Maximum Yield Australia - March/April 2010 by Maximum Yield

AUSTRALIA March-April 2010

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HYDROPONIC FAQS All will be answered!

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PLANT NUTRITION Seaweed, Soil and CO2 CONDUCTIVITY IN HYDROPONICS Part II

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Indoor Gardening Expo

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2010 Quebec, Canada

June 5-6

CONTENTS march / april 2010 FEATURES 20

Hydroponics and Medicinal Plants

Neem Oil: The Facts

Top 25 Hydroponic FAQS

Why You Should Use a Compost Activator

Conductivity in Hydroponics Part II

CO2 Stability and Longevity

Mobile Vegetable Garden

Seaweed: A Precious Material for Plant Nutrition

by Noucetta Kehdi by Matt LeBannister by Trevor Holt by Ferdinand Emy by Andrew Taylor

by Erik Biksa

by Michael Bloch by Luis Bartolo

DEPARTMENTS 8

From the Editor

Letters to the Editor

MaximumYield.com

Ask Erik

14 MAX Facts 16 Product Spotlight 50 Check Your Growing IQ 52 Retail Directory

54 Coming Up in May/June 54 Do You Know?

MAXIMUM YIELD Australia - March/April 2010

FROM THE editor

jessica raymond

Growing healthy and living healthy are top of mind these days, and more people are taking charge of their eating habits and their gardens. This issue is devoted to health—yours and your plants’! Natural inoculants from the sea (seaweed), soil (compost) and trees (neem) are exactly what is needed to perk up sad flora, and fight pests and disease. Good-for-you growth is also explored here with skilled hydroponics researcher Noucetta Kedhi who offers insight to homegrown medicinals like St John’s Wort (Hypericum perforatum) and the lesser known Mouse-Ear Hawkweed (aka Hieracium pilosella). Can’t get enough of Maximum Yield. Visit us online (www.maximumyield.com) for hundreds of articles on nutrition (and more), sign up to receive our monthly E-Newsletter and enter the Win Big…Grow Big online reader contest for your chance to win grow gear from Nutrifield, Flairform and yours truly!

Maximum Yield Now on Your Smartphone! Connect to MaximumYield.com instantly from your Smartphone with our all-new 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 your choice of QR software to your Smartphone, scan the QR Code and your phone’s browser will automatically launch, redirecting you to www.maximumyield.com. It’s that simple!

Jessica Raymond, Editor editor@maximumyield.com

letters to the editor Review and Praise

Aquatic Inspiration

My name is JC Gray and I recently picked up an issue of MY at a local shop. At first glance I assumed it was a catalogue or just a magazine filled with products for sale. I soon discovered that everything in your publication is very educational and informative. I find Bob Taylor’s articles very helpful. The tips he provides are an excellent blueprint for anybody working with any system to start from. I just wanted to say thanks for providing a resource filled with good nuggets! Thank you for your time, and again, excellent mag. Hope all is well at the MY headquarters.

I just started reading Maximum Yield and find it very informative and enjoyable. It brings together all the techniques and events that are happening in the industry and in everyone’s indoor gardens. I love the articles and have learned so much from just one issue. I’m not even done reading it yet! I was reading the article “Aquaponics: Clean, Green, Organic” by Dr. Mike A. Nichols (Sept/Oct 2009) and was immediately sucked in, as I’m going to be studying greenhouse production. I am extremely interested in such sustainable and ecological means of food production, with organics being a key theme as well. I love the concept and am amazed at what a little bit of ingenuity and insight can bring about. It is a technology that I am deeply interested in, and I want to learn more as I find myself drawn towards a related career in the near future. Please, send my appreciation to Dr. Nichols; he has definitely inspired me into an area of the field I love. Now I am sure of what I want to do with my education thanks to that article.

Much respect JC Gray

Simply Glowing I just wanted to start off by saying how much I appreciate Maximum Yield’s generosity. I’m totally excited to check out the Ushio bulbs I won in the Win Big…Grow Big contest, and my students will be too. I am an agriculture instructor and twice a month we hold free hydroponic classes, open to the public, on everything from nutrients to building complete hydro set-ups. This week the students are attempting to build a DIY ebb-n-grow set-up for our indoor grow room. The room so far only has one 1000 watt HPS light and a simple flood and drain table due to budget cuts within our district. If I don’t pay for it then no one gets to have hands on experience. Again thank you from the bottom of our hearts. The students and I are deeply appreciative. David Tigner

Thank you Kyler Sintich Maximum Yield reserves the right to edit for brevity.

