of a water source. In theory it would be possible to not only remove those things in the water we don’t want—pathogen spores, unwanted minerals, chemical residues from water treatment—but to also boost the water with useful properties such as a high DO content, a population of useful and disease suppressant microbes and some natural and potentially beneficial minerals and compounds. One way of achieving this would be with the use of slow sand filters or mineral filters for water supplies that are inoculated with beneficial microbes and with oxygenation of the water for a few days before making up nutrient solutions or topping up reservoirs. Further down the track we may see quicker and easier methods of supercharging water for hydroponic systems, taking water quality to a whole new level of science. MY

Supercharged water for hydroponics

References: Effects of chloramines concentration in the nutrient solution and exposure time on plant growth in hydroponically cultured lettuce. Date S, Terabayashi S, Kobayashi Y and Fujime Y., 2005. Scientia Horticulturae Vol. 103 issue 3, pp 257.

Maximum Yield UK | November / December 2011

Wild

Plants Gone Pruning and Shaping

To achieve maximum yields it is essential to maintain a plant’s shape and remove any unnecessary or damaged growth. This is most important when growing indoors under artificial lights. Shaping plants under artificial lighting When growing under artificial lights its the best to keep plants short. This can be achieved by pruning and training.

Pruning: Once the initial three or four true leaves have formed, a plant can be made to possess two or more main stems by removing the terminal growing tip (figure 1a).The new main stems will grow from the axillary buds located at the remaining leaf nodes (figures 1a and 1b). Apart from being shorter than a single-stemmed plant of the same age, multiple stems allow a classic gobletshaped structure to form (figure 3a).This shape generally permits better airflow and light penetration throughout the foliage. Photosynthesis takes place mainly in young maturing leaves. Older leaves and those partly shaded photosynthesize less, thus drawing on the nutrition from young maturing leaves

Fig 1a To use HID lighting more efficiently, remove the terminal growing tip. This will produce a short and bushy (multi-stemmed) plant.

by Andrew Taylor

for their survival. For this reason, it is worthwhile removing the lower, older foliage.This practice is most relevant when growing under artificial lighting because the lower growth is furthest from the light and therefore has the least potential to photosynthesize and be of benefit to the remainder of the plant. Fig 3 Netting can be used to support For many species, major heavy top growth or to prevent plants structural pruning should from growing too high. only be conducted during the vegetative phase. Unless there is overcrowding or damaged growth, avoid stressing plants by pruning during flowering. Plant stress can be minimised by conducting major pruning Fig 4a Correct pruning in stages—allow plants technique: The “collar” mark is to rest for a week or so usually visible on woody growth. Cut immediately in front of this. between prunes.

Training: Upward

This cut will heal quicker and minimize the risk of pest attack and disease ingress.

growth can be restrained by erecting netting at an appropriate height. Once plants reach the netting they can either be: Fig 1b Axillary buds will grow to from vegetative or floral growth, or a combination of both

Maximum Yield UK | November/ December 2011

• Trained to grow horizontally (figure 3b). Many plant species will respond to this treatment by producing floral growth at the point where the stem is bent beneath the net. • Allowed to grow through the netting (figure 3a). However, if they grow too tall they can be bent down under the netting again.

Fig 4a Poor pruning technique: This style of pruning is slower to heal and attracts pest and disease problems.

Note: Pruning/ training/shaping requirements will vary from one plant species to another. For specific advice ask your local grow shop or nursery.

Overcrowded growth: Removing dense growth will allow better airflow and light penetration throughout the foliage. This will enable fruit to ripen more quickly.

Damaged growth: Broken, dying or dead growth is susceptible to disease and pest attacks and therefore should be promptly removed from the plant and the growing area.

Pruning Techniques: To minimise the threat of pests and diseases, use the following guidelines when pruning: Where to cut: When pruning, ensure that the cut is both neat and close to the stem (figure 4a). Doing this will help ensure that the cut heals quickly and completely, thereby minimising the risk of disease and pest attack (figure 4b). Pruning tools: Suitable tools for pruning include secateurs or a sharp blade. For a neat and clean cut, tools should be sharp and sterilised with bleach prior to use.

Plant Support: In many plant species, especially heavily fruiting plants, support mechanisms are needed to prevent the stem from breaking. Stem support can be achieved using the following methods: 1. Netting: Wide mesh netting stretched across the growing area acts as a support once the plant grows through it (figure 5a). However, this method will inhibit physical access to the plants where it is done over a large area. 2. String: String that is hung from a ceiling support and tied to the stem is especially effective for tall plants.The string is simply wound around the stem as the plant grows in height (figure 5b). Use a coarse grade of string to minimise the threat of it cutting into the stem. 3. Stakes: Rigid stakes can be used where plants are grown in pots.To avoid damaging the roots, position the stakes prior to planting. MY Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November / December 2011

}

Biology Versus Technology by Dr. J. Benton Jones, Jr.

There are two commonly heard expressions that relate to the subject of mechanical design and function (technology) versus plant biology: “Don’t fool with Mother Nature,” and “What are the unintended consequences?” 30

Maximum Yield UK | November/ December 2011

“

A tomato plant carrying a substantial fruit load under high atmospheric demand conditions will require at least one litre of water during the daylight hours.”

Modern Methods

Modern use of the nutrient film technique (NFT) hydroponic growing system is primarily confined to the growing of lettuce and herbs, short-term crops harvested before the root mass can begin to significantly affect the flow of nutrient solution down the trough.The length and slope of the trough is determined by growing conditions such as atmospheric demand. Recirculation of the collected nutrient solution requires additional volume and elemental reconstitution as well as aeration, filtering and sterilization in order to maintain both elemental sufficiency and to reduce the potential for root disease. Aeroponics is attracting attention, particularly applications of aeroponics designed for kitchen use, which have been commercially successful. Can aeroponics be applied to the commercial production of a greenhouse crop, such as a tomato? Such a system has been proposed. My first concern is the substantial electrical requirement for the pumping and cooling of the re-circulating nutrient solution. It is assumed that the

Maximum Yield UK | November / December 2011

Biology versus technology

design and operational characteristics of the nutrient solution delivery system will be sufficient to meet the water and elemental requirements of the tomato plant. Let’s remember that a tomato plant carrying a substantial fruit load under high atmospheric demand conditions will require at least one litre of water during the daylight hours.Therefore, just keeping the plant roots moist may not be sufficient to provide the water required to keep the plants from wilting, wilting that will reduce both fruit set and lower fruit quality. Therefore, failure to consider how to meet this biological requirement of the tomato plant will doom the best designed aeroponic systems. Biological procedures using predatory organisms are being proposed by those looking for an “organic” means of disease control in hydroponic growing systems. It’s important to realize that the presence of even a low population of disease organisms in a nutrient solution will significantly impact the plant, reducing root function and possibly resulting in plant death. Sterilization is required when a nutrient solution is to be recirculated because it must be kept totally free of any organism, whether beneficial or pathological. Again, biology is in control and no one can predict the outcome as each organism will take its toll with the plant being the loser. The head of an engineering company, a gentleman who had a keen interest in and considerable experience with growing plants, constructed a controlled environmental chamber for growing tomatoes. Being an expert in lighting system design, he installed what he thought was a light-sufficient system in terms of intensity and wavelength coverage. I even assisted him in the construction of a sub-irrigation growing system.The tomato plants grew extremely well, and then we waited for the plants to flower and set fruit. Unfortunately, only a few flowers appeared, while the

Maximum Yield UK | November/ December 2011

plants continued to grow vegetatively. Evidently there was not the proper wavelength mix or intensity of radiant energy present in the lighting system to promote flower initiation. An outdoor hydroponic tomato grower had devised a flood-anddrain growing system that worked very well, producing high yields of quality fruit. But in the design and operating procedures he did not consider what would be required if there was an electrical power failure and if root disease organisms invaded the recirculating nutrient solution. An electrical power failure did occur on a hot Sunday afternoon when the plants were setting fruit.Without a source of auxiliary power he had to hand-water each rooting vessel using city drinking water, which under normal conditions he considered unsuitable for his hydroponic growing system—he had been using a reverse osmosis water treatment system for generating the water for making the nutrient solution.To his surprise, however, the plants survived, showing no effects from the change in water quality. But what he was not prepared to deal with was Pythium, a deadly root disease organism that was waiting for the ideal time to strike—and it did, killing all his plants within 48 hours! Unable to bring the disease under control, the grower’s whole operation failed. If he had sterilized the recirculated nutrient solution and added

