Maximum Yield UK July/Aug 2011 by Maximum Yield

UK July - August 2011

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Climate Control

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Root Zone Chilling: Handling the Heat Plant Nutrient Elements 1: Macronutrients www.maximumyield.com

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Maximum Yield UK | July / August 2011

CONTENTS july / august 2011 FEATURES 20

Root Zone Chilling: Handling the Heat

For Peat’s Sake: The Peat Problem and Alternatives

Plant Nutrient Elements - Part 1: The Macronutrients

Plants and Sounds

Climate Control

The Beet Goes On

Pollination Problems for Indoor Vegetable Gardeners

by Dr. Lynette Morgan by Michael Bloch

by Philip McIntosh

by Evan Folds

by Réal Adam & Isabelle Lemay

by Clair Schwan

DEPARTMENTS 28

From the Editor

Letters to the Editor

MaximumYield.com

Simon Says

MAX Facts

Product Spotlight

Talking Shop

Do You Know?

Coming up in September/October

Max Mart

40 Maximum Yield UK | July / August 2011

FROM THE editor

jessica raymond

Thank you to all our retailers and advertisers for contributing your industry predictions in our UK 10th Anniversary issue.The response was overwhelming and we are ready to fulfill our promise to you for the next 10 plus years to continue to jam every issue with the industry’s best products, the most up-to-date growing techniques and the latest local and global news. This issue we share with you some of the most important factors that indoor growers need to be aware of in the garden such as: climate control and pH, pollination, root health, nutrition, eco mediums and more.Whether you’re a beginner hobbyist or an aficionado, each page in this issue will provide you with some great tips for producing your best crops ever this summer. If after devouring this issue from start to finish you still want more, visit MaximumYield.com and check out our archive for hundreds of informative articles covering every topic imaginable related to modern gardening practices, or you can e-mail your questions to Simon@maximumyield.com for expert answers to your specific questions.

Jessica Raymond, Editor editor@maximumyield.com

letters to the editor Win Big…Grow Big

This is awesome, plus today is my birthday! Thanks for having such a great contest. Namaste. - Jessica Potter I can’t wait to try out my new grow pot. Your magazine is great and you have very informative articles. I look forward to reading your upcoming issues. I always learn something new. Keep up the good work and thanks for having this contest and giving out some great free stuff. - Paul Garces I wanted to thank Maximum Yield for the Geo Humus soil conditioner that I received as part of the Win Big...Grow Big contest. I have already put it to good use. - Alfredo Cardoch And you can win too. Visit http://maximumyield.com/contests.php and enter by August 15 for your chance to win the latest grow gear.

It’s All About Air

Studious Hydroponic Enthusiast

Great magazine! I want to grow strawberries using an aeroponic system and trust you to guide me to the information we need. Online archives, online searches, books—wherever I need to go, please help. Thanks in advance.

I am interested in any and all literature that you have on hydroponics and getting started in hydroponics.

John Gavlick

Thank You Leah Larsen

MaximumYield magazines are a wealth of knowledge on all things hydroponics, indoor gardening and organics. I encourage you to pick up the latest issue of MaximumYield at your local indoor gardening shop for free (to page 50 for a selection of the best retail shops in the UK). All of our publications are available for free online at www.maximumyield.com, including 12+ years of articles related to modern gardening topics. I also invite you to follow us on Twitter (twitter.com/Max_Yield) and on Facebook (Facebook.com/MaximumYield).

Maximum Yield UK | July / August 2011

The following articles might help in your endeavor.They can all be found on maximumyield.com under our author or article archive. “Berry Bonanza: Growing Indoor Strawberries” by Dr. Lynette Morgan “Aeroponic Technology Versus Premium Organic Soil Cultivation” by Lee McCall “Water as a Substrate: Aeroponics and Aero-Hydroponics” by Noucetta Kehdi “Advance Aeroponics” by Joshua Serpa Good luck, and let us know how you make out. We Want To Hear From You! Write Us At: Maximum Yield Publications Inc. 2339A Delinea Place, Nanaimo, BC Canada V9T 5L9 or editor@maximumyield.com

Maximum Yield UK | July / August 2011

Coming up on the Web Upcoming Events

8th Annual San Francisco Expo 2011 (SFIGE11) Maximum Yield’s 2011 Indoor Gardening Expo Tour will once again be making a stop in San Francisco, July 16 to 17 at the Fort Mason Center. This event offers education and entertainment rolled into one. We look forward to seeing you all in San Fran in just over one month. Countdown with us to this world-class event on indoorgardenexpo.com

Featured Articles

I N D O O R

G A R D E N I N G

VOLUME 11 – NUMBER 2 July/August 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

Old Fashioned Crops are Making Comeback

With a renewed interest in the culinary arts and gardening in general, we are seeing a resurgence of some old crop favourites and finding many of these are well suited to indoor and hydroponic production.

Companion Planting in Hydroponics

Companion planting outdoors is a popular gardening trend, but in a hydroponic garden, it’s a whole different game. Pay attention to these fresh tips and success and great yields will surely result.

The Great Organic Hydroponic Debate

Find out what’s organic and what’s not and how these two concepts—hydroponics and organics—can work together under today’s certification standards.

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 Christina Indseth- christina@maximumyield.com Ashley Heppell - ashley@maximumyield.com PRODUCTION & DESIGN ads@ads.maximumyield.com Mike Linden - mike@maximumyield.com Daniel Peters - daniel@maximumyield.com Jenn Duong - jennifer@maximumyield.com Tina Skujins - Tina@maximumyield.com ACCOUNTING - Lee Anne Veres leeanne@maximumyield.com

[insert small image of QR code] Connect to MaximumYield.com instantly from your Smartphone with our Quick Response (QR) Code, found on the cover of every issue of Maximum Yield. Now you can access the best products, the most in-depth articles and information and the latest news, at high speeds. Simply download the QR Code Reader software compatible with your Smartphone, scan the QR Code and your phone’s browser will automatically launch, redirecting you to www.maximumyield.com. It’s that simple!

Connect with Maximum Yield

maximumyield.com • facebook.com/MaximumYield • indoorgardeningexpo.com • twitter.com/Max_Yield

Tell us what you think at editor@maximumyield.com. We’d love to hear from you.

contributors Clair Schwan is an experienced gardener and builder of homemade greenhouses. For detailed discussion and pictures of his greenhouses, visit www.frugal-living-freedom.com. See his advice and counsel on a range of vegetable gardening and greenhouse topics at http://www.vegetablegardening-and-greenhouses.com

Michael Bloch is the owner and

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.

Evan Folds is president of Progressive Gardens, a natural approach land care company, and Progress Earth (www.progressearth. com). With a degree in biology and religion, Evan’s interests include making sense of food production and bringing awareness to such topics as empty food, municipal water fluoridation and spiritual intolerance.

Maximum Yield UK | July / August 2011

editor of GreenLivingTips.com, an online resource powered by renewable energy. The site offers a wide variety of earth friendly tips, green guides, advice and environment-related news to help consumers and businesses reduce costs, consumption and environmental impact.

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.

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.

UK DISTRIBUTION Growth Technology Future Harvest Developments Europe Nutriculture UK 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 R & M Supply Tradewinds AUSTRALIAN DISTRIBUTION Dome Garden Supply Futchatec Growth Technology Holland Forge House N Garden Hydraspher

Maximum Yield UK | July / August 2011

SIMON says

Hey Simon, I have a very simple question that has me and many other growers confused. I grow in a general purpose peat-based growing medium with vermiculite and perlite in buckets and I feed from the top. My question relates to pH. I have heard that peat-based grow mediums are soilless, and therefore should be watered/fed at 5.8 to 6.1 pH. I have also heard that these mediums should be treated like soil and watered/fed at 6.4 to 6.8 pH. Other people have said that they water/feed at 6.1 to 6.2 pH and certain fertilizer companies instruct watering/feeding at 6.3 pH. I’ve been looking on different forums on the Internet, and it seems to be an area that really confuses a lot of people. I’ve noticed that the medium I use has a pH of anywhere between 5.3 to 5.8, so with this in mind, what should the pH of my water be? What runoff pH should I be looking for? What pH should I be watering/feeding with using peat-based products? Jon The use of sphagnum peat moss is prevalent in both professional and hobby gardens alike. This type of peat has some very good characteristics but there is no perfect media. After being harvested and dried pure peat would have a low pH, somewhere between 3.8 to 4.9 depending on the source bog and material. A lot of peat suppliers can, and do, ship straight peat but most of what they ship out are blended products. The product you are referring to specifically puts a variety of ingredients into the compressed bales and loose bags to amend the peat. To adjust the pH, most producers use dolomite lime to buffer the peat medium to somewhere between 5.5 to 6.0 (although individual bags vary). This buffering can last up to three months depending on the environmental conditions and irrigation methods. Remember that the peat will have a much higher buffering capacity than the water, which can be easily adjusted. This means to adjust pH of the peat with irrigation water would be exceptionally difficult. Your fertilizer solution is best buffered at 5.5 to 6.5 as a general rule. There could be a pH outside that range that works well for your crop, so experiment when possible. To assess a medium’s pH without an analytical soil analysis you can monitor the leachate, which drains from the bottom of your containers. If you find the leachate pH is lower than your water supply you can try mixing calcium into the top layer of the soil.You can also attempt to follow a more