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

MAXIMUM YIELD Australia - March/April 2010

Coming up on the Web Speed Read

1. When plants are provided with the proper CO2 concentration, they can achieve optimal photosynthesis resulting in record growth. Choose the best enrichment method for your situation. 2. The next generation of LEDs is here and they’re invading grow rooms across the globe. What makes them so powerful and efficient? Find out on maximumyield.com 3. The composition of a nutrient solution determines the health and growth rate of plants in hydroponics. But it comes down to more than just macros and micros. In fact, more than 60 elements are required for plant growth.

Behind the Lens – International Exposure Could Be Yours

Attention Photographers: Have your pictures seen internationally by thousands of readers of Maximum Yield magazine. If your photo is chosen, it will be published on the cover of Maximum Yield USA, Canada, French Canada, Australia or UK. Behind the Lens closes June 1, 2010. Flip to page 41 for more details.

When it comes to growing HUGE yields, Maximum Yield has you covered. Our Win Big…Grow Big contest is open to Australian residents with exclusive prizes from Flairform, Nutrifield and Maximum Yield. If you want to GROW BIG in 2010, this is the contest for you. Enter by April 15 at maximumyield.com/winbigAUS

Look for this symbol throughout the magazine to find more exclusive online features, and don’t forget to share your opinion by emailing editor@maximumyield.com

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

PRINTED IN AUSTRALIA 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 SALES DIRECTOR - Lisa Lambersek 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 Julie Madden - julie@maximumyield.com Gaby Morin - gaby@maximumyield.com PRODUCTION & DESIGN ads@ads.maximumyield.com Pentti Tikkanen - pentti@maximumyield.com Alice Joe - alice@maximumyield.com Wes Cargill - wes@maximumyield.com ACCOUNTING - Lee Anne Veres leeanne@maximumyield.com

UK DISTRIBUTION Growth Technology Hydrogarden Northern Hydroponic Wholesale Nutriculture UK CANADIAN DISTRIBUTION Brite-Lite Group Biofloral Eddis Wholesale Greenstar Plant Products Inc. Hydrotek MegaWatt Quality Wholesale USA DISTRIBUTION Aurora Innovations BWGS BWGS East BWGS West General Hydroponics Hydrofarm Hydro International National Garden Wholesale / Sunlight Supply R&M Supply Tradewinds

Andrew Taylor is the manager of

Matt LeBannister developed a 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.

Trevor Holt is the owner of Sydneybased Hydro Masta Pty Ltd. He has over 20 years of experience in the hydroponics industry. Their website (www.hydromasta.com.au) contains a full library of hydroponic help tips and ideas, plus their online store of over 800 quality products. Email sales@hydromasta.com.au

Erik Biksa holds a diploma in

Noucetta Kehdi is the co-founder and administrator of General Hydroponics in Europe. Noucetta got involved in hydroponics in the early 1990s and in 1996 she moved to the southwest of France where she took care of a greenhouse educating herself on all things hydroponics.

Jose Luis Pinheiro Bartolo is the president of Biobizz Worldwide Inc., a global leader in the production of hydroponic organic fertilizers and soil mixtures. He is passionate about the organic market and providing the highest service and perfectionism that comes direct from his heart and is projected to all aspects of his life

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. agriculture with majors in fertilizer sciences and crop production. Erik has amassed over 18 years of indoor gardening experience and intensive research. Since first appearing in Maximum Yield in 1999, the “Ask Erik” column and numerous articles have reached growers throughout the world.

G A R D E N I N G

VOLUME 7 – NUMBER 6 MARCH/APRIL 2010

AUSTRALIAN DISTRIBUTION Futchatec Growth Technology Holland Forge Hydraspher SupplyNet

Win Big! Grow Big! with Maximum Yield

contributors

I N D O O R

MAXIMUM YIELD Australia - March/April 2010

ASK

erik

Do you have a question for Erik? Forward it to editor@maximumyield.com with the words “Ask Erik” in the subject line, and your answer will be printed in an upcoming edition.

Good Day Erik, I just read your article about pythium, a problem I have been struggling with. My tomato crop for the last three years was wiped out and I have not had enough tomatoes to make sauce. This year, I threw out all my perlite troughs and switched to NFT. In desperation I am trying a bio-filter. I have been using the NFT for a few weeks now on a timer system of 15 minutes (on) and 45 minutes (off). Also, last summer we had 15 days of over 38°C in a row, (I reside in Adelaide, South Australia), which did not help, and the temperature of the nutrient was over 32°C, far from ideal. Regards Laurie