Plants grow best when their roots are maintained in a consistent nutrient solution environment.”

composted pine bark to the gravel rooting medium, Pythium could have been kept out or at least kept under some manageable degree of control. A greenhouse tomato grower thought that he could save on his heating costs by setting the nighttime greenhouse air temperature right at the lower end of the optimum recommended level.What the grower was not prepared to deal with was the condensation that then accumulated on the inside of the greenhouse.The condensation formed into droplets of water that fell on the plant foliage, resulting in the death of the tissue where the droplets hit (initially he thought that a disease organism was the cause), thereby reducing the rate of photosynthesis, slowing plant growth and reducing fruit yield. He was unaware that his tomato plants would be slow in setting fruit under these conditions as well, since nighttime air temperature can also affect fruit set. I have been surprised how well plants will grow under a range of different conditions involving nutrient solution formulations, frequency of irrigation and varying characteristics of the rooting medium. However, the challenge is to balance these three factors for maximum plant performance. I have visited the best greenhouses and seen growing system designs with plants growing well, but not at their maximum potential—that would require carefully regulating the nutrient element environment around the plant roots, something that is not easy to do. One of most impressive hydroponic growing experiences I have ever witnessed was an experimenter whose objective was to determine what effect the ratio of nitrate to ammonium-nitrogen in a nutrient solution formulation would have on bean yield using

green beans as the test crop.The rooting medium was perlite placed in eight litre buckets. Having determined the water-holding capacity of the perlite, sufficient nutrient solution was added to just saturate it. Each morning, the perlite was leached with water to remove the previous day’s nutrient solution residue, then sufficient fresh nutrient solution was added to just saturate the perlite again. Plant growth and treatment difference results were significantly greater than had been obtained in a previous hydroponic experiment using the same rooting medium and nutrient solution formulation, the only difference being that the previous day’s nutrient solution residue was not leached from the perlite before fresh nutrient solution was added. This suggests that plants grow best when their roots are maintained in a consistent nutrient solution environment. In other words, best plant growth occurs when plant roots are growing in an infinite volume of nutrient solution whose elemental composition remains unaffected by root activity. This also raises another question regarding nutrient solution

Maximum Yield UK | November / December 2011

Biology versus technology

The presence of even a low population of disease organisms in a nutrient solution will significantly impact the plant, reducing root function and possibly resulting in plant death.” formulations and their use, suggesting that the dominating factor in their effectiveness is the set of biological characteristics of the root itself, the lesser factor being the set of characteristics of the surrounding rooting environment.There are nutrient solutions currently being marketed that are formulated to achieve certain results—such as stimulating vegetative growth, flowering and fruit set and enhancing root “availability” of the essential elements in various rooting media, but it is the root itself that determines its function irrespective of what nutrient solution formulation is used. Those who would promote these nutrient solution formulations should first be prepared to define to the user under what conditions their product will be able to accomplish the objectives described.

Old School Style

I was present at the Hydroponics Worldwide: State of the Art in Soilless Crop Production conference held in Honolulu, Hawaii in 1985. At that conference, Dr. Allen Cooper and his colleagues described their newly developed nutrient film technique (NFT) method for growing plants hydroponically without the use of a rooting medium.With this method, the plant’s bare roots are set in an enclosed slopping trough or channel and at its top, nutrient

solution is periodically introduced to flow down the trough, bathing the roots, as the method for supplying water and essential elements to the plant. At the end of the trough the nutrient solution can be either discarded or collected for recirculation.The method described was relatively simple in its design, since it was claimed that folded plastic sheeting of any width and length would do as long as the slope was sufficient to allow for the gentle, even flow of nutrient solution down the trough. Many at the conference saw this as a revolutionary advancement in hydroponic technology and high praise was given to Dr. Cooper and his colleagues. Over a number of years many tried the NFT concept, devising various trough configurations to suit particular growing conditions and plant species.What had seemed at first to be a perfectly designed mechanical and functional system was rendered ineffective, however, by the biological characteristics of the plant and its roots. What neither of the participants at the conference nor Dr. Cooper and his colleagues had considered was that as the root mass in the trough increased in size, the flow of nutrient solution down the trough was impeded. Rather than passing through the root mass, the introduced nutrient solution flowed over the top and along the edges of the trough. In fact, as the root mass enlarged, it acted like a dam, preventing the free movement of nutrient solution down the trough. Portions of the root mass would become anaerobic, resulting in death due to the lack of oxygen. Even with free movement down the trough, oxygen and elemental contents in the nutrient solution decreased, with the plants at the end of the trough exposed to a nutrient solution quite different in composition from that introduced at the head.Various attempts were made to overcome these problems by changing the width and length of the trough as well as by altering the slope and the nutrient solution flow rates. Changing the design of the trough from a “U-shaped” form to a “W-shaped” form was tried, with the base of the plant being placed on the top of the “W” peak, equally dividing the plant roots on both sides.With the “W-shaped” trough design various nutrient solution formulations and water could be alternately sent down either side of the trough.

Lesson Learned?

The message from all of these experiences? In the contest between mechanical design and function versus plant biology, plant biology will always determine the outcome! MY

Maximum Yield UK | November/ December 2011

TDS Metres, Conductivity Conversion Factors by Rob Samborn

Though there is a close relationship between TDS and electrical conductivity, they are not the same thing. Total Dissolved Solids (TDS) and Electrical Conductivity (EC) are two separate parameters. TDS, in layman’s terms, is the combined total of solids dissolved in water. EC is the ability of something to conduct electricity (in this case, water’s ability to conduct electricity). The only true method of measuring TDS is to weigh residue found in water after the water has evaporated.You know those spots you see on a glass after you wash it and let it air dry? That’s TDS! That residue has mass, and it’s possible to weigh it, but if you’re not in a lab, it can be tricky thing to do. Therefore, we can estimate TDS levels based

on the conductivity of the water since the hydrogen and oxygen molecules of the H2O carry almost no electrical charge.The EC of most other metals, minerals and salts will carry a charge. A TDS metre measures that EC level and then converts it to a TDS measurement. Since different metals, minerals and salts will be more or less conductive than others, there are different conversion factors that can be used.

ppm (parts per million) is the most commonly used scale to measure TDS (Total Dissolved Solids).

µS (micro-Siemens) is the most commonly used scale to measure EC (Electrical Conductivity).

TDS and Conversion Factors EC: There is no conversion for electrical conductivity. TDS - NaCl: 0.47 to 0.50 TDS - 442: 0.65 to 0.85 TDS - KCl: 0.50 to 0.57

Converting between different scales PPM to µS: The conversion factor of the TDS metre must be known. Once known, the conversion factor should be multiplied by the TDS level. PPM to PPT: Divide by 1,000 (1,000 ppm = one ppt) µS to mS: Divide by 1,000 (1,000 µS = one mS) MY

Maximum Yield UK | November / December 2011

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

The

ABCs

of Hydroponics

For the beginner, indoor gardening and hydroponics can be a bit daunting. Technological terms and sophisticated language are a regular occurrence and can cause the new gardener to give up too early due to misunderstanding. Thankfully, help is here. The following terms are commonly used in hydroponics. Before too long you will be relaxing with your feet up while your indoor garden thrives.

Acid: an acidic solution that has a pH below 7.0 Alkaline: a term describing a grow medium or nutrient solution with a high pH (over 7.0) Ballast: a device used to regulate the flow of electricity to match the needs of a specific bulb Bolt: a plant that has gone to seed prematurely Burn: leaf tips that turn noticeably dark from excess fertilizers or salts Chitin: a tough, protective, semi-transparent substance, primarily a nitrogen-containing polysaccharide, forming the principal component of arthropod exoskeletons and the cell walls of certain fungi Clone: a plant that has been produced through asexual reproduction (e.g., cuttings, layerings and tissue culture) Cotyledon: a leaf of the embryo of a seed plant, which upon 38

Maximum Yield UKâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/ December 2011

germination either remains in the seed or emerges, enlarges and becomes green (also called seed leaf) Cytokinin: any of a class of plant hormones that promote cell division and growth and delay the senescence of leaves Damping off fungus: a disease that attacks young seedlings and cuttings causing them to rot at the base Grafting: uniting (a shoot or bud) with a growing plant by insertion or by placing in close contact Guano: a substance composed chiefly of the dung of sea birds or bats Harden off: to gradually acclimatize a plant to a harsher environment Humus: a brown or black organic substance consisting of partially or wholly decayed vegetable or animal matter that provides nutrients for plants and increases the ability of soil to retain water