Maximum Yield UK | July / August 2011

complicated biochemical process if you know the composition of the fertilizer you are using. Ammonium nitrogen (NH4) will result in a drop in the medium’s pH while Nitrate nitrogen (NO3) can raise the medium’s pH due to interactions in the rhizosphere. If you intend to reuse your peat be sure to rinse thoroughly to remove residual nutrients before checking the pH. If the pH has drifted below 5.5 be sure to add more dolomite to ensure that you start with a higher buffering capacity. Bacterial-based organic supplements such as worm casting and compost should have a higher initial pH and can be excellent amendments to a peat base. Using coir can also be useful to moderate the low pH of peat by blending in material with a higher pH. Be cautious because this will also affect the overall structure and moisture release curve of your medium. MY Do you have a question for Simon? Send it to simon@maximumyield.com with the words “Simon Says” in the subject line, and your answer will be printed in an upcoming edition.

Maximum Yield UK | July / August 2011

MAX

facts

hydroponic news, tips and trivia from around the world

Fascinating Food Stories From the British Library The UK’s national library and one of the world’s largest research libraries, the “BL,” features an incredible “Food Stories” section, an animated tour of the U.K.’s food culture over the last century. The interviews and related materials in the stories explore the ways in which food relates to identity, cultural diversity, the environment, technology, farming, shopping, travel and many other aspects of life. (Source: www.treehugger.com)

Plants and Pets Our gardens are places where our pets spend much of their time, but often the two do not go together. There are hundreds of commonly grown plants that are highly toxic to dogs and cats. For example, Macadamia nuts, although delicious to us, are toxic to dogs. Check out these links: Plants toxic to dogs (www.dog-first-aid-101.com) Plants poisonous to cats (www.cat-world.com.au) (Source: www.warmearth.com.au)

Meet the Metal Farmer How often do you encounter a farmer sporting cargos and a t-shirt, spraying neem fertilizer, all the while head banging to Iron Maiden? Take a trip to Pritham D’Souza’s farm in Kinya, Karnataka (India), and you are bound to encounter this very avatar of the ‘metal farmer.’ What makes this young agriculturist even more interesting is that he employs simplified hydroponics. For now, the hydroponics set-up is on a small scale but judging from the great feedback, expansion is in the pipeline Pritham is one hard-working farmer, who wakes up at 6 a.m. and goes to bed at 2 a.m. Pritham acquired his father’s passion for farming, and shuttles between Bengaluru and Mangalore on work. “Hydroponics has existed for 80 years now. But most Indian agriculturists are sceptical of adopting it, since it’s too ‘Western’ for their tastes.” (Source: www.deccanchronicle.com)

Maximum Yield UK | July / August 2011

MAX

facts

hydroponic news, tips and trivia from around the world

Vertical Garden to Tower Over Chelsea Flower Show A nine metre tall food garden (skyfarm) was constructed for the 2011 Chelsea Flower Show in London. One wall of the steel-frame structure is entirely plants, the other entirely solar photovoltaic panels. The panels power the water pumps that push water from a borehole around the hydroponic growing system. Inside the tower, along with the stairs are greenhouse areas for propagation, and a compost chute. Everything in the garden is edible, even the trees: the vertically trimmed lime trees have flowers that can make an herbal tea, while the mulberry trees give a crunchy berry. The garden illustrates the hundreds of edible plants in the world, including many unusual varieties like Stevia rebaudiana, a sweet-tasting sugar substitute. (Source: www.guardian.co.uk)

Finding a Polyamine Way to Extend Tomato Shelf Life Tomatoes spend so much time on shelves and in refrigerators that an estimated 20 per cent are lost to spoilage. (Source: www.ars.usda.gov)

Five Urban Farming Ideas for Your Own Backyard Let’s take a look at some growing trends in urban farming. Backyard gardens: Why settle for a boring lawn or shrubbery when you can walk a few steps to your backyard into an edible forest of fresh onions, chard, spinach, lettuce and squash? Worms: Vericomposting is becoming a popular trend for creating your own rich compost. Earthworms break down the soil, helping it breath and stay loose so plants’ roots can grow better. Bees: Beekeeping has been gaining popularity in urban areas. Urbanites have turned keeping hives into a profit, selling fresh local honey to the community. Chickens: Chickens can be fed just about any old scrap from the kitchen table, and the more variety in their diet, the more nutritious the eggs they lay. Aquaculture: Considering the sad state of our oceans and declining and poisoned fish populations, it makes sense to take a shot at farming your own fish. (Source: http://ecosalon.com)

Maximum Yield UK | July / August 2011

Rabbit Battery Farms Could Return to UK

Just a year or two ago seed bombs used in guerrilla gardening were a quaint homegrown experience. Now a UK company—Seedboms—is selling ready-made seed bombs for cheap. Produced in Scotland, they are handmade from locally reclaimed and recycled materials such as post-consumer paper and used egg boxes. They also contain organic peat-free compost, organic fertilizer and a selection of easy to grow flower seeds. They break down over time and biodegrade into the environment leaving only flowers behind. Each bomb contains a different kind of seed. There are sunflower bombs, nasturtiums, native wildflowers and cornfield flowers.

The intensive rabbit battery farms, which would be the first for rabbits in the country in 15 years, have been proposed at sites from Nottinghamshire to Cornwall. Previous farms closed down, undercut by foreign rabbit farms with lower welfare standards. What has changed is the ability to produce lower cost feed via a hydroponic pond in which barley grass would be grown, providing 60 per cent of the rabbits’ diet.

(Source: www.Treehugger.com)

(Source: www.guardian.co.uk)

Seed Bomb Business

Maximum Yield UK | July / August 2011

PRODUCT spotlight

Ask for them at your local indoor gardening store.

YOUR GUIDE TO THIS ISSUE’S HOTTEST ITEMS Boldtbags Large Wash Bag The Boldtbags Large Wash Bag is new and improved with a snap buckle closure to keep the zipper locked in place. The Large Wash Bag is made of Swiss grade quality mesh with reinforced stitching at the seams and a military grade zipper and buckle. The mesh screen has been measured to the absolute micron and heat stamped to prevent fluctuation. Boldtbags Large Wash Bag can be used to help speed up the agitation process or to wash delicate laundry. It is the most durable bag on the market and comes with a two year warranty. Visit your local indoor gardening shop for more information.

Wilma Big - Bigger is Better Wilma Big provides the flexibility of growing in pots with the accurate feeding and increased yields of active hydroponics, and it now features additional space so you can grower bigger plants and achieve higher yields. The Wilma Big is available in four pots, eight pots and nine pots. The combination of massive 18 litre pots with the accurate feeding of active hydroponics means more root mass, greater nutrient uptake and increased yields. Bigger pots and wider pot spacing means plenty of room to grow big. Grow in any medium— clay, coco, soil and rockwool—and set feedings on a timer to suit the life stage of your plants. Wilma big is tailor made for tent growers. For more information visit a hydroponics shop near you.

Hotbox Heatwave Bench Heating System The Hotbox Heatwave is a made-to-measure bench heating system that encourages germination, propagation and growth of seedlings and cuttings by delivering constant, uniform heat to the base of seed trays and plant pots. The Hotbox Heatwave is easy to install, energy efficient, durable and flexible. It provides optimum growing temperature that seedlings and cuttings need to survive and thrive. Ask your local retailer to carry the new Hotbox Heatwave bench heating system today.

Phat Filters 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. Aluminium 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. All these reasons and more make Genuine Phat Filters the best choice on the market. Available now at your local hydro shop. Phat is a registered mark of International Growers Supply. 16

Maximum Yield UK | July / August 2011

PRODUCT spotlight

Your guide to this issue’s hottest items.

Clonebox View The Clonebox View incorporates all the great features of the standard Clonebox but now includes two large viewing windows in the front doors (each window measures 49 centimetres wide by 74 centimetres high and they can be light-tight sealed). Now you can check the condition of your precious plants, as often as you need, without having to disturb the sensitive climate zone. The Clonebox can be transformed into a motherplant box by simply removing the grids and it has an adjustable two shelving system in case extra space is needed. Rugged, high quality materials ensure a long life and all parts are replaceable. The additional flooring is heat-sealed and water resistant. The Clonebox View also features inlet and outlet tubes and ventilation windows. Ask for the Clonebox View at your favourite indoor gardening shop.