In Australian winters, you stand a much better chance of harvesting some nice fruits, provided the roots of the crop don’t get too cold. It’s usually much easier and less expensive to heat nutrient solutions versus cooling them. When temperatures in the reservoir get over 32°C, cropping trouble usually isn’t too far behind. Although tomatoes can be grown successfully in NFT (Nutrient Film Technique), the shallow troughs are better suited for crops with smaller root systems and fast cropping times, like lettuce for example. If you are a die-hard fan of NFT, you might continue using the system with a few modifications, including the bio-filter, provided the system and bio-filter are inoculated with beneficial microbes such as trichoderma and bacillus species. The goal here is to colonize the system with beneficial microbes, leaving no room for pythium to thrive. During the summer months, a reservoir chiller or titanium/ stainless steel cooling coils in the nutrient solution are recommended to help moderate reservoir temperatures. However, because there is not a lot of solution typically around the roots in NFT, the high temperatures will still have negative effects because the thin film of chilled solution will not be able to buffer temperatures sufficiently. Insulating the troughs and chilling the solution would help keep root temperatures more reasonable. I don’t recommend cycling the nutrient. The nutrient solution in most NFT systems is relatively static. It should be kept moving constantly to keep it aerated and to keep the roots protected, as the film of solution is the only thing standing between naked plant roots and environmental extremes. In very large commercial NFT systems, when the pump stops, the reservoir can overfill because so much solution is being circulated and contained

in so many lengths of NFT troughs relative to the holding capacity of the reservoir. If you are willing to try something new, I would recommend growing in a “DFT” system. This Deep Flow Technique works similarly to NFT, except there is a much larger chamber for roots and the depth of the solution is much greater, effectively buffering bare rooted hydroponic plants for extremes in nutrients or the environment. Essentially, for each large plant, there is about eight litres of nutrient solution. A popular brand of hydroponics system uses this principle with NFT type tubes; however, there is an adjustable overflow in each of the tubes, allowing for larger amounts of nutrient solution to surround the plant roots. For your applications, something along these lines may work out better than the thin film of nutrients that NFT systems provide. DFT systems use much higher flow and circulation rates than NFT systems, helping to saturate DO (dissolved oxygen) levels in the nutrient solution, reducing the incidence of pythium.You can construct your own DFT system out of any large sized troughs that are opaque and chemically inert, so long as you can include an adjustable overflow (to control the depth of the solution) and have a nutrient injection manifold running the length of the troughs to keep the roots and solution will aerated. If you build your own, you can insulate the troughs to keep the roots warmer in the winter and cooler in the summer. Another suggestion is to only select tomato cultivars that are documented to have a natural resistance to root pathogens such as pythium. Note that some varieties of tomato seeds will be much better suited to hydroponic cultivation versus others. Check with reputable commercial seed suppliers. Inoculating young plants with beneficial microbial solutions will also help to prevent the incidence of root diseases, and should be reapplied several times throughout the life of the crop to ensure optimal populations of beneficial root life and maintain a healthy life balance in your bio-filter. I hope this helps you out, and send us some pictures of your winter tomatoes. Cheers, Erik Biksa

MAXIMUM YIELD Australia - March/April 2010

MAX

facts

hydroponic news, tips and trivia from around the world

Third “International Conference & Exhibition on Soilless Culture” (Singapore) The Third “International Conference & Exhibition on Soilless Culture – 2010” (ICESC-2010), will take place in Singapore March 8-13, 2010, with plans to host 500-800 researchers, growers and crop advisors from more than 60 countries. Also invited are serious health-conscious consumers, educators, suppliers, food processors, environmentalists, policy makers, property developers of eco-homes, potential investors and all environment-conscious people involved in “sustainable” food networks in one way or another. The theme of this event is “Futuristic EnvironmentFriendly & Sustainable Farming Technologies for Growing Any Plants Anywhere” through hydroponics, organics and aquaponics. The aim of this event is to create awareness, exchange information and foster collaboration amongst the participants on the importance of soilless culture (hydroponics and organic farming techniques) in growing plants for food, ornamental, medicinal and industrial purposes. Please visit www.icesc-2010.com to learn more. This event is sponsored by the International Society for Horticultural Science (ISHS).

Establishing a Food Forest DVD The Permaculture Research Institute of Australia has just released a follow up DVD to “Harvesting Water.” “Establishing a Food Forest” features Geoff Lawton, managing director of The Permaculture Research Institute, presenting Food Forest systems from the beginning stages through their maturity. Geoff takes the viewer through the growth of a forest over the course of nine years and demonstrates some of the essential principles to keep forests productive. Elements covered in the DVD include: forest fundamentals; legumes; pests; fungi; weeds; kitchen gardens; swales; hardwood; mature systems and more. Video teasers can be found on YouTube. (Source: http://permaculture.org.au)