Leaf curl: leaf malformation indicative of overwatering, overfertilising, lack of magnesium, insect damage, fungus damage or negative tropism

Microbial: a minute life form; a microorganism, especially a bacterium that causes disease pH: a scale from 1.0 to 14.0 that measures acid to alkaline balance

Photoperiod: the relationship between the length of light and dark in a 24 hour period Polyploid: an organism with more than two sets of chromosomes Pyrethrum: natural insecticide made from the blossoms of various chrysanthemums Reverse Osmosis (RO): water that has had all of its contaminates and salts removed Spidermite: any of various small red mites of the family Tetranychidae that feed on vegetation, causing damage to the leaves Systemic: a term used in reference to a disease within the plant tissue, not initiated from the external cells Thrips: any of various minute insects of the order Thysanoptera, having usually four narrow wings fringed with hairs, and many of which are major pests of various plants and trees Vermiculite: mica processed and expanded by heat Wetting agent: compound that reduces the droplet size and lowers the surface tension of the water, making it wetter Whitefly: any of various small whitish homopterous insects of the family Aleyrodidae, having long wings and a white waxy body, often injurious to plants Wick: part of a passive hydroponic system using a wick suspended in the nutrient solution; the nutrients pass up the wick and are absorbed by the medium and roots Worm castings: the nutrient rich fertilizer created by earthworms MY Maximum Yield UKâ&#x20AC;&#x201A; |â&#x20AC;&#x201A; November / December 2011

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

Vitamin P:

Plasma Lamp Technology by Philip McIntosh

As if you didn’t have enough choices for grow room lighting. Plasma lamps are getting positive reviews from the industry and independent researchers. Read on for a description of plasma, and the advantages of this popular technology. > >

Maximum Yield UK | November/ December 2011

Plasma

Before asking the question ‘what is a plasma lamp?’ it seems useful to first ask—‘what is a plasma?’ According to WolframAlpha (the computational knowledge engine at (www.wolframalpha.com) a plasma is “a fourth state of matter distinct from solid or liquid or gas and present in stars or fusion reactors; a gas becomes a plasma when it is heated until the atoms lose all their electrons, leaving a highly electrified collection of nuclei and free electrons.” That’s exotic stuff.

The modern plasma lamp is a descendant of the electrode-less lamps first demonstrated by Nikola Tesla in the late 1800s. The temperature of a plasma found inside a star or fusion reactor can reach millions of degrees, and obviously that kind of temperature could not be maintained in any feasible grow light. The basic structure of the plasma is the same in both, though; it’s just at a lower pressure in the grow light, so the temperature is a lot more manageable.

Maximum Yield UK | November / December 2011

Vitamin P: Plasma Lamp Technology

Plasma lamps are available for use in a variety of applications— such as building, parking lot and street illumination, as well as specialty and horticultural lighting—and there are several companies currently active in the marketing of these products.

Principle of operation

The modern plasma lamp is a descendant of the electrodeless lamps first demonstrated by Nikola Tesla in the late 1800s. Electrode-less lamps are excited by electrical energy introduced from outside the lamp enclosure, unlike more familiar lamps in which power is passed directly to an electrode mounted inside a bulb.

An ample heat sink is provided to carry heat away from the back of the fixture so that the temperature in front of the light is actually quite low.

Maximum Yield UK | November/ December 2011

Nikola Tesla

Although the exact construction of a plasma light varies from one manufacturer to another, the principle of operation is the same. There are three basic components: first, the emitter, which includes the bulb and its internal components; second, a radio frequency (RF) source; and third, a power supply and control circuitry. A functional grow light also includes a reflector, UV shielding, RF shielding (to prevent interference with computing and communication equipment) and a heat sink. A plasma bulb contains either a proprietary gas mixture and a metal halide or an inert gas mixture and a dab of sulphur. In one popular bulb variety, an RF electric field is set up around and focused toward the bulb through a dielectric (non-conducting) waveguide. The energy of the electric field ionizes the

gas, creating a plasma. The plasma in turn vapourizes the metal halide (or sulphur), which glows with a bright white light. Spectral analysis of the emitted light shows that it compares favourably to natural sunlight over the range of visible wavelengths, although the spectrum of the lamp will differ depending on manufacturer models and dimming.

When first examining a plasma lamp you might be surprised by how small the bulb is.

Since plasmas have a reputation for existing at rather high temperatures, one might think that a plasma lamp would get very hot—maybe even hotter than a high intensity discharge (HID) lamp. This is not the case, however: an ample heat sink is provided to carry heat away from the back of the fixture so that the temperature in front of the light is actually quite low. While the UV output of sulphur plasma fixtures is quite low, metal halide plasma lights do generate a certain amount of ultraviolet (UV) radiation. In one fixture, a transparent shield in front of the bulb absorbs the harmful short wavelength UV-C rays, blocks most of the UV-B rays and lets the UV-A ones pass through.

• Plasma lamps are dimmable and can be operated from 20 to 100 per cent of full output. • Lamp power supplies can easily be controlled remotely. • Fast turn on and restart time. What about cost? Plasma lights are significantly more expensive up front than comparable HID lights—a single unit runs about $1,400, compared to several hundred dollars for an HID system. However, considering the savings in bulb replacement and electricity consumption, the total cost of ownership over a period of years is competitive for plasma lighting.

Plant response to plasma lighting

Published data on plant growth under plasma lamps has shown promising results so far. In a paper published in The Journal of Experimental Botany, researchers reported that cucumber plants grown for 13 days using a quality brand name of plasma ASspectrum lamps achieved a dry weight 2.3 times greater than plants grown under fluorescent tubes (FT), and 1.6 times greater than plants grown under high-pressure sodium (HPS) lamps. The AS-spectrum plants were also four to five times taller than the FT and HPS-grown plants. This was a relatively short experiment, however, and it did not provide data for a full life cycle and fruiting of the cucumbers. Additional research in 2010 showed that cucumber fruit of “standard size” were produced in 10 fewer days than is normally

Advantages of plasma lights

Plasma lights have characteristics that set them apart from other sources of photosynthetically active radiation (PAR). When first examining a plasma lamp you might be surprised by how small the bulb is—a plasma bulb is tiny compared to a typical HID lamp or fluorescent tube. A plasma bulb is actually closer in size to a light emitting diode (LED) than any standard type of lamp, its small size providing excellent luminous efficiency. Some important features of plasma lamps include: • Long bulb life—expected up to six years, with little change in output intensity or spectral characteristics. • Plasma lights use up to 50 per cent less energy than other light sources, drawing only a few amps per unit. • Low heat output means lamps can be placed close to plants. • No orientation constraints. Lights can be mounted in any direction, with no reduction in bulb life expectancy. Plasma lamps should be mounted according to manufacturer’s specifications, however, since some drivers do mandate specific mounting limitations.

Cucumber plants grown for 13 days using a quality brand name of plasma AS-spectrum lamps achieved a dry weight 2.3 times greater than plants grown under fluorescent tubes.

Maximum Yield UK | November / December 2011

Vitamin P: Plasma Lamp Technology

A grower’s perspective “Plants have evolved under a full spectrum. It’s what they not only desire but need to reach their fullest potential.

achieved in commercial cultivation. Research conducted by the TNO Horticulture Field Lab (an independent research organization in the Netherlands) tested several lamps in 2010—including plasma lamps—and obtained variable results, but did note excellent fruit quality of one of the plasma brand of lights. In 2011, researchers grew basil, snapdragon, tomato and zinnia using either HPS or plasma lights. The lamp heights were adjusted so that all plants received similar levels of PAR, with a supplemental light period of 18 hours per day in addition to natural light in a greenhouse. Snapdragon and tomato showed slightly greater dry weights under plasma, while basil and zinnia showed slightly less. In general, though, there was little difference between treatments.