Organic Air Charcoal Fiber and HEPA Filters Organic Air Charcoal Fiber and HEPA Filters are lightweight, shippable, washable and perfectly suited for any greenhouse. Organic Air Charcoal Fiber Filters consist of high quality charcoal fiber mesh with zillions of micro-pores for optimal adsorption of nasty odours. Our HEPA intake filter keeps your grow room 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; a highly effective way to eliminate unwanted containments. Both filters are pleated for a doubling of surface area and utilize a dual inverted nose cone for maximal air flow. Available now at your local hydro shop.

Plagron All-mix - Now Available in 25 Litre Bags Plagron All-mix is an abundantly fertilized biological soil mixture perfect for the entire grow cycle. The various types of special high quality peat are enriched with worm castings, biological fertilizer and perlite to guarantee lightness and an oxygen level of unequaled quality. Plagron All-mix ensures healthy growth and maximum resistance to disease and fungal attack. The very fine structure of Plagron All-mix is exceptionally suitable for container gardening. For six weeks only watering is enough. After this period, extra nutrients can lead to better results. For a second grow cycle upgrade your soil with Bio-Supermix. Especially for hobby growers, Plagron All-mix is now available in 25 litre bags. Visit your favourite indoor gardening shop for more details.

Plant Magic Plus Granules Plant Magic Plus Granules is a granular inoculant made up of Mycorrhizal fungi, bio-stimulants and over 20 strains of beneficial micro-organisms. All these work to create an abundance of beneficial micro life within the soil. Granules promoted root growth (up to 700 per cent increase in mass), provide improved nutrient availability and uptake, and reduce the risk of pathogens and other undesirable organisms. This is a must have product for anyone growing in coco or soil. Works exceedingly well in Plant Magic Plus Soil Supreme growing medium. Available in 350 and 700 gram tubs at your favourite indoor gardening shop.

Maximum Yield UK | July / August 2011

Nutriculture’s Best Selling Hydro Range Just Got Better Nutriculture is proud to unveil the GT150 NFT GroTank. At just 15 centimetres tall, the GT150 features an ultra-low level nutrient reservoir. Tailor-made for tent growers, it is designed to fit small growing areas. It is easy to set up allowing growers to manage just one tank for up to 25 plants. An adjustable delivery system allows growers to place the pump on either side of the reservoir. Now available in the UK at your favourite indoor gardening shop.

HOMEbox Twin The HOMEbox Twin comes with two separate chambers that allow you to create two independent climates or have different light cycles and combines the advantages of the classic HOMEbox and the Clonebox. It comes with a very stable shelf to place propagators and equipment with a holding capacity of 40 kilograms. Both chambers are light-tight with separate intakes and exhausts. The new door concept makes access easier and assembling and dismantling can be done without tools and by one person. The HOMEbox Twin is 120 by 80 by 200 centimetres and takes up 1.9 square metres of floor space. Ask your local indoor gardening retailer to carry the new HOMEbox Twin.

Titan Controls® Helios 15™ ETL Listed 8 Light Controller With Timer Sunlight Supply®, Inc. is pleased to announce the release of the new Helios 15™ - eight light controller with timer from Titan Controls®. This ETL-listed controller is acceptable for use in commercial applications. The Helios 15 features two premium quality Siemens brand relays, a durable powder coated steel chassis, a German made ‘on-board’ 24 hour timer and NEMA 6-15R UL-listed power outlets. Controlling up to eight 1,000 watt lights at 240 volts has never been easier. Visit your local hydro shop for more information. Continues on page 46

Maximum Yield UK | July / August 2011

Root Zone

Chilling Handling the Heat

Is heat a problem in your indoor garden? Handle it with this advice so your plants can be at the top of their game. by Dr. Lynette Morgan

Heat loading in indoor hydroponic gardens is a common problem. The combination of high intensity lighting, small enclosed spaces, limited air exchange and sweltering summers all take their toll on plants. Small volumes of recirculating nutrient and restricted growing containers also contribute to heat buildup in the root zone, often to the point where roots can cook without the grower even being aware of the problem. A hot environment is hard to handle, often rather expensive to keep cool, and if combined with high humidity, the tropical conditions have some nasty consequences for plant growth and development. However, hydroponic systems can offer some significant advantages when it comes to a little manipulation of a plant’s physiology to boost yields and keep crops happy. Root zone temperature strongly affects shoot growth. In fact root zone temperatures play more of a role in growth and development than that of the air surrounding the plant. This is because the root tissue sends numerous ‘non hydraulic’ messages to the shoot, which influence the way the shoot responds to the environment. So with many plant functions under the control of what goes on down in the roots, temperature in the root zone becomes an extremely important factor to be keeping an eye on.

Maximum Yield UK | July / August 2011

Ignorance is not bliss Many of us have probably seen the effects of high air temperatures of crops—wilting, reductions in growth, tip burn, premature bolting, loss of chlorophyll (leaves going pale and yellow), flower and fruit let drop, overall losses in yield and increases in root disease pathogens such as pythium that prey on stressed root tissue. At high temperatures, plant tissue has a rapidly increased rate of respiration that burns up assimilate produced during photosynthesis, leaving much less for growth and development. While most growers keep a regular check on the air temperature surrounding their plants and aim to keep this within an ideal range for the species being grown, few realize the potential of root zone temperature control. Nutrient temperature buildup can be surprisingly fast and become excessive under hot lights and in systems with very limited root zones, so regular root zone temperature checks are a good idea. Research has shown that even a short duration, less than 30 minutes of root zone heat buildup, can have a very negative effect on many crops, which can not be compensated by having a low daily temperature

Showing the impressive root structure of aeroponic production.

average. Just a few minutes a day of root zone temperatures over 30°C have been shown to retard the growth of some heat sensitive crops such as lettuce and parsley. Root zone temperature physiology It seems that chilling in the root zone via the nutrient solution affects the plant’s physiology in a number of different ways, which allows the aerial portion of the plant to withstand higher than optimal temperatures. Firstly, we know a cooler nutrient solution holds more dissolved oxygen for root uptake, so that oxygen starvation is likely to be far less of problem than it would be with a warm nutrient. Secondly, cooling of the roots to well below ambient air temperatures seems to allow higher assimilation rates by reducing both photo inhibition and stomatal closure that typically occur once the plant becomes temperature stressed. What is even more interesting is that the positive effects of nutrient chilling seem to be largely the result of changes in the production of plant growth hormones abcissic acid (ABA) and cytokinins that control a range of plant responses. Cytokinins are mainly synthesized in roots and any environmental stress in this tissue, such as high temperature, results in a shortage of this hormone being sent up to the shoots.Very low cytokinin concentrations in the roots of even warm season crops have been found after only five days at -12 to 38°C suggesting that the response of cytokinin deficiency to high temperatures is very rapid. Cytokinins are important as they stimulate cell division, cell enlargement, chloroplast formation, synthesis of chlorophylls and proteins and in general, drive plant growth and development. The small leaf area, stunted growth and

leaf yellowing often seen in heat stressed plants may be at least particularly attributable to a reduction in cytokinin synthesis in the roots. ABA is known as a stress hormone and has been found to increase in leaves when roots are exposed to high temperatures. ABA is inhibitory to growth and results in stomatal closure and the reduction in photosynthesis that results as the plant starts to shut down. Tricking plants into handling the heat Apart from keeping a close check on root zone temperatures to make sure they are not over heating and cooking the roots, there is a well proven technique that can be used to fool the physiology of many plants into handling higher then optimal air temperatures. Root zone chilling of the hydroponic nutrient solution is a technique being used commercially by many growers in warm or tropical climates, most often with cool season crops such as butterhead lettuce, herbs and other vegetables. In Singapore NFT, aeroponic and deep flow culture systems are utilized with extensive nutrient chilling to grow butterhead and Romaine lettuce, crops that otherwise do not grow or yield well at ambient air temperatures. Chilling the nutrient solution down to as low as 16 to 18°C, allows the cool season vegetables to crop well at ambient air temperatures that are often well above optimal for these crops (28 to 36°C). Without nutrient chilling, the root zone usually warms to the level of the air and this gives numerous growth problems including slow growth, lack of heart formation, bolting, tip burn

Maximum Yield UK | July / August 2011

Root Zone Chilling

Lettuce being grown in a deep flow system with chilled nutrient under tropical conditions.