MAXIMUM YIELD Australia - March/April 2010

Gardening Apps for your iPhone The iPhone Smartphone allows users to personalize their handsets to fit their lifestyle, with applications available ranging from the essential to the exotic. Gardeners have more than 100 applications to choose from, with themes containing landscaping tips to virtual tour videos; there’s even an app that its developers claim will repel mosquitoes. All apps show up as fingertip controlled icons. Gardening apps aim to help with everything from locating supplies to fending off mosquitoes to converting cell phones into flashlights. Some are offered free, but most cost a one-time fee for downloading into your handset. Not every app remains long on virtual shelves or operates with every phone, so growers should check for availability and compatibility before ordering. Some gardening applications include: Pocket Garden (99 cents), Flowers Guide ($1.99), Botanical Interests ($5.99), Landscaper’s Companion ($6.99), Garden Supplies Store Finder (99 cents) and the General Hydroponics Nutrient Calculator (free). (Source: www.motherearthnews.com)

Victorian Wins HAL Young Leader Award Victorian vegetable farmer Rich Butler is the proud recipient of the 2009 Young Leader Award presented by Horticulture Australia Limited (HAL) in Sydney. As the managing director of his family business in Heatherton, Rich employs 70 staff and supplies major Australian supermarkets with nutrient-rich produce. In 2007 Rich attracted investment funding from Victoria’s Smart Water Fund to design and build a vegetable washing system that saves water, a system that is now available to farmers around Australia through Tripax Engineering. Rick is passionate about educating young people about horticulture, providing summer positions on his farm to school leavers each year. He also attended a Young Growers’ tour. Rick said the tour gave him confidence and developed his business skills. Rick has also contributed to the industry as a member of the Vegetable Industry Advisory Committee. (Source: www.ausveg.com.au)

2010 AUSVEG National Convention and Trade Show The 2010 AUSVEG National Convention and Trade Show, and National Awards for Excellence will take place on the Gold Coast in Queensland May 27-30, 2010. The Convention will be held at Conrad Jupiters, with the industry event combining the usual R&D focus with key topics such as marketing, the environment and packaging innovations. The event will include a trade show featuring up to 70 companies and providing attendees with a broad view of the Australian vegetable growing industry. The Convention will also be family friendly, with activities for children and special events for young growers, and will feature an exciting social program with breakfasts and information sessions featuring prominent speakers. The National Awards for Excellence will be held on the evening of Saturday the 29 of May, and the Convention will close on Sunday 30 May with a golf competition to be held at one of the Gold Coast’s stunning courses. Program and registration details will be announced shortly. (Source: www.ausveg.com.au)

Organic Farming Employment Opportunities Predicted to Rise IBISWorld predicts there will be a boom for Australian business in 2010, and the next five years will see significant growth. IBISWorld has identified a top list of industries predicted to lead the charge in the coming five years. Number one on that list is organic farming. Health consciousness and environmental awareness will drive demand for organic foods, seeing revenue grow at an average 13.4 per cent per year to reach around $760 million in 2014. As the industry expands, employment is forecasted to strengthen from 6.2 per cent in 2012-13 to 11.2 per cent in 2013-14. Job opportunities will relate to increased production, creating demand for farmers, farm hands, skilled and unskilled labourers, and itinerant workers such as pickers. While many of the jobs created will fall into the category of unskilled labour, there will also be opportunities created for ecologists, biodynamic farming specialists and researchers. (Source: www.smartcompany.com.au)

Exotic Orchids Available for Less Taiwan is putting orchids, a once high-priced product, within reach of the common consumer. The flowering of the orchid industry has been nurtured by a relationship between entrepreneurs from Taiwanese and the world. The flowers are now found for as little as $15 or less, a bargain for a plant that takes up to two years to grow and whose blooms can last as long as a month or two. Taiwan is the world’s leading producer of phalaenopsis orchids, one of the most popular varieties. A couple of decades ago an orchid plant could cost as much as $2,000. Taiwan’s hot and humid

climate is perfect for early-stage orchid growth. But the “spiking” process—the budding and blooming of orchids—needs cooler temperatures, so the young plants are shipped to cooler, coastal locations, where the climate is wellsuited for the blooming of orchids. Farmers ship orchids in sterile sphagnum moss, a process that produces hardier baby orchid plants. Shipping orchids embedded in moss dropped transportation costs from about $1.50 per plant to 20 cents. MY (Source: http://fwix.com)

MAXIMUM YIELD Australia - March/April 2010

PRODUCT spotlight

ask for these exciting new products at your favourite indoor gardening store.

House & Garden Bud-XL House & Garden Bud-XL extracts sugars from the leaf of the plant and transfers them to the fruit. The fruit is made sweeter with improved flavour. Bud-XL also increases the size and robustness of the flower, resulting in increased fruit production and greater yields. Start adding Bud-XL to the nutrient after the first flowers are formed. This is the period that the big bract loses its function. By adding Bud-XL you ensure that the plant’s energy is no longer used for keeping the bract, but is directed to forming flowers and fruits. Use in conjunction with Shooting Powder for best results. Use Bud-XL during the flowering period. Available in one litre and four litres. Bud XL is available from local indoor garden shops now.