Sean Coker, an indoor gardening retail storeowner, has been conducting experiments comparing the results obtained with plasma, metal halide (MH) and HPS lamps. He has grown a variety of plants, including basil, tomatoes, squash, various spices and several varieties of flowers. In his research, Coker positioned plasma lights as close as 20 centimetres from the plants with no detrimental heat effects, and he reports that light spread and penetration into the canopy has been good. In discussing one plasma model he says, “The lamp is compact, but the built-in hood is designed to spread the light across a 1.2 by 1.2 metre area quite evenly. In our store we have three units in operation for people to see.Two of the plasma units are used to produce high-quality basil that we sell to a local Italian restaurant for making pesto.The rate of growth under these lights is superb. Another light is used for a full 1.2 by 1.2 metre table of tomatoes.The plants grow fast, have copious flowers and set fruit in about three weeks.” In talking to Sean it is clear that he is sold on plasma lights. “We’re amazed at the performance of the lights. Everyone who comes in the store is amazed as well. Everyone who has bought a light has come back for more, and that’s the best marketing of all.” Could the era of the red and blue bulb be ending? Probably not yet, since it takes time for a new technology to be proven and become established, although the cost of plasma lights will no doubt come down as the market grows and more manufacturers get in the game. Coker sums it up this way, “Plants have evolved under a full spectrum. It’s what they not only desire but need to reach their fullest potential.Yes, one can take an isolated portion of the spectrum, like blue or red, power up the lights and make them work, but a much lower-power full spectrum can work just as well.” MY

References

Anonymous, (2010), “Photosynthetically active radiation tests cucumber plants, week one to 11”, Greenport Campus/TNO Horticulture Field Lab, <http:// www.plasma-i.com/plasma-par-test.htm> accessed June 6, 2011 Baars, A. (2010) “Cucumber growth under the new standard horti-mix plasma bulb shows excellent results”, <http://www.plasma-i.com/cucumbers.htm> accessed June 6, 2011 Hogewoning et al., (2010) “An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra”, Journal of Experimental Botany, March 4, 2010, <http://jxb.oxfordjournals.org/content/ early/2010/03/04/jxb.erq005.full> accessed June 5, 2011 Luxim Corporation, <http://www.luxim.com> accessed June 3, 2011 Newman, S. (2011), “Light emitting plasma diode lights for growing plants in greenhouses”, CSU Extension Greenhouse Advisor, <http://ghadvisor.blogspot. com/2011/03/plasma-emitting-diode-lights-for.html> accessed June 7, 2011 Plasma International, GmbH <http://www.plsmi-i.com> accessed June 3, 2011

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

YOU TELL US

Vicky Wainman

equipment for small nurseries and enthusiastic amateurs. Renowned for our versatility and expertise, Hotbox also manufactures various lighting units, circulation fans and propagation equipment. Due to the high level of export business, the company duly changed its name to Hotbox International Ltd. Hotbox International offers the flexibility and friendliness of a small firm and all its virtues, with the experience and technical excellence gained from years of working to meet clients’ needs and with the backup from within the larger group of Vicky Wainman, sales coordinator for the Cambridge Glasshouse Company. Hotbox International, The result is the highest quality equipment produced for client shares the company’s and market requirements worldwide. beginnings, instructs MY: What products in the Hotbox International line are you on the best way to excited about right now? deliver CO 2 in the grow room and raves Vicky: These are exciting times in general for Hotbox International as a number of products are achieving major inabout the majorly successful Sulfame. dustry segment success. The Sulfume is just one product we offer that is regarded as a market leader. The unique temperature control enhances performance, provides safety against fire and stops damaging oxide release, thus only releasing pure sulphur. It is also highly energy efficient in operation when compared to other similar products on the market.

Maximum Yield (MY): What’s the story behind Hotbox International’s beginnings? Vicky Wainman: Hotbox International Ltd. is a world leading manufacturer of quality greenhouse heating and propagation equipment for hobby and amateur growers. Now based in Brough, East Yorkshire, Hotbox has grown from small beginnings, first established in 1976 and originally based in Hampshire, to now widely recognised as the leader in greenhouse

Maximum Yield UK | November/ December 2011

MY: What is the best way to deliver CO2 in the grow room? Vicky: Hotbox CO2 Generators enrich the atmosphere and encourage plant growth. There are a number of models to choose from, suitable for various requirements, which will increase CO2 to 1,000 ppm, achieving an optimum growing environment and plant stimulus. They are inexpensive to operate, run on propane or natural gas (all of the CO2 generator are supplied as propane with a conversation kit for natural gas) and easy to install—simply attach to supply, plug in and switch on. Hotbox also has another unique product in the Heatwave root zone heating system, which is the only product available that can guarantee an even spread of heat across the entire surface. The heating element is laminated in sheets of foil, resulting in no cold or hot spots, just even temperatures, perfect for root development. MY: What products do you offer for grow room/greenhouse environmental control? How do they work? Vicky: Both the electric and gas Hotbox heaters are very popular greenhouse heating systems all thermostatically controlled and ideal for providing frost protection.

MY: What types of instrumentation (hygrometers and thermometers) do you offer and what situations and growers are they suitable for? Vicky: The range of Hotbox thermometers and hygrometers all come with maximum/minimum memory allowing you to easily check and ensure the environment is optimum for your plants (indoor temperature range: -10ºC to 50ºC, indoor hygrometer range: 25 per cent relatively humidity to 98 per cent relative humidity, easy to use and a terrific value). Hotbox continually develops new products. For example the new Waterwand Solar Rainwater system ensures your plants grow better with regular feedivng and watering at just the right time and correct, automatic dosage every three hours throughout the day. Another new addition to

the Hotbox range are humidifiers that enrich the air with a fog of moisture, thus creating the optimum environment for your plants. MY: How can you ensure the utmost quality and safety in your products? Vicky: Hotbox International offers quality products with long life expectancies, all at affordable prices. Hotbox International enforces strict quality standards on all products, which ensures that consistent quality and reliability are guaranteed. MY: What makes Hotbox International the leader in greenhouse heating? Vicky: Hotbox’s clients all agree that value for money combined with long life and superior performance make Hotbox the industry sector leader. MY

Hotbox

INternational Maximum Yield UK | November / December 2011

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Oh, but how dreary winter is for the gardener stuck inside watching snow pile up against the window. The prospect of the looming holiday season does little to alleviate their doldrums. Their outdoor garden after all is under piles of snow and spring is many months off. If there was only something their friends could do to get that spark back in their eyes. But what? How about gifts to enable these forlorn gardeners to plan for the upcoming growing season, or better yet, get a garden started indoors. There is much preparation to set up a grow room indoors. And you can help them out by getting them the supplies they need.

Gardener’s journal - This is one of those things that gardeners will likely never purchase for themselves and yet it could be a vital tool. Knowing what happened in year’s past can be very helpful in establishing trends and patterns. A journal is much better than relying on memory.

Garden books - There are literally hundreds of gardening books available. Which to pick? Well, if you really love the gardener in your life how about one of each, an entire library?

UK | November/ December 2011 Maximum Yield UK | November/

S u b s c r i p t i o n to gardening magazines - This is in the same vein as with books only these come continually with loads of fresh ideas determined to inspire the gardener even in the dead of winter.

Seedling heat mat - With or without a greenhouse these would surely come in handy to get those reluctant seeds to germinate nicely by distributing heat evenly to the bottom where it’s needed. Grow lights - There exists a huge variety to choose from and they vary so greatly there is bound to be a grow light setup to fit any indoor gardening hobbyist’s style. What gardener longing for spring and wishing to get their hands into some soil wouldn’t want any of these things? The answer is none. So go off and buy the lot and don’t forget to buy something for yourself.You should be gardening too. MY

NUTRIENT DEFICIENCIES:

REACTION AND PREVENTION PART ONE

by Matt LeBannister

Understanding the symptoms of different nutrient deficiencies can make diagnosis and treatment simple. A prompt reaction to nutrient deficiencies can make all the difference and keep your plants healthy and your harvests bountiful.

Gardeners are extraordinary people. Most are extremely caring and nurturing toward their plants, spending countless hours in the grow room fussing over them, making sure they are happy and healthy. Many gardeners are so engaged

Nitrogen, iron and magnesium deficiencies are common in plants and each presents symptoms that involve different leaves yellowing. Plants that are deficient in nitrogen have their oldest leaves on the bottom of the plant turn

“Many gardeners are so engaged in their plants’ wellbeing that they treat them more like family than flora.” in their plants’ wellbeing that they treat them more like family than flora. When plants just do not seem to be growing to their full potential, though, it is no wonder that many growers work themselves into a frenzy searching through all avenues of botanical knowledge in search of an answer. We can find ourselves reading every book and article available on the subject— anything to save our beloved leafy and flowering friends from damage and unnecessary trauma.

yellow, magnesium-deficient plants have the leaves in the middle of the plant turn yellow and young yellowing leaves at the top of plants are a sign of iron deficiency. Each of these deficiencies is caused either by the use of poor quality nutrients, fluctuating pH levels or high EC readings, causing nutrient lockout. This article will explain how to spot and treat three relatively common problems—phosphorous, potassium and calcium deficiencies.