and low marketable yields. Other researchers have reported that nutrient chilling of lettuce also reduces the occurrence of the fungal root disease Pythium aphanidermatum. Chilling the nutrient tricks the physiology of the plant into growing in air temperatures that would otherwise not be economic. However, trials have shown that while root zone chilling via nutrient cooling can have these effects, the root zone cooling must be applied soon after early crop establishment and maintained for the life of the crop for maximum effect. While this technique of root zone chilling is perhaps more economically viable with high value crops in tropical climates such as cool season lettuce, herbs and other vegetables, it has also proven to be beneficial for other species. Warm season plants such as capsicum and cucumber have also been shown in research trials to respond in a similar way to root zone chilling when ambient air temperatures are higher than optimal for their growth and development. Cucumber is a warm season plant whose optimal root zone temperature lies around 25°C, once root temperatures increase to 35°C, severe reductions in shoot growth can begin to occur. Cucumbers grown at high air temperatures (38°C) have been found to have a larger leaf area and higher yield when the root zone was cooled to below 25°C. Capsicum (sweet pepper), another warm season crop has been found to respond to nutrient chilling when grown under warm aerial conditions in tropical Singapore. It was found that capsicum plants grown at a root temperature of 20°C had more leaves, greater leaf area and dry weight than plants grown at ambient root zone temperatures of 25 to 40°C even though both were under the same ambient tropical conditions of high temperature and light intensities. Under normal growing conditions for capsicum (22 to 26°C), having a nutrient solution temperature of 20°C would result in growth reductions, however, under the high temperature tropical conditions, root zone chilling to 20°C had significant benefits to crop growth and development via altering the physiology of

Maximum Yield UK | July / August 2011

Tropical lettuce production using DFT and chilled nutrients.

“...we know a cooler nutrient solution holds more dissolved oxygen for root uptake, so that oxygen starvation is likely to be less of a problem than it would be with a warm nutrient.” the plant to handle the temperature stress. Red basil plants, while normally considered a fairly warm season crop, have been found to have increased vegetative growth, more intensive development of purple anthocycanin pigment as well as increased development of aromatic compounds in the leaves when grown in a chilled nutrient at 25 to 26°C under tropical conditions. Cool season vs. warm season crops and nutrient chilling Obviously for the technique of root zone chilling via the nutrient solution to work effectively the correct temperature needs to be constantly maintained and this optimal temperature is likely to be not the same for all species. Cool season crops such as lettuce may benefit from nutrient chilling to a cooler temperature than warm season crops and there is evidence to suggest that root zone chilling is only beneficial when ambient air temperatures are consistently higher than optimal. Furthermore, as with any technique or treatment, overdoing

Even some warm season crops such as capscium have been shown to produce well under high heat and humidty with a certain degree of root zone chilling.

Chilled roots tend to be whiter, thicker and larger in mass than those grown at higher than optimal temperatures.

“Root zone chilling of the hydroponic nutrient solution is a technique...with cool season crops such as butter head lettuce, herbs and other vegetables.” than deep flow methods. It is possible that the larger volume of chilled nutrient solution in deep flow systems maintains cooler temperatures for longer, while the thin (two to three millimetres deep) flow of NFT and fine mist of aeroponics tend to heat up more during application. Another possibility is that the more of the root system that is submerged in the chilled nutrient, the greater the effect on the physiology of the plant. In general, however, solution culture methods are the only effective way of providing consistent chilled nutrient solution and in insulated systems can be reasonably cost effective. MY

References it can have some fairly drastic results— chilling the nutrient in a crop that is not under high air temperatures could potentially result in growth reductions or chilling damage, particularly with warm season plants. Such over chilling results in root tissue damage and decay, reduction in nutrient ion absorption and water uptake.

Best systems for nutrient chilling Various studies on the effect of nutrient or root zone chilling for hydroponic crops under high heat conditions have shown that deep flow water culture gives the best results for many crops such as lettuce, herbs and other vegetables. Aeroponics and nutrient film techniques are also commonly used for root zone chilling; however, these seem less effective

He J, Lee SK and Dodd IC., 2001. Limitations to photosynthesis of lettuce growth under tropical conditions: alleviation by root zone cooling. Journal of Experimental Botany Vol 52(359): 1323-1330. Thompson HC, Langhans RW, Both AJ and Albright L D., 1998. Shoot and root temperature effects lettuce growth in a floating hydroponic system. Journal of the American Society of Horticultural Science Vol.123(3) 361-364. Dodd IC, He J, Turnbull CGN, Lee SK and Critchley C., 2000. The influence of supraoptimal root zone temperatures on growth and stomatal conductance in Capsicum annuum L. Journal Of Experimental Botany Vol 51(343) 239-248.

Maximum Yield UK | July / August 2011

For

Peat’s Sake The Peat Problem and Alternatives by Michael Bloch

Active green guru Michael Bloch examines the controversial peat problem and suggests alternatives for gardeners Peat, which forms in wetlands, is a deposit of partially decayed vegetation matter. Peat moss (sphagnum) commonly grows in peat bogs. Peat and peat moss is sought after by gardeners for adding nutrients to poor soil and assisting with water retention. Peat moss is used in hanging baskets as liners and as biodegradable pots for seedlings. Peat can also be used as a solid fuel once dried.

The problem with peat The wetlands (also known as peatlands) where peat forms are unique ecosystems, so when it is dug up, those ecosystems are disrupted. As peat can take anywhere from a couple hundred to thousands of years to form, the wetlands are almost irreversibly damaged. In some parts of the world, most peatlands have been

“The wetlands where peat is formed are unique ecosystems, so when it is dug up, those ecosystems are disrupted.”

Maximum Yield UK UK | July | July / August 2011

destroyed and the government is taking action to preserve what remains. Peat deposits in Southeast Asia could be destroyed within the next few decades Peatlands are also massive carbon sinks estimated to store anywhere up to 455 petagrams of carbon, which is 5 × 1011 short tons—in other words, a lot. When peat burns, it’s like burning coal; much of the carbon content in the peat is released as carbon dioxide—the greenhouse gas of primary concern in relation to global warming. The burning of peat unlocks carbon that has been sequestered for centuries and by burning it faster than peat can be produced, we’re just adding to our climate change woes. The harvesting of the peat moss is simply unsustainable. It’s a slow growing plant and so much of it is needed to form the bricks that are favoured by gardeners.

Peat alternatives For the gardener, there are some environmental and economical alternatives to peat and peat moss. The most popular choice is coconut coir, which is a waste product from coconut processing. It can be used as hanging basket liners, potting medium, mulch cover or as a soil conditioner. Some research has also concluded that coconut coir actually retains more water than peat moss.

“Another alternative mulch material is cocoashell, which is a waste product from the production of chocolate.” Bricks of coconut coir will expand up to 10 times their original size once soaked in water. Seed pots made from coconut coir are also available. A replacement for peat itself is simple— compost.You can buy it (e.g., composted manure) or make compost yourself and save some cash. Compost made from your kitchen refuse, bark chips or leaves is a good peat replacement. Another alternative mulch material is cocoa shell, which is a waste product from the production of chocolate. It has an added benefit of repelling cats. Yet another alternative is dried alfalfa. Like peat moss and coconut coir, it retains a great deal of water and adds nutrients to the soil. For an ultra-rich soil conditioner, consider starting up a worm farm (aka vermicomposting) as the castings are prize fertilizers. Worms will eat all sorts of household waste including cardboard and egg shells. If you have children, they’ll most likely love getting involved too. MY

Maximum Yield UK | July / August 2011

by Philip McIntosh

Plant Nutrient Elements: Part 1 The Macronutrients P, N, K, Mg, Ca and S

Elemental Plant Chemistry Nitrogen Plants need mineral nutrients to support the myriad biochemical proRole in Plants. Nitrogen (N) is present in plants in the cesses that occur in their cells. In nature plants get these nutrients from largest concentration of any of the mineral nutrients. It is a the soil through their roots (or through leaf feeding). Hydroponicallycomponent of many organic molecules of great importance, grown plants absorb essential minerals through their roots from an including chlorophyll and the energy transfer molecules aqueous solution. adenosine triphosphate (ATP) and adenosine diphosphate Although there are 92 naturally occurring elements, there is some dis- (ADP). Nitrogen is a component of amino acids, which are agreement as to the exact definition of essential. Hydroponics has been the molecular subunits from which proteins are synthesized. crucial in allowing scientists to determine which elements are required The nucleic acids DNA and RNA also contain nitrogenous and which are not. bases that make up the genetic coding sequences. For an element to be considered Hydroponic Source. Nitrogen essential in plants, the following four in hydroponic nutrient solu“Hydroponics has been crucial in allowing criteria should be met: (1) It must be tions is supplied in the form of scientists to determine which elements are required for the completion of the nitrogen salts containing nitrate required and which are not.” lifecycle of the plant; (2) it cannot be (NO3-) or ammonium (NH4+). replaced by some other element; (3) A combination of both of these it must play a direct and specific role in plant metabolism; and (4) it offers some desirable pH buffering in the solution. Nitrates of must required by a substantial number of plant species, not just a single potassium, calcium and ammonium, or ammonium phosphate are commonly used to formulate hydroponic nutrient solutions. species or two.This fourth “rule” can lead to disagreement among scientists. For the purposes of this article, we’ll discuss the 16 main eleIn cases where the addition of no other nutrient elements is ments that are accepted by most as essential.This article, the first of two, desired, nitric acid is an option. Deficiency Symptoms. Nitrogen deficiency in plants discusses the six so-called macronutrients. Macronutrients are found is characterized by chlorosis, which is a yellowing of the in plant tissues in notably higher concentrations than the other class of leaves. Nitrogen is a mobile element in plants, and can be nutrients—the micronutrients. Carbon, hydrogen and oxygen, which moved around as needed; thus, older leaves tend to be the are not usually considered “mineral” elements will not be discussed. 28