Aminozym - Organic Root Stimulator from Cash Crop Aminozym is an organic-based root and grow stimulator and tonic. Aminozym promotes leaf, stem and enzyme production, guaranteeing the best start for young plants. This root stimulator consists of amino acids, natural flowering hormones, vitamins and organic macro and micro elements from seaweed kelp and vegetable matter. It ensures a faster growth rate, larger root mass, improved resistance to disease and increased production of the plant’s natural oils and resin. Use Aminozym from the start, until the end of the second week of bloom. Aminozym guarantees the fastest, healthiest and heaviest harvests. Visit your local grow shop to learn more.

Grow Indoors with the HomeBox Modular Greenhouse Hydro-Logic Upgrades the Stealth-RO The Stealth-RO100 and Stealth-RO200 have been the industry leading reverse osmosis filters for several years, offering quality and performance to hydroponics and organic soil growers. Hydro-Logic is proud to announce some important upgrades to both systems. The addition of an optional flow restrictor will bring the already efficient 3:1 ratio down to a 2:1 ratio of drain-to-product water. Both units come plumbed with the standard restrictor (3:1 ratio), saving an additional 33 per cent of drain water. We have also included a pre-plumbed pressure gauge, allowing users to monitor system performance and diagnose low pressure and low flow problems. Another standard upgrade is the green certified coconut carbon block filter. This is the world’s first eco-friendly carbon filter and a Hydro-Logic exclusive product. Look for the newly redesigned retail box plus upgraded instructions. HydroLogic brings you all these great upgrades at no increase in price. Pure water’s not magic, it’s logic. Contact your local indoor gardening retailer to learn more.

MAXIMUM YIELD Australia - March/April 2010

The HomeBox Modular allows growers to fully customize and adapt the size and shape of their HomeBox to their needs. Hydroponic systems have been a popular choice for those with the room to set up a permanent garden, but many have discovered that a contained, movable environment that can fit in a space as small as a closet or as large as a basement or garage may be the best option. Visually appealing and long-lasting, the HomeBox Modular is washable, air tight, lightweight, customizable and affordable. The box can be set up by most users in less than one hour without any tools. Additionally, the HomeBox is made from PE, not PVC, which means the grow box will not create dioxin, a hazardous gas created by PVC when it is heated. The HomeBox Modular is now available in Australia. For more information, contact your nearest hydro retailer.

GHE Tripack Starter Kit - Compact, Economical, Comprehensive Are you starting a new garden? General Hydroponic Europe’s latest product, the Tripack Starter Kit, is exactly what you need. The Tripack offers four options: 1. The Flora Series Tripack: three FloraGro (½ litre), FloraBloom (½ litre) and FloraMicro (½ litre). 2. The FloraNova Tripack: two FloraNova grow and bloom (½ litre) and Ripen (½ litre). 3. The One Part: two Total Grow and Total Bloom (½ litres) and Ripen (½ litre). 4. The FloraDuo Tripack: two FloraDuo grow and bloom (½ litre) and Ripen (½ litre). FloraDuo is Dr. Herrmann’s latest innovation and will be available before winter 2010. Each Tripack contains a free pH test kit (good for more than 400 tests), and 25 grams of pH Down in powder form (a highly soluble and concentrated pH regulator). With the Tripack you have enough nutrients to complete a cycle of plant growth. For more information inquire with your GHE retail supplier.

Bloombastic Box for Beginners Atami makes it very easy for beginners to grow their very best. The Bloombastic Box for Beginners is made for a square metre garden, and includes Terra Leaves (one litre), Terra Max (one litre), Bloombastic (250 millilitres), ATA-zyme (100 millilitres), Root-c (100 millilitres) and a Bloombastic grow scheme. In addition to the Bloombastic Box for Beginners, there are two other boxes in this successful series: the Ata Organics Box and the Atami Box. More information is available at indoor gardening retail stores.

MAXIMUM YIELD Australia - March/April 2010

PRODUCT spotlight

ask for these exciting new products at your favourite indoor gardening store.

High Quality Hydroponics Fertilizer Shiva A&B Cash Crop Shiva A&B is a two part, high quality, hydroponics fertilizer that is designed to be used in the grow and bloom cycle, in any medium (soil, hydroponics, coco peat). Shiva A&B are made from the most expensive and purest raw material, guaranteeing the fastest growth rates and heaviest yields. It’s simply the easiest to use and the best hydroponic nutrient on the market today. Since Shiva A&B are made from the best raw materials, they will never clog your vat, pump or irrigation system and the EC will always remain stable. Available in one litre, four litres, eight litres and 16 litres. Ask for Shiva at your nearest hydro retailer.