Maximum Yield UK | November / December 2011

Nutrient Deficiencies: Reaction and Prevention Part One

and bat guano are excellent sources of organic phosphorous. Deficiencies can also be caused by fluctuations in pH levels. If pH levels drift lower than 5.8 or climb higher than 7.0, plants become unable to absorb phosphorous, but checking and adjusting pH more frequently can solve the problem if this is the case. A plant may also become deficient in phosphorous if the soil or soilless medium remains too wet for too long, which can occur in hydroponics if the water is not properly aerated. Phosphorous deficiencies will also occur if there is too much iron or zinc present in the soil, soilless medium or hydroponic solution, which causes the phosphates to become chemically bound, making them unavailable to the plant. To remedy this problem,

leaves will also rise, causing protein in the leaf ’s cells to burn. Leaf tips and edges burn first because this is where evaporation levels in the leaf are the highest, but eventually the leaves will turn completely dark yellow to rust brown, curl up and fall off. The stems can also become weak. Potassium deficiencies can be caused by not using quality nutrients. For those gardeners who are organically inclined, kelp meal and greensand (iron potassium silicate) are good sources of organic potassium. Wood ash is fast-acting but should be used in moderation because it is very alkaline, with a pH level as high as 10. To counteract this, mix the wood ash with water and balance pH levels before feeding it to your plants. Potassium deficiencies can also be caused by nutrient lockout as a result of an overly high EC—when salinity levels become too high, plants are unable to absorb potassium. To remove toxic levels of nutrients from the growing medium it must be flushed with straight pH-balanced water or a clearing solution, which can

Phosphorous is a macronutrient that all plants require to photosynthesize and is also a component of plant DNA, proteins and many enzymes. Plants require phosphorous in larger “Plants require phosphorous in larger amounts during amounts during the blooming or fruiting the blooming or fruiting stage of growth.” stage of growth. If you look at the NPK of most bloom-enhancing products you will see flush the growing medium with straight, be done every so often to prevent the that phosphorous is usually the most pH-balanced water or with a nutrient buildup of salts from reoccurring. Once abundant ingredient. clearing solution. Checking EC levels the medium is flushed plants should only There are many symptoms associated frequently can prevent nutrients from receive a complete nutrient solution with a plant suffering from a phosphoreaching toxic levels. that is specialized to the plant’s specific rous deficiency. The stems or leaves of the Potassium is a macronutrient used stage of growth, which when combined plant will begin to turn a bluish-purple by plants through all stages of growth with more frequent EC measurements hue and sometimes develop spots. When that aids the manufacture of sugars and should cure any potassium deficiency and the deficiencies are not treated properly encourages healthy root growth. Potasprevent the problem from plaguing your the leaf tips will darken as they contort sium is necessary for the production of plants again. downward, eventually shrivelling up, dryflowers, fruits and vegetables and is also Calcium is a secondary nutrient that ing and falling off. Plants that receive an vital to a plant’s resistance to bacteria and is essential to plant growth, required in inadequate amount of phosphorous durmould. Plants suffering from a potasabundance by fast-growing fruit and ing the fruiting and flowering phase will sium deficiency often become diseased, vegetable plants—sometimes as much not fruit or flower as well as their healthy as their immune systems are not working so as the macronutrients. Calcium is counterparts, and if the problem persists at the same level as healthy organisms. needed for cell growth and reproducand becomes severe the plants will someSymptoms of potassium deficiency usution and is also very important for root time not fruit or flower at all. ally begin with the older, lower leaves on growth, as each root tip must contain Phosphorous deficiencies can be caused the plants, which will begin to develop calcium to grow. by not using quality nutrients. For the brown tips and edges. The internal temThe initial symptom of calcium defiorganic gardeners, steamed bone meal perature of a potassium-deficient plant’s ciency is overall stunted growth, with 52

Maximum Yield UK | November/ December 2011

“If the humidity is too high in your grow room plants can also become calcium deficient, because the high humidity forces them to close their stomata—the part of the leaf from which water is evaporated.” young leaves appearing dark green and smaller than the leaves on healthy plants. The young growth will eventually turn a yellow to purplish hue and start to contort, finally shrivelling, dying and falling off. Plants experiencing a calcium deficiency will have a difficult time producing flowers, which will fall off or not even grow at all. If fruit is produced it will be stunted, and the amount will be far less than that generated by an average healthy plant. Calcium deficiencies are less common indoors than phosphorous and potassium deficiencies, but there are a number of reasons why a plant could become calcium deficient. Naturally, not using quality nutrients that have enough calcium can be a problem, and like all deficiencies the use of a quality hydroponic solution can prevent the problem from ever occurring. If the nutrient does not contain adequate amounts of calcium, watering with a half teaspoon of hydrated lime per four litres or adding dolemite lime to the soil/soilless growing medium are both great ways to give your plant the calcium it needs. If the humidity is too high in your grow room plants can also become calcium deficient, because the high humidity forces them to close their stomata—the part of the leaf from which water is evaporated— thereby shutting down transpiration. Transpiration is the process by which water evaporates out from the leaves, which in turn causes the plant’s roots to draw up water. No transpiration means there isn’t any water being sucked up into the

plant, resulting in no nutritional intake. Calcium is a mobile nutrient and shutting down transpiration means it can no longer be moved through the plant. Keeping the humidity level lower than 70 per cent will keep the leaves’ stomata open and calcium will continue to circulate throughout the plant. Plants can also become deficient in calcium if the pH levels in their growing medium and nutrient solution are allowed to fluctuate. Nutrients cannot be absorbed when the pH levels drift from their ideal range, which can vary from plant to plant and can depend on the growing medium being used. It usually falls somewhere between a pH of 5.8 at the lowest and 6.8 at the highest, and a reading outside of this level will generally result in nutrient deficiencies. Simply checking your pH frequently can prevent deficiencies like this from ever occurring. Gardeners seem to have a real lust for knowledge—they are always on a quest to learn new things and understand their plants better, right down to the cellular level. Knowledge and experience truly are the best tools in the grow room, so a successful grower will make it his business to never stop learning. The knowledge you gain can be used to cure or even totally prevent nutrient deficiencies, keeping your plants healthy and your harvest rich! MY

Maximum Yield UK | November / December 2011

by Brian Mack

Reasons Beneficial

Soil Microbes Rock

When world record setting giant vegetable growers suggested that beneficial soil microbes had been a major factor in the setting of their new records, growers started cracking open their college biology books. After their fame became more widespread, there was an outpouring of praise by growers for the beneficial soil fungi Mycorrhizae. Competitive growers coast to coast began experimenting with the new found soil fungi and now Mycorrhizae is generally accepted as the essential factor in soil treatment for serious growers. As top growers began their own research and commenced experimenting with these notoriously beneficial soil microbes, the use of Trichoderma and compost teas started sharing the spotlight with Mycorrhizae. Growers continue to push the microbial envelope reaching for every pound and square metre Mother Nature can possibly 54

Maximum Yield UK | November/ December 2011

provide. Only this past year a handful of competitively-experienced growers began experimenting with yet another promising soil microbe; it is many times smaller than even the microscopic fungi mycorrhizae, and it’s called Azospirillum. Azospirillum is making its mark globally; already prevalent in use in India, Israel, Arab states, China, Brazil and the Philippines, among other nations, it’s creating quite the agricultural spur. Over two decades in development, Azospirillum is creating records for increased yields in “real-world” field conditions often by five to 20 per cent. Increasing yields results in a decreased need for costly fertilisers, which has spurred the United Nations to recommend Azospirillum’s use in poor countries where a fluctuation in fertiliser cost can result in starvation, especially among the poorest subsistence farmers.

for less than the chemical alternatives. The real world use of Azospirillum is longestablished and studied, but its use by competitive growers is in its infancy. Companies are hoping to improve upon 20 years of positive results from throughout the Asian and South American continents by leveraging their technical know-how. Worldwide results show generally five to 20 per cent yield increases with substantially less fertiliser as the norm when using this microbe, but what will the experience of the backyard and indoor gardener be with Azospirillum? Expectantly, within a handful of years, competitive growers will reach the generally accepted consensus on the bacteria’s usefulness to the sport of competitive growing. Until the jury is in on Azospirillum, the multi-decade proven track record of this beneficial microbe is undeniably worth taking a look at. MY

“Already prevalent in use in India, Israel, Arab states, China, Brazil and the Philippines, among other nations, it’s creating quite the agricultural spur.”