Maximum Yield UK | July / August 2011

Typical chlorosis on older leaves of tobacco plants caused by nitrogen deficiency. (R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org)

first plant parts to show signs of nitrogen deficiency (as nitrogen is transported to support new growth). Chlorosis is often evident when other minerals are deficient as well. Plants grown in poor nitrogen conditions tend to have stunted growth, and abnormally thin shoots. Excess Symptoms. Excessive nitrogen in plants is evident as abnormally dark green leaves. Plants that have absorbed too much nitrogen are not as hardy, and more susceptible to attack from insects, bacteria and fungi. Phosphorus Role in Plants. Phosphorus is a part of the previously mentioned energy molecules ATP and ADP and is found in the backbone portion of both DNA and RNA. Many organic molecules contain a phosphate group and amino acids incorporated into proteins may be phosphorylated after protein synthesis. The phosphorylation and dephosphorylation of proteins is an important mechanism in regulating the activity of proteins. Cell membranes are rich in phosphate groups that are part of the “head” regions of the phospholipid molecules that form the membrane bilayers. Hydroponic Source. Phosphorus is usually provided in hydroponics solutions as mono- or dihydrogen phosphate. In either case, the actual species in solution is pH dependent, with monohydrogen phosphate favoured near neutral (pH about 7.0) and dihydrogen phosphate favoured at more acid pH. Phosphorus is provided in conjunction with either potassium or nitrogen in the form of ammonium or potassium phosphates. In instances where there is already enough of either potassium or nitrogen in the solution, phosphoric acid is an option. Deficiency Symptoms. Phosphorus (P) deficiency can be difficult to diagnose. Since phosphorus is important in many metabolic functions as well as in the synthesis of new cell membranes, phosphorus deficiency results in slow growth. In a moderate case, the leaves become a darker green than normal with perhaps a blue or purple tint, which can give the illusion of a healthy plant. “A lack of calcium interferes with normal cell division and elongation, causing blossom end rot on developing fruit.”

Maximum Yield UK | July / August 2011

“Plants grown in potassium deficient conditions show a distinctive yellowing at the tips and edges of the oldest leaves.” In addition to darker leaf colour, plants will exhibit stunted growth and thin stems, with longer than normal distance between the branches. In severe cases of phosphorus deficiency chlorosis appears followed by leaf curl and drop. Excess Symptoms. The possibility of phosphorus toxicity is somewhat greater in hydroponically grown plants. The problem likely arises from its interaction and interference with other elements such as iron, magnesium and especially zinc. For this reason, the symptoms of toxicity, if they are detectable at all, will likely present as symptoms associated with one of these other elements. Potassium Role in Plants. Potassium (K) does its job as a small monatomic ion (K+) in plants. It has diverse roles, including acting as a cofactor for the function of many enzymes important in energy production and carbohydrate metabolism and catabolism. Potassium ions are a critical part of the system that controls the movement of water in and out of leaves. It also facilitates water uptake by roots, which is probably a more important function in soil-grown plants. Hydroponic Source. Potassium is supplied as potassium nitrate or sulphate. If no other source of chloride is available for the solution, potassium chloride (KCl) is an option. Deficiency Symptoms. Like nitrogen, potassium is highly mobile in plants resulting in deficiency symptoms appearing in the oldest foliage first. Plants grown in potassium deficient conditions show a distinctive yellowing at the tips and edges of the oldest leaves. As the yellowing spreads, the leaves die and turn brown at their peripheries giving a burned appearance. Since K+ ions are important in maintaining water balance and turgor, potassium deficient plants are sensitive to water stress and wilt easily. Excess Symptoms. Too much potassium is not directly toxic to a plant. However, the balance between the concentrations of potassium, calcium and magnesium ions is important, and too much K+ can be detrimental. An excessively high potassium to calcium ratio causes magnesium or calcium deficiency. Calcium Role in Plants. Most of the calcium (Ca) in plants is found embedded in the cell walls where it has a structural role, and in membranes where it influences the flexibility of membranes. Changes in the normally low concentration of calcium ions found in the cell cytoplasm are thought to be involved in signalling environmental stress. Hydroponic Source. Calcium nitrate is the reagent usually chosen to supply calcium in a nutrient solution. Many water supplies contain significant calcium and this should be taken into account before deciding how much calcium salt to include in a formulation. 30

Maximum Yield UK | July / August 2011

Purple colouration of corn leaves caused by phosphorus deficiency. (Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org)

Deficiency Symptoms. Newly emergent leaves are usually the first parts of a plant to show symptoms of calcium deficiency. The young leaves will be malformed, with ragged margins, and eventually turn brown. Roots also are affected and will turn brown (or translucent in some cases), and develop a swollen bulbous appearance accompanied by stunted growth. In fruit bearing plants, a lack of calcium interferes with normal cell division and elongation, causing blossom end rot on developing fruit. Excess Symptoms. A proper balance between the concentrations of potassium, calcium and magnesium ions is important. Too much calcium can result in either magnesium or potassium deficiency. Magnesium Role in Plants. A magnesium ion is found at the central position of every chlorophyll molecule, making it an important part of the photosynthetic apparatus. Magnesium ions also serve as enzyme cofactors, notably in ATP metabolism. Some magnesium is also present in cell walls. Hydroponic Source. Magnesium sulphate is the most common magnesium source for hydroponics. The amount of naturally occurring magnesium in the feed water should be determined before deciding how much reagent to use. Deficiency Symptoms. Because of the importance of magnesium in photosynthesis, a lack has a profoundly negative effect and is difficult to recover from when it happens.

Left: Leaf tip burn typical of calcium deficiency in cabbage. (David B. Langston, University of Georgia, Bugwood.org) Right: End rot of tomato fruit brought on by calcium deficiency. (David B. Langston, University of Georgia, Bugwood.org)

Typical chlorosis in tobacco plant caused by sulphur deficiency. (R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org)

Chlorosis between the veins of older leaves is a good indicator, with perhaps the addition of a red or orange tint. Growth is strongly inhibited. Magnesium has a complex relationship with Ca2+, K+ and NH4+ ions, and an imbalance among them can lead to magnesium deficiency. Excess Symptoms.The main risk of having too much magnesium in solution is in creating an imbalance with respect to other ions, especially calcium. For this reason, the Ca and Mg concentrations should be about the same to avoid problems.

Philip McIntosh

Sulphur Role in Plants. Although only two amino acids contain sulphur (S), few proteins would function normally without them. Sulphur is found in plant hormones, and in molecules involved in chemical defence, odour and taste. Many organic molecules, intermediate compounds and proteins, contain or are modified with sulphate side-groups. Hydroponic Source. Growers have a choice of several other nutrient ions to pair up with sulphur when designing nutrient solutions. Potassium, magnesium or ammonium sulphates are all good options. Deficiency Symptoms. Sulphur deficiency is difficult to distinguish from nitrogen deficiency. One difference between the two is that a lack of sulphur tends to cause more of an overall yellowing of a plant, rather than a yellowing of the older leaves first. Excess Symptoms. There is little evidence that plants are harmed by high concentrations of sulphate ion. Stay tuned for the September/October issue of Maximum Yield UK where we will discuss the micronutrients. MY

References Barack, Phillip (1999), Essential Elements for Plant Growth, http://www.soils.wisc.edu/~barak/ soilscience326/essentl.htm (accessed 09/06/09) Jones, J. Benton (2005), Hydroponics: A practical guide for the soilless grower, CRC Press, Boca Raton, FL

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Plants and

Sounds

by Evan Folds For growers, the idea of talking or singing to your plants may be the inputs—that output—that you’ve been ignoring.