MAXIMUM YIELD Australia - March/April 2010

House & Garden Shooting Powder The secret of every successful grower is Shooting Powder. This sparkling bud expander is the absolute best in the field of flowering simulators. It gives visible results, can be combined with all base nutrients, is packed in a handy sachet, simple to use and has been extensively tested in the House & Garden’s research and development centre. Try it once and you will come back for more. This flowering booster starts a new flowering cycle after the regular flowering phase, significantly increasing the fruit’s weight. The extra yield after applying this nutrient additive will surprise you. It actually creates a new layer on top of the existing fruit. Output increases of over 20 per cent can be reached this way. Shooting Powder is available now from indoor gardening retailers.

House & Garden Top Booster House & Garden Top Booster is an excellent flowering stimulator, which acts on the basis of potassium, phosphorus and Eddha-Fe (iron). These elements are important for the plant’s flowering; potassium for the beginning of the flowering stage and phosphorus for the proper development of fructification, while the Eddha-Fe additive ensures a better colouring of the leaves. Top Booster creates an optical drought giving the plant the impression that the last phase of its life cycle has started. To ensure its survival, the plant will then begin forming flowers and fruits to reproduce. Add Top Booster for two to three days and then return to the usual nutrient composition. The plant will continue to form fruits and flowers. As this aspect of the final phase of the plant’s cycle starts earlier, the fruits and flowers have more time to become larger. Never use Top Booster in combination with PK 13-14, Top Shooter or Shooting Powder. Top Booster is available now from your local hydroponics retailer.

Alg-A-Mic from Biobizz Alg-A-Mic is an OMRI listed, high-grade organic seaweed concentrate extracted through cold-press. It contains a high content of trace elements and hormones of vegetable origin, naturally occurring amino acids and vitamins that cater to the whole spectrum of a plant’s needs. Alg-A-Mic is a bio-stimulant to be used sparingly. It can be used as a soil drench, an additive for hydroponic nutrients or as a foliar spray for instant vigour in any stage of plant growth. It has gained popularity for its effectiveness among bonsai growers in the USA and Japan. Alg-A-Mic can be taken in by the leaves through sprayers and with water directly applied to the root-zone. Healthy plants grown with Alg-a-Mic are less likely to suffer from deficiency and temperature fluctuations. Available in 500 millilitres, one litre, five litres and 10 litres. Check out a hydro retailer near you to learn more about Alg-A-Mic and the Biobizz product line. MY

MAXIMUM YIELD Australia - March/April 2010

by Noucetta Kehdi

x R

Hydroponics and Medicinal Plants

For the hobby gardener, growing hydroponically offers

enormous opportunities and sometimes unsuspected alternatives. When you start a hydroponic garden with the proper nutrients you are generally stricken by the rapidity of growth and the vigour of your plants, not to mention the profusion and generosity of your yields! Often this leads to unexpected vocations. The marriage of medicinal plants and hydroponics may sound odd, and yet, during my many years of research on hydroponically-grown plants, one of my goals was to attain unequalled growth allied with excellent crop quality and high “essential” content. Another objective was to offer new alternatives to small commercial growers, associating them to successful and economically independent ventures. During these years I came across a large variety of plants, and nearly each time the results were astounding. Plants were plentiful, beautiful and healthy. They smelled sweet and tasted great; they were rich in active principles.

MAXIMUM YIELD Australia - March/April 2010

So quite naturally a section of my studies was directed to culinary and therapeutic plants. But if it was easy to choose the right culinary plants (basil, sage, mint, parsley, chives, etc), it was much more difficult to determine which medicinals would be interesting to cultivate. The idea was to establish a list of high value cash crops that could grow in my greenhouse in France, analyse them and eventually suggest them to potential smallscale commercial growers. In order to be sure of my choice I contacted the University of Toulouse, France and it’s Faculty of Pharmacognosis. It was important that once analysed the hydroponically grown crops would be truly compatible with the pharmacopoeia’s requirements. The faculty suggested a few plants from which I chose Hieracium pilosella and Hypericum perforatum. Both of them had value and were excellent candidates for economical, practical, and of course, for medicinal purposes.

Mouse-Ear Hawkweed, a yellow-flowered species of Asteraceae, is native to Europe and Northern Asia.