Upon the initial discovery of Azospirillum, it gained praise for its ability to produce a form of nitrogen that plants can easily use. Certainly this was the reason that the beneficial bacteria yields were higher than that of the control groups. However, in recent years research has shown that the increased root growth and overall plant vigour is not connected to nitrogen fixation alone; as is the case with nature, the answer is elegantly simple: Azospirillum’s nitrogen-producing gene was “turned off,” yet its ability to produce more root mass, higher dry weight, increased survivability, increased crop yield and increased root hairs remained constant. One factor after another was ruled out and it’s now an accepted fact that Azospirillum synthesizes the plant growth hormone called IAA (indole-three-acetic acid) in a way that is easily utilised by plants. Although many scientists have tried, none have been able to efficiently reproduce Azospirillum’s delivery method of IAA to the plant, a way which ensures maximum utilisation by plants. IAA increases lateral root growth and root hairs, effectively boosting plants’ overall root surface area and increasing their ability to access nutrients. Furthermore, Azospirillum works symbiotically with Trichoderma and Mycorrhizae to maximise growth and production rates. This tripartite relationship provides leverage against natural events such as soil pathogens, drought, shock, stress and infestations. The relationship of these three microbes has been proven to increase farm production among the poorest farmers in the harshest of conditions, while delivering more food to the table

Further research:

Azospirillum’s effect on common crops: pages 38-57 http://www.bashanfoundation.org/gmaweb/ pdfs/Azospirillumreview.pdf Increases root surface area by increasing root hairs: http://www.bashanfoundation.org/cassan/ cassanhair.pdf Azospirillum and vegetable crop production: http://www.bashanfoundation.org/barassi/ barassidynamic.pdf Azospirillum is a non-pathogenic bacterium for use on plants: http://www.bashanfoundation.org/gmaweb/ pdfs/azospirillum.pdf Azosprillum produces the plant hormone IAA: http://www.bashanfoundation.org/gmaweb/ pdfs/chlorella-iaa.pdf

Maximum Yield UK | November / December 2011

Automation

Nation

by Isabelle Lemay, agr. and Mélissa Léveillé

Climate controller calibration for indoor gardening success In indoor gardening, the ultimate goal is always quality harvests with maximum yields; invested time and money must be profitable! A conscientious gardener will take care of measuring his harvests to determine the profit of his garden after each crop. How? By simply counting and classifying the fruits and flowers according to their size or to weigh the leaves or the harvested fruits. What’s important is to find a suitable method to quantify

Maximum Yield UK | November/ December 2011

the different parts of the plant in which we are interested. As one production varies from another, it is important to take note of the parameters used for each of them. This way, we better understand the crop’s evolution and it becomes possible to identify the ideal recipe to gain maximum benefit. In order to find that famous recipe and to repeat it again, it is necessary to work with precise instruments.

action is to adjust a measuring instrument against a standard measurement of which the precision is certain. In indoor gardening, an appropriate calibration of your climate controllers is essential because false readings bring inadequate actions Figure one: Mercury thermometer, psychometer and CO2 sensor calibration kit which in return at 1,000 ± 20 ppm. cause unwanted situations that affect the productivity. Calibration With such a chain reaction, it becomes In your indoor garden, the thermometer difficult to identify the true source of shows 24oC, the hygrometer reads 58 per the problem. cent and the CO2 (carbon dioxide) controller, 1,048 ppm (parts per million). So, When to calibrate you think your plants are comfortable Just as the majority of sensors are facand existing in the best conditions. But tory calibrated, it is recommended to now leaves are curling and some mildew verify the exactitude of the calibration has developed.Your harvest prospect at installation time and every crop start, looks disappointing, in other words, less particularly for CO2 sensors, which are quantity and less quality. What’s happenconsiderably more fragile and subject to ing? Since the beginning of the crop, an important reading variation. A simple you took good care of following every shock, in transportation or at the instalstep of your usual recipe, which every lation, is enough to make the sensor time produced good results. It could reading slip away from the true value. be that the measuring devices for the From our experience, we recommend temperature, humidity and CO2 concalibrating NDIR CO2 sensors before centration give false readings. What’s the each crop or every three months to offer problem? Could it be the calibration? your plants the best possible growing The calibration of measuring devices has conditions. Some CO2 controllers even the goal to obtain an exact value of what display a reminder message to calibrate it we wish to measure. The calibration’s at regular intervals.

Maximum Yield UK | November / December 2011

Automation Nation

“The calibration’s action is to adjust a measuring instrument against a standard measurement of which the precision is certain.” How to calibrate Calibration methods vary according to the controller and sensor type. for all calibration, the basic principle to remember is to use a reliable reference. We can think about a mercury thermometer for the temperature, a psychrometer for relative humidity or a calibration kit for CO2 sensors (figure one). Without a reliable reference value, we risk falsifying the reading even more from what it was originally. Among calibration methods, some are more effective while others are to be completely avoided.

Offset When a controller or sensor can’t be calibrated, which is often the case for temperature and relative humidity sensors, it is possible to validate its precision by comparing its reading to a reliable measuring device. Simply note the difference on a piece of paper and place it near the controller to remember adding or subtracting a given value to the displayed reading. Then, adjusting the controller’s set point to apply the corrected value will be needed. For example, in the case of a controller displaying two degrees more than the real value, it will be necessary to add two degrees to the set point to obtain the desired temperature. However, this method might become tedious and can be subject to errors. Fortunately, there are some electronic controllers that allow correction of their reading by adding or subtracting automatically a value to the controller’s reading (offset). This way, the controller displays a corrected reading and applies it to its programming!

The limits of a calibration with another device’s measurement Although practical, the calibration with another reference has its limits. Remember that scientific uncertainty analysis adds up errors from the measuring instruments. In other words, the calibration is affected by both controllers’ imprecision deviations. Let’s take for example a CO2 controller. With a precision of ± 75 ppm for the sensor to be calibrated and a similar ± 75 ppm reference controller, we would obtain on the newly calibrated controller readings within ± 150 ppm from the actual CO2 concentration; there’s the importance of having a reference as precise as possible. In the particular case of a CO2 sensor, the method by comparison also presents other inconveniences. In fact, we have to assure that the CO2 concentration 58

Maximum Yield UK | November/ December 2011

Figure two: The controller has been placed in a sealed bag to protect it against human breathing, a factor that significantly influences the sensor.

is as stable as possible during the whole calibration process, which is not an easy task in a non isolated environment. The simple fact of breathing (between 30,000 to 40,000 ppm) near the controller significantly influences the sensor! So which method should be adopted for this type of sensitive sensor that requires regular calibration?

Calibration kit for CO2 sensors

The ideal calibration method is to expose the sensor or the controller to a gas mix with a known and certified CO2

the ideal way is to calibrate the controller with a gas mix that has a concentration close to the one desired in the garden (around 1,000 ppm). Some retailers and manufacturers offer, at an affordable price, a calibration service using this precise and reliable method. According to the calibration number to make and frequency, it might be worthwhile for the gardener to get a calibration kit.

“The simple fact of breathing near the controller significantly influences the sensor!”

Why not calibrate CO2 sensors outdoors?

concentration. Some sensors have a built-in calibration circuit in which we vapourize a known concentration gas mix. Most of the horticultural controllers used in indoor gardening do not have such a circuit. We can then place the controller in a sealed bag to protect it against human breathing, remove the air from the bag and replace it with a known CO2 concentration mix (figure two). Then, just follow the user’s manual calibration instructions. Like every precision measurement device, we have to remember that a CO2 sensor will be inaccurate at its measurement scale limits, for example around zero and 5,000 ppm. To obtain a calibration as precise as possible,

For many years, CO2 controller manufacturers have recommended the outdoor calibration method, for want of anything better. This method suggests an average outdoor CO2 concentration from 350 to 400 ppm, which is never truly right at any location depending on the area’s different CO2 emitting sources. For example, vehicles reject approximately 20 per cent of their exhaust in CO2. Imagine the CO2 quantity rejected during rush hour in the cities, and this is without taking in consideration the CO2 rejected from factories. We can also think about those wood, fuel oil and gas heating systems. Depending on the time of the day, the outdoor real CO2 concentration in the air is between 350 and many thousands ppm. We also have to consider that in cold weather, the difference between the outdoor temperature and the garden’s temperature will falsify the calibration as the electronic circuit operates in different conditions. So it is better to avoid this method. With all aspects we just covered, you are now well informed on the need for precise climate factor readings in indoor gardening and the importance of calibration to get them right. And once your controller is well calibrated, it is still necessary to know well your plants’ needs in order to properly program it for maximum yields. MY Maximum Yield UK | November / December 2011

by Therese Cressman

Massive Attack Pests and disease get a dose oF organics

With a little bit of planning you can help cut down on pests and disease organically by planting natural repellants near problem plants. I have a few suggestions along with a few recipes using non-harsh ingredients that can help deter pests (and some disease)