Maximum Yield UK | July / August 2011

Most of us know somebody or have heard a story of someone who speaks to their plants. Even Prince Charles is well known for his fondness of conversing with plants, saying in a television interview in 1986 that it was “very important” to talk to plants and that they “respond” when spoken to. It is always interesting to hear the stories of success offered by people who profess to whispering sweet nothings or singing their favourite songs to their plants and others tell of how they notice that certain types of music have markedly different effects on their plants. This subjective certainty is born of practice and intuition and is quite lost from the modern approach to science, but is shouldn’t be ignored. It’s easy to be confused when discussing the idea of frequencies. We measure light and sound in the same way (hertz), but how are they different? We have to rely on instruments to measure these frequencies and most of what we pay attention to is the numbers, not what the numbers actually mean. When we think of measurable frequencies in regards to growing plants, most of our attention is directed towards the visible portions of the electromagnetic spectrum (ROY G BIV). The electromagnetic spectrum is defined by light waves and, in addition to the visible portion, is comprised of radio waves, infrared, x-rays and gamma rays. However, the electromagnetic spectrum does not contain sound waves.

"Light, electricity and magnetism are all manifestations of electromagnetic radiation and do not need a medium to travel through, but sound waves are like ripples in a lake or a flag." Light, electricity and magnetism are all manifestations of electromagnetic radiation and do not need a medium to travel through, but sound waves are like ripples in a lake or a flag. They rely on the molecules in water and air to get from A to B, which is why light waves travel through space and sound does not. Considering this, when was the last time you paid attention to what it sounds like in your grow room? What if the question was not which light to purchase, but what album? The sounds of nature are innumerable and clumsily consistent, resulting in a symphony of subtle sounds flowing together to create a living and vibrant concerto. Since time immemorial plants have been serenaded in these seasonal sounds and have come to rely on them in the same way they have other environmental factors for growth. Of course, one should not expect to be able to replicate this natural phenomenon with any exactness, but with persistence and research we can tap into this symbiosis in order to enhance the growth of our plants, or more directly, attempt to replicate the natural environment from which they have been removed. Researchers have demonstrated that plants respond to acoustic energy in profound ways that not only influence their overall health, but also increase the rate of growth and size of the plant. Through years of research and a stroke of spiritual insight, Dan Carlson determined the combination of frequencies found between 3,000 to 5,000 kHz causes the stomata of plants to open and absorb nutrients more efficiently. Because

Maximum Yield UK | July / August 2011

the ability and desire of the plant to take up nutrition was altered due to its enhanced capability, it took 15 years to develop a corresponding foliar spray designed specifically for use with the sound frequencies Carlson called Sonic Bloom. His insight has been used by countless farmers and even resulted in growing the largest indoor plant on record according to the Guinness Book. Purple Passion plants normally grow about 45 centimetres and live 18 months. When treated with the Sonic Bloom process, Carlson’s plant grew to 396 metres and was still alive 25 years later. Sonic Bloom has been chronicled in the book “Secrets of the Soil.” Another pioneer in the realm of acoustic gardening is Joel Sternheimer. He studied elementary particle physics at Princeton and through his studies of scale resonance was inspired to investigate the vibrational frequencies of amino acids. The ribosome is the factory of the cell; it catalyzes the creation of proteins from a variety of 20 amino acids depending on the needs of the cell and the corresponding organism. During this process of translation in the ribosome, the amino acids are considerably slowed, allowing researchers to measure the specific frequency of each one as a “note”. When the sequence of a certain protein is recognized, each amino acid (note) can be transcribed into a sequence or melody. When Sternheiner successfully replicated the correct melodies for the selected proteins he noticed that it encouraged the production of the corresponding protein and stimulated

Maximum Yield UK | July / August 2011

growth. After all, amino acids are critical to life. Sternheiner has filed for several patents based on his work and claims that tomatoes exposed to his melodies grew 2.5 times as large as those that were untreated. In the landmark book “The Secret Life of Plants” (1973) the research of Dorothy Retallack is investigated. In order to complete her music degree she chose to experiment with plants using different types of music as a laboratory experiment. Amazingly, through rigorous trial and error she determined that plants prefer classical music—such as Brahms, Beethoven and Schubert—over rock and roll—such as Zeppelin and Hendrix. Oddly, Jazz recordings from artists such as Duke Ellington and Louis Armstrong resulted in roughly half of the plants being experimented on leaning towards the speaker and half leaning away. Through more experimentation Retallack concluded that it was not the genre of music having the influence, but the range of instruments and resonance used. She determined that the percussion frequencies of music were harmful to plants, resulting in as little as 1/4 the root growth of control plants and in some cases death. It is research such as this that forces us to consider the subtle senses of plants. Specimens such as Mimosa pudica and the Venus Fly Trap

are sensitive to touch, so is it not plausible that plants can also listen? In 2007 South Korean scientist Mi-Jeong Jeong claimed playing Beethoven’s Moonlight Sonata to rice plants encouraged quicker growth and blossoms to bloom earlier. The researchers claim they have identified plant genes that can “hear”, potentially allowing farmers to switch specific plant genes on and off with enormous repercussions. The results showed that sounds at specific frequencies—125 hertz and 250 hertz—made genes rbcS and Ald more active, whereas sound waves at 50 hertz made them less active. Because both are known to respond to light, they repeated the experiments in the dark and concluded definitively that the sound was causing the effect. The researchers speculated that the production of chemicals that lead to the genetic changes they observed could be harnessed to activate other specific genes that could trigger the enhanced flowering of crops. In a more recent development, the Royal Horticultural Society (RHS), Britain’s leading gardening charity dedicated to advancing horticulture, has initiated a serious study investigating the efficacy of talking to plants. Gardener Colin Crosby says, “We know that sounds of between 125 hertz and 250 hertz can affect gene expression in plants and help them grow, but this has only been tested using music. For the first time we will be able to advise people not only whether it’s worth talking to their plants but exactly how it should be done. We may even be able to standardize the practice by recording the perfect voice for those less confident in conversing with their plants.” Toby Buckland, lead presenter on BBC Gardeners’ World, says, “A lot of thinking behind this is that if a gardener is relaxed, it helps the plants grow better. Plants do pick up on your stress, that’s something that’s well known, and if you’re not confident, it’s as if it’s a self-fulfilling prophecy for failure.” (http://news.bbc.co.uk/2/hi/uk_news/7973727.stm) It turns out that sometimes plants create sounds themselves as well. On a business trip into the backwoods of Siberia in 1994 an entrepreneur named Vladimir Megre met two elderly gentlemen who told him about the amazing properties of the Siberian cedar. The men explained to Vladimir that the trees grow to be around 500 years old, but every 1,000 years or so after 550 years of its life, one of the elderly trees begins to ring audibly. As the two men described, the Siberian cedar is a conduit of high amounts of beneficial energy and this is the trees way of communicating that it is ready to share. After Vladimir’s return to the place where he met these elderly men he met their granddaughter Anastasia, who he lived with for a period of time in the taiga of Siberia. Anastasia taught Vladimir many things and showed him how she was attempting to help right the wrongs of the world from afar. From his experiences, and despite the fact that Vladimir is not a writer, he has written eight books about his experiences that have now been translated into over 20 different languages and been remarked upon by people ranging from the President of Russia Dmitriy Medvedev to the author of “Chicken Soup for the Soul” Mark Victor Hansen. The book series, as well as pendants, nut oils and other Siberian cedar related products, can be found under the name Ringing Cedars of Russia on a simple web search. We certainly didn’t learn about any of this in school, but open your mind and you may be surprised what you might find. Next time someone tells you you’re crazy for talking to your plants, you can tell them where to go… to the local library. MY

Maximum Yield UK | July / August 2011

CLIMATE by RĂŠal Adam and Isabelle Lemay

CONTROL Stay in (climate) control in the grow room and avoid unpredictable and deadly results.

Keep the stomas open Plants are living organisms with failsafe mechanisms encoded in their DNA to survive the ever-changing climate conditions in a natural outdoor environment. They act a bit like each species has its own personality, and they are sort of moody when it comes to climate conditions. Plants breathe through stomas, mainly located on the lower surface of leaves. These stomas act like two-way valves to let air in, and expel unwanted gases and water vapour from transpiration. When a climate condition is threatening to damage a part of or the whole plant, the stomas close. Even if light, water and nutrients are available in abundant quantity and quality, when the stomas shut the photosynthesis stops, as does all growth and blooming. The plant maturation stops until the climate variable that caused the stomas to close gets back into the appropriate range for the plant to comfortably carry out photosynthesis and growth. So, climate conditions are important to plants, and climate control in a closed environment is a must. If temperatures are too hot or too cold, or if the relative humidity is too low, growth stops. When relative humidity is too high transpiration is slowed, so water and nutrient absorption slows accordingly. Relative humidity going too high is also a concern because of the risk of pests like fungi and bacteria, which will attack plants if allowed to develop.