Hieracium pilosella

Hieracium pilosella (also called Mouse-Ear Hawkweed,) is a soil-cover, rampant (30 centimetres maximum) colony-forming plant. It is a perennial, stoloniferous herb whose rosettes form dense, prostrate mats. Each rosette produces a single, lemon yellow flower between May and September. Seeds stay on the plant until end of winter. Leaves vary in size according to habitat, from two by 0.5 centimetres in drier, less fertile sites to 10 by two centimetres in moister, more fertile sites. The under-surface of the largely smooth leaves has a dense cover of white hairs. Hieracium pilosella has been used since the ancient times for its several medicinal qualities, and mainly as a â&#x20AC;&#x153;cleaner.â&#x20AC;? In the past the sap was used to accelerate the cicatrisation of internal and external wounds and to relieve kidney malfunctions. Today it is still used. It is known as an astringent, with strong diuretic, depurative, and antibiotic properties. It is often used to eliminate superfluous water from the body and increases the secretion of the gall bladder. All parts are used. The most common way of preparing it is by infusion of the fresh leaves for internal cleansing. An old recipe says: 100 grams for one litre of water, infuse for 15 to 20 minutes and take three cups/day. MAXIMUM YIELD Australia - March/April 2010

Hydroponics and Medicinal Plants

For external use crush the fresh leaves. They act as a detergent and help heal atonic wounds. (See notice at the end of the article). Hieracium easily adapts to all substrates and is quite easy to grow. But it has two characteristics that make it less attractive to traditional soil growers:

1. It is allelopathic, which means invasive. The active principle

in a plant is the original inherent constituent, which characterises a substance, and gives it its essential properties: power to heal, to cure, to nourish, etc. Most often people will think that an active principle is only characteristic to medicinal plants. But it is not. Fragrance and flavour are the results of active principles too; the sweeter the smell or the stronger the taste, the higher is the content in the correspondent active principles. Young plants form dense mats in open spaces through vegetative development and extend quite rapidly. Their roots emit a substance inhibiting neighbouring root growth, which makes it a true intruder in some countries. Indeed it is recorded as a weed and even forbidden to import in some countries like Australia, or Canada because, when conditions are met, it competes with neighbouring plants to the point of invading the soil completely and threatening local biodiversity. It is a native of England and grows well in the rest of Europe, especially in areas like the dry prairies of the Pyrenees. It forms a very pleasant mat to walk upon, and makes an excellent candidate for lawns in poor soil.

While being an obstacle for soil growers, these two disadvantages make Hieracium pilosella a perfect candidate for hydroponics. Indeed, the plant is cultivated in enclosed growing modules and cannot spread out. No need for harvesting machines; in hydro your plants grow on high beds making harvesting a much more practical process. They grow in clean and easy to wash-off substrate like clay pellets, which eliminates the cost of cleaning and sorting. Last but most important, in hydroponics you increase the quality and quantity of your yields, as well as their content in active principles, especially when you use the 2. It is a rampant, which has two disadvantages when harvesting: right nutrients. • When in contact with soil, the blades of the harvesting maI began testing Hieracium pilosella with the understanding chines become blunt. They have to be regularly sharpened that the faculty in Toulouse would analyse the harvest and give or replaced, and become an economical setback. me its conclusions about the quality of the plants compared to • The harvest is dirty, full of soil and debris, and has to be soil-grown, and their content in active principles. cleaned before starting proper processing, which represents I started the Hieracium from seeds in a tray with a mix of another economical burden. perlite and vermiculite. As soon as they became vigorous young seedlings, I transplanted them into a one metre squared drip feed hydro system with a mix of small and medium size rocks for best adherence to the root system. I used professional grade nutrients and set the nutritive solution around EC 1.0 and pH 5.8 – 6.2. The plants developed quite well and rapidly increased in size with leaves measuring 10 by three centimetres minimum. In no time they covered the whole area. Maintenance was minimal, just cleaning the dead leaves from time to time. To respond to the criteria of the analysis I picked part of the plants before flowering and the other after flowering, dried them as requested and sent them to the laboratory. The results came back quite encouraging. “Batch corresponds to Pharmacopoeia, presenting a high level of tracers (active substances),” iracium H f o ty was the conclusion of the laboratory’s report. re vered The enti nnial, is co re e p The macroscopic and microscopic identifications, as a , a pilosell s. hitish hair w r, well as the mineral content of the crop, were consistent la u d in glan

MAXIMUM YIELD Australia - March/April 2010

Widely known as an herbal treatment for depression, Hypericum perforatum (St. John’s Wort), has long been enjoyed as an herbal tea.

with the required norms of the soil-grown control. The dosage showed that the hydroponically grown Hieracium contained 4.24 per cent of active principles compared to 2.5 per cent for the control! This first analysis boosted my spirits, and opened a large field of investigation and research for me. Once again I had the confirmation that with the proper technology and products I could increase the volume of production, and get the assertion that those products were appropriate for human consumption, and fit to be used for therapeutic applications.