Epson salts spray: Two ounces of salt per

Radishes: Plant near cucumbers

Mineral Oil Spray: Three parts oil per 100 parts water

Here’s a short and sweet recipe to help with pest control for indoor and outdoor gardens and houseplants.You can use this as a preventative spray as well as a bug and pest killer.

mealybugs, scaled insects and whitefly

Ingredients:

eight litres of water Benefits: Helps with black spot, mildew, wilt and rust

Benefits: Helps with aphids, codling moth, leaf roller,

Beer: Stale or mixed with molasses Benefits: Helps control slugs

Tomato leaf spray: Crush leaves and soak in water for a couple days, stain then spray

Benefits: Grasshopper and whitefly control

Soap spray: Two tablespoons of soap flakes dissolved in one litre of water. *Don’t use detergents

Benefits: Aphid control

Basil: Plant in pots and place around patio or deck Benefits: Repels flies and mosquitoes

Rosemary, Mint, Thyme: Plant near cabbage Benefits: Repels cabbage worms

Nasturtiums: Plant near cucumbers, melons and squashes Benefits: Repels squash bugs

Summer savory: Plant near beans Benefits: Repels bean beetles

Maximum Yield UK | November/ December 2011

Benefits: Repels cucumber beetles

1 cup Sunlight dish soap 1 tablespoon vegetable oil

Directions:

• Mix ingredients together then store in a plastic, airtight container. • When you’re ready to spray your plants, take one to two teaspoons of the concentrate and mix with a litre of water. Pour into a spray bottle. • Spray your plants making sure to get underneath the leaves as well as the flower buds and new shoots. • In a hot environment, repeat every third day (three applications over seven days). • In a warm to cool environment, spray once a week for three weeks.

Organic Insect Repellent

• Save onion skins, peels and ends then refrigerate in an empty margarine-sized tub or bag until the container is full. • Once you have enough, place the onion pieces in a pail and fill with warm water. Soak for a few days, up to a week. • After one week, strain the onion bits out and store the onion water in spray bottles. Bury the onion bits around plants that are prone to aphids, spiders and other pests. • Spray both houseplants and garden plants with the water to fight aphids and pests.

*You could also mix your garlic trimmings in with the onion pieces; bugs hate garlic too. MY

Maximum Yield UK | November / December 2011

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

IndustrY’s Latest

fRESH INDUSTRY NEWS AND ANNOUNCEMENTS, PLUS EXCLUSIVE GIVEWAYS FOR GROWERS

Atami’s B’cuzz Gets a 2011 Facelift

Atami entered the hydroponic market in 1997 as one of the first manufacturers of B’cuzz stimulators, which developed into a complete product range. Over the years the B’cuzz label underwent some small changes, but after 14 years Atami decided it was time to give the B’cuzz label a much needed makeover. It was time to redesign our B’cuzz labels for a more modern, fresh look that suits Atami’s brand and culture. Our refreshed B’cuzz range is now available in garden centres. It’s the same quality with a new look. Visit www.atami.com for more information.

Free Canna Tap With Five Litre CannaBoost Purchase

Starting November 1, 2011 when you purchase a five litre bottle of CannaBoost you will receive a free Canna spanner and tap*! The spanner can be used to open all of our five and 10 litre product bottles. The tap will help you measure the exact amounts of CannaBoost or any other Canna five or 10 litre product needed. Ask your local hydroponic shop about the spanner and tap when you purchase a five litre bottle of CannaBoost. *As long as the spanners and taps are in stock.

Make This Season Your Biggest Yet With These New Tools From Nutriculture

Get the right system for you. Get Nutriculture’s complete guide to hydroponic systems from your local grow shop. Get your grow started. Watch the assembly video on our website or in-store. Get massive yields. Visit our website for the hints and tips for optimum yields. Look out for Nutriculture QR codes in your local grow shop, which will link you directly to product information and videos. On the go? Visit our new mobile site for all you need to know including assembly videos, hints and tips. Web www.nutriculture.com Mobile m.nutriculture.com

Join Plagron on Facebook and Keep up With Our Latest News and Tips

Plagron has recently created a Facebook page at www.facebook.com/plagron. Become a fan to stay informed about the latest news and developments, our products and growing in general. Become a fan of Plagron by clicking on the “like” button on our page. All our updates will appear automatically on your home screen. If you have any questions don’t hesitate to contact our service desk: servicedesk@plagron.com or call 31 (0) 4956 31559. Pass it on: www.plagron.com/new

Maximum Yield UK | November/ December 2011

AutoPot Commercial Trials

AutoPot Watering Systems is pleased to announce they will be conducting a commercial trial at Valley Grown Nurseries beginning in December and running for two years. Valley Grown Nurseries is one of the UK’s most prestigious and respected nurseries. They grow over 250,000 pepper plants a year and supply the main supermarkets within the UK with peppers all year round. AutoPot will be establishing the trial using 200 easy2grow irrigation systems, for a total of 400 pots. Gary Taylor, owner of Valley Grown Nurseries, is one of the most respected and well known horticulturalists in the UK; both he and Jason Ralph Smith, the founder of AutoPot, will be overseeing the trial. The AutoPot systems require only gravity pressure from water tanks so there will be no need for timers, pumps or electricity, making this trial unique and truly innovative. The trial will be monitored using time-lapse photography and live video streaming, which will be available to view at www.autopot.co.uk

New Packaging for the Bio Boosters

General Hydroponics Europe’s Bio Roots, Bio Bloom and Bio Protect have been recognized as the best rooting, flowering and immunity boosters for a decade due to their high concentration and efficiency. For their 10th anniversary, with the help of the excellent designers at General Hydroponics, we decided to redesign the packaging. Only the look has changed, though. What’s in the bottle remains the same. Nothing could make us modify our Bio Booster formulas. Bio Boosters are still sold in 30 and 60 millilitre containers, and due to their success, we also offer them today in 250 millilitres, 500 millilitres and one litre bottles. Visit www.eurohydro.com for more information. GHE-2011-VERT.pdf

14/12/10

10:20

New Packaging, New Possiblities From Plagron

As your partner for better growth, blooms and yield, Plagron is introducing new packaging. As of December 2011 in grow shops around Europe, the old, familiar packaging will be replaced by our fresh, new product line. The whole operation consisted of over 100 facings in five product categories, namely: 100 per cent Bio, 100 per cent Terra, 100 per cent Coco, 100 per cent Hydro and Plagron’s additive line, Universal. In design as well as composition the total assortment will help growers get better results. The information and instructions on the packaging is easier to understand, making the products easier to use. Plagron wants to be the brand that growers use to get the best possible yields. More information can be found at www.plagron.com

Discover the secrets of CannaBoost

CannaBoost is one of the most popular boosters on the market. In addition to all the positive feedback we receive about CannaBoost, we also receive a lot of questions. Canna is available to answer all your questions regarding CannaBoost on our website at www.canna-uk.com. Information on the website will be shown in sections under something to read, something to watch and something to play. While there you can also enter to win great CannaBoost prizes! Find out all the secrets of CannaBoost, by scanning the QR code or surf to www.canna-uk.com

Maximum Yield UK | November / December 2011

PRODUCT SPOTLIGHT Continued from page 19

AutoPot’s 1Pot Module Watering System The AutoPot 1Pot Module offers a unique and extremely simple solution to providing your plants with everything they need. The 1Pot Module requires no electricity, timers or pumps, just gravity pressure from a waterbutt or tank. Once set up the AQUAvalve within the tray takes over. Once set the pH and EC remain constant in your reservoir. With the 1Pot Module hundreds of pots can be linked. The pots and trays can be easily moved and spaced if the plants grow too large. The 1Pot Module requires minimal input, and is therefore extremely low maintenance. It can be left unattended for weeks at a time whilst still producing outstanding results. AutoPot is available now from authorized retailer distributors.

Cyclone ONA Fan - High Efficiency Airflow Design a Win-Win for Odour Control Odorchem Manufacturing Corp. is pleased to introduce our new ONA Cyclone Fan. Unlike its predecessor, the ONA Storm Fan, our new highefficiency airflow design draws air in a cyclonic motion from above the fan propelling it directly into the pail of gel providing a 30 per cent increase of ONA into the air. ONA Cyclone provides enough air circulation to neutralize odours in a room up to a maximum of 465 square metres. Visit your favourite hydro shop for more information.