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How important is CO2?

Basically, when stomas close the carbon intake from breathing carbon dioxide shuts down and the plant is deprived of this important source of building material for the cells. Plants are made up of organic chains composed of oxygen, hydrogen, nitrogen and carbon. If any of these atoms are unavailable in the right proportions, tissue building and growth are slowed to use just what’s available. Since hydrogen, oxygen and nitrogen may come from water pumped through the roots, carbon dioxide from the air becomes central to further fast growth. Proper temperature and relative humidity will keep the stomas open for carbon dioxide intake in the presence of light. That’s why it is important to maintain at least minimum ventilation with fresh air to supply the plants with carbon dioxide as it is drawn and used. Climate control is obviously important to maintaining proper conditions for growing plants at a sustained high rate in a closed room. When plants first appeared on Earth and evolved into the various species, carbon dioxide levels were much higher than they are now. These concentrations of CO2 were certainly above 1,000 parts

“So many species of plants will react, grow and mature faster at higher levels of carbon dioxide.” per million (ppm), compared to the 400 ppm average that can be measured outdoors today in a highly urbanized area. So many species of plants will react, grow and mature faster at higher levels of carbon dioxide. That’s why carbon dioxide enrichment is extensively used by growers, providing more building material for the plant to transform into biomass and to get faster and higher yield results. MY

Maximum Yield UK | July / August 2011

Beet Goes The

Whether you’re after a nutritionally-infused side dish or salad addition, or you’re craving something sweet for supper, beets are the perfect indoor crop for you.

Maximum Yield UK | July / August 2011

With its distinctively sweet flavour, and deep purplish-red shade, it is surprising that we don’t hear more about the very versatile root vegetable known as the beet. Grown outdoors, the beet will peak in the winter and summer, but brought inside, this antioxidant-rich vegetable will grow all year. Beets are rich in folic acid and betacyanine, the antioxidant that gives beets their rich colour. The entire plant is useable with a wealth of nutrients in the savoury greens as well as the texturized beet plant. Betacyanines have been known to fight and prevent various types of cancer, particularly colon cancer. Because of its superior cleansing abilities, it is a good choice for maintaining a healthy liver. Beets are also recommended for kidney, gallbladder, stomach and intestinal problems. Beets provide rich amounts of calcium, iron, magnesium and phosphorus—a good tonic for the blood, and are also said to strengthen the heart. They will grow well under a variety of light sources including fluorescents, incandescents, high pressure sodiums, metal halides and LEDs. The seedlings are best started under fluorescents or LEDs. Beets thrive in a wide range of temperatures and take up very little space, making them an ideal choice for an indoor crop. They should be fed lightly with food that is high in nitrogen and watered well. Watch out for black, rough scabs on the plants as that may be a sign of boron deficiency. Beets also prefer a neutral pH (7.0).

The ways in which one can enjoy beets are limitless. Here are just some of the many ways that beets can be prepared: • steamed or sautéed • beet juice • salad addition or beet salad • healthy side • appetizer • beet slaw • spring rolls • gingered • soup/borsch • roasted • boiled Although beets can be picked at any size, the best flavour can be found when they are pulled at full size. And don’t forget, you can eat the greens too. MY

Maximum Yield UK | July / August 2011

by Clair Schwan

The Basics for Indoor Vegetable Gardeners Even indoors nature can accomplish pollination, but sometimes a little human help is needed. Pollination of vegetable plants can be a problem for indoor gardeners because, well, your plants are indoors and not outside where natural pollination can take place. It’s a common concern for beginners with a greenhouse. Let’s take a general look at what pollination is and how we might handle such a task with our indoor gardens.

What is pollination?

Pollination is part of the reproductive cycle of plants. It involves transferring pollen from male parts of flowers to female parts of flowers to fertilize the plant. Fertilization is essential so the plant can produce seed.

Maximum Yield UK | July / August 2011

Some plants are self-fertile so they don’t need pollen from another plant. Their blossoms can fertilize themselves (within the same flower or from a flower on the same plant). Other plants require cross-pollination where pollen from another similar plant is used to fertilize the flower. Vegetables like carrots, beets and broccoli are productive in the absence of pollination, because their seed is produced after it provides its food source to us.Vegetables that bear fruit like tomatoes, peppers, eggplant and squash, require pollination for the fruit to set, so it’s essential that pollination take place.

How are plants pollinated?

There are four basic ways that pollination takes place: animal contact, wind, self-pollination and human assisted pollination. Here are some examples of each type of pollinator at work. The overwhelming majority of plant pollination is performed by animals as they go about searching for food. Animal

pollinators include birds, flies, moths, butterflies, and most importantly, bees. The best pollinators out there are the humble and hard working bumblebee and honeybee. While these animals search for sweet nectar, they help pollinate your vegetable garden. In our greenhouses, bumblebees can become completely covered in pollen while visiting squash blossoms. Wind is another good pollinator. Corn is probably the best example to illustrate how wind pollination works. Pollen is blown by the wind from the tassels on top of the corn plant to the corn silk that hangs out of the end of each ear of corn. That’s why corn is best planted in multiple adjacent rows instead of single rows. Many types of plants are self-pollinating. Some plants pollinate themselves by having the male portion of the blossom grow into contact with the female portion. This can happen even when the blossom is closed. When growing plants indoors, the chance of pollination by animals and wind is reduced, so that’s where we humans have to get involved to make certain our plants are pollinated. Sometimes it requires a small paint brush, and sometimes we just need to shake the plant a bit or create air circulation to promote pollination.

act as the pollinator in the absence of bees. Gently swirl it inside of a male flower to pick up pollen, and then brush it lightly inside the centre of the female blossoms.

An alternative to pollination

Wouldn’t it be great if you didn’t have to be concerned about pollinating your indoor vegetables? Well, you don’t have to if you grow cucumbers especially bred for use in a greenhouse. They’re known as European greenhouse varieties. They produce nearly all female blossoms, require no pollination, and produce an abundance of seedless cucumbers.

So, there you have it, the basics of pollination for fruit set and seed development. To be on the safe side, I always help along my vegetable plants until I see that an abundance of bees have found their way into the greenhouse to pollinate the plants. MY

Pollinating indoor vegetables

There are several methods for making certain your indoor vegetables are well pollinated. The easiest approach to indoor pollination is to provide an opening for insects to enter. Bees will naturally find their way into your greenhouse or other indoor growing area if you give them an opportunity. An open vent or an open door is all they’ll need if they’re plentiful outdoors. Tomatoes are mostly self-fertile, yet some have blossoms that don’t open, so they can’t be pollinated by bees or other insects, and indoors the wind can’t get to them. To ensure adequate pollination, just shake the plant lightly every few days after blossoms appear. This will help dislodge pollen inside the blossoms for fertilization that will help set fruit. Squash plants have both male and female flowers. The male flowers are the first to appear and each lasts only a couple of days. A week or so later you’ll see the female blossoms appear. They have tiny fruit on the bottom of the blossom. As soon as the blossom opens, use a small water colour paint brush and

Maximum Yield UK | July / August 2011

TALKING SHOP

AT A GLANCE Store Name: Cheshire Hydroponics Owner: Jay Larkin and Lee Crabtree Location: 17 Hillgate Business Centre, Hindley Street Stockport, Greater Manchester, United Kingdom Phone: +44 (0) 161 429-6802 or +44 (0) 845 272-5266 Web: www.cheshirehydroponics.co.uk

The Cheshire Hydroponics team is ready to serve Greater Manchester growers.

They’re doing some renovations at Cheshire Hydroponics in Stockport, and owners Jay Larkin and Lee Crabtree are eagerly anticipating the new look. “The building is being redecorated,” Jay tells us, “and the store layout is really presentable now. Over the next few months we will be striving to get it looking in tip-top condition to rival our competitors’ stores.” Although Cheshire Hydroponics has only been open since March of 2010, the two partners are very pleased about the direction their retail shop is heading and the future looks bright.

“In the beginning when the company was first born we started with minimum staff and gradually built ourselves up to the team we are today,” says Lee. “Now we have a friendly welcoming team of eight who you can ask anything, and they are always there and on hand to help you with whatever it is you may want. No question is too big or small—we can answer them all.” Lee started the shop originally and Jay was pretty excited when he was offered the chance to come on board as a partner. “I was a builder, and I was also buying and selling cars when Lee and I first talked about [opening a store],” he says.

Co-owner Jay Larkin (pictured) partnered with Lee Crabtree and the two turned their hobby into a business.

Maximum Yield UK | July / August 2011

is 100 per cent satisfied and always comes back time and time again.” Customer service is what Jay and Lee have built their reputation on, but it’s only one piece of the puzzle. In the hydroponics business, you’ve got to carry the stuff people want to buy—or you’ve got to be willing to go get it. “We first sold just the basics, the more popular nutrients such as Canna and Ionic, but as the customer base grew so did the range of products required to suit them.” Jay says. “But now we carry a vast range of products catering for all gardeners—whether you’re a novice or an expert,” continues Lee. “If there is anything at all our shop is missing we will get it in for you, and The hydroponic industry is booming, and with a customer-focused philosophy, Cheshire we can guarantee we will strive to always Hydroponics is leading the competition. get what you want when you want it. Jay “but I had always been keen on gardenfound that staying in the same place has will drive anywhere—he’s so far driven ing and landscaping. I would consider allowed us to keep the customers we to Leeds and Liverpool—and he will myself green-fingered, so when Lee asked already have and attract new customers go further, as he wants to make sure his me if I’d like to join him, I decided to through word-of-mouth.” customers are always satisfied.” turn my hobby into a business.” Jay and Lee are happy in their “Stay loyal and deliver what we promise work and it rubs off onto their Like all start-up stores, Cheshire Hydroponics went through its every time. We really found the key is to clientele. Business is good, and with early struggles. their recent promotional initiatives come through for your customers.” “Like any other business starting and a new look for the shop things out we struggled with competiare only going to get better. tion, cash flow and generally developing a Of course, customers aren’t going to And what’s the most important thing reputation,” says Jay. keep coming back unless you can offer for these two entrepreneurs as they They didn’t have a lot of start-up cash, them something special—after all, the move forward? but Jay and Lee knew that job one was field of hydroponics is booming, and it “It’s always customer service,” Jay says withgetting their name out there in the hyseems like stores are opening up all over. out hesitation.“The level of service we dedroponics community. “Our company’s philosophy is simple,” liver to our customers is first class, and that’s “With little funding at the start, we used says Jay. “Stay loyal and deliver what we the real strength of this company.” MY the Internet, social networking sites and promise every time. We really found the of course our own interactive website to key is to come get our name out there,” Jay explains. “We through for your also have a radio interview coming up that customers. We will should boost our advertising, and we have always go the extra recently redone all our signage and put up mile for them, even new posters in new places.We also have a if it means drivnew catalogue and leaflets, and a re-vamped ing to a distribuwebsite that should be easier to use.” tion outlet to get And soon enough their efforts were bewhat the customer ing rewarded, as customers started coming needs—we will in and then kept coming back. go that extra mile “First of all, we’re lucky to be in a prime every time to make The environment at Cheshire is chill and fun, and pool breaks are encouraged. location,” Lee says. “And we’ve definitely sure our customer Maximum Yield UK | July / August 2011

PRODUCT spotlight

Continued from page 19

Hotbox Superb Dual Output Fan Heater The Hotbox Superb is a 2.8 kilowatt electronically controlled fan heater. With winter and summer settings, it can help keep your glasshouse or greenhouse cool or warm depending on the season. It is versatile and features half and full heat settings and a fan only setting depending on your needs. The Hotbox Superb is a high output fan (250 cfm, 450 cubed metres per hour) made of stainless steel construction with sealed elements. It is fitted with feet and hanging loops and includes a remote temperature sensor. Ask your local hydroponics retailer to carry the Hotbox Superb today.

Boldtbags Large Cone 3 Bag Kit The Boldtbags Large Cone three bag kit makes filtration easy and efficient. Available in all the micron grades of the regular Boldtbags but the micron screen continues to the top where it attaches to a metal ring. The bag is tapered creating optimum downward flow, as well as out through the sides of the bag once product starts to collect at the base. The Large Cone tapers to a straight edge, and once all excess liquid is wrung from the bag, it can be inverted to produce a “brick” of extract or nutrients. Visit your favourite indoor gardening shop for more information.

HOMEbox XXL+ The HOMEbox XXL+ was designed for growers who think. It offers easy access through the front and back and is made of highly reflective material. It features the same great concepts as the conventional HOMEbox but with a brand new cover concept that enables one person to set it up with ease. Featuring high tech German design and engineering, the new HOMEbox XXL+ is an essential building block for successful and safe growing. Rugged materials ensure a long life and all parts are replaceable. The additional flooring is heat-sealed and water resistant. It features inlet and outlet tubes, ventilation windows, a tough outer shell made of canvas, thick, reflective polyethylene lining and a metal structure with strong and precise nylon push-lock corners. For more information visit your favourite grow shop.

Plant Magic Plus Root Stimulant - Excellent Value for Money Plant Magic Plus Root Stimulant stimulates the biological activity around the plant’s root zones leading to explosive, healthy and strong root development. Plants that use Root Stimulant also show greater resistance to stress from lack of water, heat/cold or transplantation. High quality humate is involved in the uptake of nutrients by plants, microbial activity and the cycling of nutrients. Amino acids are the fundamental building blocks of proteins that can be absorbed directly and readily via the roots or stoma (the pores in the leaves). Certain metals can bind to these blocks, allowing the plant to absorb these immediately. This allows the plant to receive important elements quickly and efficiently. A boost of micronutrients and natural plant hormones help the plant grow stronger, faster. Ask for Root Stimulant now at your local indoor gardening shop.

Maximum Yield UK | July / August 2011

Boldtbags 23 Litre 4 Bag Kit The Boldtbags 23 litre four bag kit offers the perfect range of filtration with the 220, 160, 73 and 25 micron bags. Boldtbags are made from heat-fused nylon and FDA approved watertight lining. The Swiss grade mesh screens have been measured to the absolute micron and heat-stamped to prevent fluctuation. Boldtbags use reinforced military grade nylon stitching and are bolted at the stress points to keep everything in the bags and not on you. The durable nickel-plated grommets can be used easily with suspension systems and will never rust. Visit your local indoor gardening shop for more information.

Phat Mufflers Phat Mufflers are made using an all aluminium 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.

Hotbox Sirocco Dual Output Fan Heater The Hotbox Sirocco is a 1.8 kilowatt electronic controlled fan heater. It can help control air circulation or heat your glasshouse or greenhouse. It is versatile for all needs and features a fan with heater setting and a fan only setting. The Hotbox Sirocco is a high output fan made of stainless steel construction with sealed elements. It is fitted with feet and hanging loops. It also features a remote temperature sensor. For more information visit your local indoor gardening shop.

Maximum Yield UK | July / August 2011

DO YOU

know?

COMING UP IN march april september - october 2011

Chelated Micronutrients Discover the several forms of trace mineral chelates and learn why amino acid chelates are particularly beneficial.

Cool Toys and Tools for Hydro Growers 1 2 3 4 5 6 7

A sulphur deficiency and nitrogen deficiency look very similar in plants, the one distinction being a sulphur deficiency shows up as overall yellowing of the plant, rather than yellowing of the older leaves first. Research has shown that even a short duration, less than 30 minutes of root zone heat buildup, can have a very negative effect on many crops. It took 15 years to develop a corresponding foliar spray designed specifically for use with sound frequencies, a process that has shown to increase growth rates in plants with extraordinary results. Plants absorb and store plutonium—but plutonium is not an essential element. CO2 is a ‘supernatural’ occurrence for a plant in nature at extreme levels, and your garden can literally become addicted to what it is being served in excess. The positive effects of nutrient chilling seem to be largely the result of changes in the production of plant growth hormones abcissic acid (ABA) and cytokinins that control a range of plant responses. Almost everything a plant requires to grow and develop is manufactured in the leaves—hormones, metabolites, proteins and amino acids.

The wide range of exciting and useful tools, meters and instruments designed for horticultural applications provide valuable, educational information, but they’re also fun. This short list will inspire you to spend even more time with your plants.

The Cost of Sunlight Unlike most agricultural inputs, the sun’s energy is generally left off the balance sheet, as farmers usually assume that sunlight has no monetary cost. However, agricultural use of sunlight is far from free. So, what is the true cost of sunlight?

Talking Shop With… The Greenhouse Effect is a family business, located in the village of Wavendon, and man are they passionate about hydroponics.

www.maximumyield.com Growing beets for health, climate control, plants and sounds, new products, industry news, event updates, new UK-exclusive competitions and more!

Maximum Yield UK (September/October) will be available September 1 for FREE at selected indoor gardening retail stores across the UK and on maximumyield.com Subscriptions are available at maximumyield.com/subscriptions.php

Maximum Yield UK | July / August 2011

MAX-MART

Maximum Yield UK | July / August 2011