New Plant Magic Evolution Plant Magic Evolution significantly speeds up the vegetative stage, promoting overall growth and increasing the number of healthy new shoots produced, gearing the plant up for bountiful fruits and flowers. The unique formula provides an abundance of benefits: improved photosynthesis leading to rapid vertical growth, healthier plants, more fruit sets (leading to better yields) and improved root structure. Evolution can be used in any system. Use as a foliar spray once a week up until day 14 of the flowering cycle. Evolution is ready to use; no dilution required. Nutriculture is an exclusive distributor for Plant Magic Plus. Visit your favourite hydro shop for more information.

Drip Potz Systems Drip Potz are the most versatile hydroponic system available, allowing you to grow in round or square pots, Root Pouch or Air Pots and the medium of your choice. These top feed drip systems deliver your nutrient solution at minute timed intervals through your irrigation delivery dripper system. The excess nutrient solution can run off from the pots and into the specially moulded saucers, which are fitted with filter screens to prevent any debris entering and blocking the drain pipes. The excess solution can then run freely into the Header Return Potz, which are fitted with a float switch and pump to recirculate the solution back into the main tank, or if desired it can be run-to-waste into another tank or nearby drain. Visit your favourite indoor gardening shop for more information.

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

TALKING SHOP

From left: Scott Gregory (sales assistant), Ryan Purcell (sales assistant), Rob Depledge (director) and Jamie Sloane (director).

AT A GLANCE Store Name: Acorn Horticulture Owners: Jamie Sloane and Rob Depledge Location: Sheffield, South Yorkshire, United Kingdom Phone: +44 (0) 114 2458581 Web: www.acornhorticulture.co.uk E-mail: sales@acornhorticulture.co.uk Motto: “Grow with us.”

After being friends for years, it seemed Jamie explains: “We started out with a like a perfect idea for Rob Depledge derelict building—7,000 square feet—and and Jamie Sloane to go on to be renovated it bit by bit over nine months business partners. Rob worked in the until we had exactly what we wanted in steel industry and Jamie in the banka store: a huge display space (3,200 square ing profession before they decided to feet), a large counter area, massive wareventure into the world of hydroponics house and stock potential, private parking and horticulture when they were both and loading facilities, and most of all the in their early 30s. great location—just minutes from JuncJamie and Rob’s interest in horticultion 35 of the M1 near Sheffield.” ture sprouted roots when they were “We built up our stock to a point where young, with them both helping mum we now carry over 3,000 lines from every and dad in the greenhouse—whether it major manufacturer and can offer next was potting up geraniums or cleaning day availability on over 95 per cent of the greenhouse down at the end of the them. Not only that, but we now buy in season—and the green-fingered theme much larger volumes, which allows us to continued for Jamie as he took up land- negotiate better prices from our suppliscape gardening later in his career. ers—deals we pass onto our customers!” “We were always destined to work Jamie is pretty confident that their busiin the hydroponics and horticulture ness is just going to keep on expanding. industry,” Rob tells us.“We love dealing “We are always on the lookout for new with the public, seeing them grow and talent, so if you’re experienced in the benefit from the investments they make hydro industry and would like to work in their growing environments and their with us then give us a call.” knowledge.We had the opportunity to launch “We like to think that we do things our own business in differently from most hydro stores November of 2009.”

and that’s what many of our customers tell us.”

Maximum Yield UK | November/ December 2011 UK | November/

“We love dealing with the public, seeing them grow and benefit from the investments they make in their growing environments and their knowledge.”

Rob thinks he knows what sets them apart from other grow shops in the area. “We like to think that we do things differently from most hydro stores and that’s what many of our customers tell us. They like our ‘no nonsense’ approach to business, with good, friendly, honest advice, the wide ranges and high-end quality brands we stock together with our ‘seven-days-and-open-late-policy’ and our great location.” Jamie is convinced that a big part of their success is also due to the great rapport the two partners have built with people in their industry. “We have built strong working relationships with our suppliers and have made some great contacts that have really helped us— and they continue to support us as we move forward with our business. We are always looking for the next innovation in hydroponics and we work closely with suppliers and manufacturers to ensure we are among the first to bring new products to market.” Rob adds, “A great example is the new range of Gavita lighting equipment, which comes from commercial horticulture in Holland and is distributed in the UK by the guys at Direct Gardening Supplies. The 600 watt Pro Full Fixture unit is one of the most exciting things to come to the hydro market and produces results that really do have to be seen to be believed.”

But the boys are not content with their present success—they’ve got big plans for the future. “As well as our successful retail business,” Jamie says, “we have started to develop a small interest in the commercial market in the form of a joint venture on crop production with a farm in Ireland, and we’re also doing commercial and domestic irrigation contracts. And recently we’ve had a number of customers who specialise in growing carnivorous plants, like giant fly traps. This part of our business has been so successful we are looking to carry a full range of these specialist plants for sale in the store later this year.” Rob is sure they’re on the right track. “As of late 2011 we have a new e-commerce website going live. There will also be a wide range of support and downloadable advice available, so please visit the new site at www.acornhorticulture.com. And it doesn’t stop there, as we’ve got plans to secure premises for a new store planned for Yorkshire—opening in mid2012—so keep your eyes out as Acorn could be coming to a location near you.” The two partners try to keep their karma clean as they move forward, figuring that they should make a positive contribution to the place that supports

them. “We like to give a little bit back to the local community where we can,” Jamie explains, “and we sponsor two of our local football teams. We’re also looking forward to working together with our local primary school for the next term, with the idea of putting growing systems and nutrients together with the expert knowledge they’ll need in order to get the kids growing.” Rob takes a moment to sum up how they feel about their recent success: “Moving into this industry has been the best thing we’ve ever done, but if there was one piece of advice I could give, it would be to not underestimate the sheer hard work involved to get any new business off the ground, let alone a hydro store in an already competitive marketplace! If you are to work for yourself and be successful in this industry you must be determined and focused and—most of all—always remember to keep the customer at the heart of everything you do.” MY

Maximum Yield UK | November / December 2011 UK | November

COMING UP IN January-February

DO YOU KNOW?

1. 2.

Photosynthesis takes place mainly in young maturing leaves. Older leaves and those partly shaded photosynthesize less, thus drawing on the nutrition from young maturing leaves for their survival. Upon the initial discovery of Azospirillum, it gained praise for its ability to produce a form of nitrogen that plants can easily use.

A tomato plant carrying a substantial fruit load under high atmospheric demand conditions will require at least one litre of water during the daylight hours.

4. 5.

Chloramines are much more persistent than chlorine and take a lot longer to dissipate from treated water. It is recommended that growers calibrate NDIR CO2 sensors before each crop or every three months to offer your plants the best possible growing conditions.

The temperature of a plasma found inside a star or fusion reactor can reach millions of degrees.

A plant may become deficient in phosphorous if the soil or soilless medium remains too wet for too long, which can occur in hydroponics if the water is not properly aerated.

Plant stress can be minimised by conducting major pruning in stages—allow plants to rest for a week or so between prunes.

The presence of even a low population of disease organisms in a nutrient solution will significantly impact a plant, reducing root function and possibly resulting in plant death.

10.

Clean and Green – Hydroponic Hygiene The warm and moist environment that is ideal for plants in an indoor garden is also ideal for a host of nasty life forms that we don’t want in our gardens. In keeping the grow space “clean and green” proper hygiene and regular maintenance can go a long way.

Talking Shop With… Get to know your local hydro shop. We could feature your favourite grow gurus in the next issue. Recommend your favorite shop to be featured in Maximum Yield UK by e-mailing editor@maximumyield.com Nutes, lights, environmental control, exclusive UK contests, industry’s latest, more!

www.maximumyield.com

Research studies have reported that chloramines in hydroponic nutrient solutions can cause growth inhibition and root browning in susceptible plants.

Maximum Yield UK (January/February) will be available January 1 for FREE at selected indoor gardening retail stores across the UK and on maximumyield.com

The simple fact of breathing (between 30,000 to 40,000 ppm) near an environmental controller significantly influences the sensor.

Subscriptions are available at maximumyield.com/subscriptions.php

11. 70

Cloning Wars Dense Matrix LED technology battles its way into the lucrative world of cloning. What is the technology capable, what can it offer hobby growers and is the upgrade worth it?

Maximum Yield UK | November/ December 2011

Maximum Yield UK | November / December 2011

MAX-MART

Maximum Yield UK | November/ December 2011