Hypericum perforatum

My second test was with Hypericum perforatum (or “St. John’s wort”), a long-living plant, which spontaneously grows in most uncultivated areas. It is called “perforatum” because the leaves, when held to the light, show little translucent dots that look as if they were perforated. In reality the dots are not holes, but vesicles of colourless essential plant oils and resin. Hypericum contains lots of active ingredients with therapeutic virtues, including hypericin and hyperforin. In summer it blooms into bright yellow-orange flowers with petals peppered with black dots. These dots, when rubbed between the fingers become red. Many herbalists say that the translucent perforations, and the black-red dots contain the most active medicinal qualities. (www.hypericum.com) Hypericum perforatum, is an exceptional plant. In the Middle Ages it was considered magical, capable to chase malicious spirits away. It was mainly employed to treat nervous diseases. It was used as “red oil” to cure burns. This consists in macerating the flowers with olive oil in a sunny spot for a few weeks. Once the oil becomes red, it is filtered and kept aside to use on all kinds of burns and bruises. ** Abandoned for a few decades, Hypericum was rediscovered thanks to modern research that put into perspective its

MAXIMUM YIELD Australia - March/April 2010

Hydroponics and Medicinal Plants

Johnâ&#x20AC;&#x2122;s d plant, St. te ia c e r p p w a A highly oned for a fe d n a b a y ll a tu d for Wort was ac rediscovere g in e b e r fo s. decades be ve propertie ti a r u c s u o r its nume

numerous curative properties. It is today a highly appreciated plant, and you can find it on the shelves of most organic stores and pharmacies worldwide. Hypericum is generally used to treat moderate depression, anxiety and sleep disorder. It seems to have several other virtues and research is still conducted as to the extent of its possible applications. With the rising general interest for the plant, demand is increasing. Hydroponics of course could represent an excellent alternative, but again only if you make sure that your crop satisfies strict therapeutic specifications. I started Hypericum perforatum in a row of hydro pots, using a series of professional nutrients. Again plants grew very rapidly and bloomed at the end of June. I picked the flowers and fruit in the beginning of summer, a few days after the solstice; I dried them, and sent them again to Toulouse. The results that came back were equally as impressive as they were for the Hieracium pilosella. The harvest was separated in two groups, one with only the flowering tops, and one with the fruits. They were compared with a batch of wild Hypericum grown in soil in the region of Toulouse, as a control. The analysis concluded that the hydroponically grown batch entirely complied with the list of requirements of the pharmacopoeia. The

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content in total hypericines (the most important active substance in Hyperium perforatum) was higher: 0.12 per cent for the soil control, 0.19 per cent for the flowering tops and 0.13 per cent for the fruits, the minimum required by the pharmacopoeia being 0.8 per cent. The plants passed the tests brilliantly. I could now draw my own conclusions: the cultivated medicinal plants fully complied with therapeutic requirements, but also contained more active principles than usual. I had the confirmation that these products could be grown for medicinal purposes. I am not sure how much demand already exists for Hieracium pilosella, but the plant has potential and could be commercially exploited. I know that there is definitely a market for Hypericum perforatum, and there are many more possible candidates to come. MY

Note: ** Although plants are natural, they must not be used without the right knowledge or advice. So when you find them on the shelves, and if you grow them, make sure to ask for advice before ingesting them, as some of them can be terribly dangerous without the proper knowledge.

Learn about active principles and Noucettaâ&#x20AC;&#x2122;s furthur research on Chrysanthemum parthenium on maximumyield.com

Neem Oil S T C FA THE

by Matt LeBannister Neem oil is a botanical product derived from pressing the seeds of the Indian Neem tree and it functions as an insecticide as well as a plant fertilizer. However, the effectiveness of neem oil as a pesticide or fertilizer is often up for debate. Many gardeners swear by its ability to keep pest populations under control and its ability to eliminate the pests entirely. Others choose to use chemical pesticides claiming neem oilâ&#x20AC;&#x2122;s active ingredient azadirachtin takes too long to take effect. The idea of using neem oil as a fertilizer has been the common practice of gardeners from India and Pakistan for centuries. Neem cake, made from the pressed fruit and seeds used to extract the oil, is also gaining popularity as a fertilizer.

MAXIMUM YIELD Australia - March/April 2010

Here are the facts When used as a pesticide the ingredient that affects the insects is azadirachtin. Azadirachtin confuses growth hormones causing insects and eggs to never reach maturity. The catch is that neem oil is not as effective against adult insects since they are already mature. The fatty acids in the oil can clog the membranes of soft skinned insects such as aphids and kill them as a result. To destroy pest populations, neem oil must be sprayed on the affected plants two times a week for at least two weeks. This will help ensure each successive pest generation will be diminished until there is none left. Mix neem oil in water at a rate of five to 10 grams per litre of water. Neem oil can also be poured on a cloth or paper towel and manually applied to the leaves of the plants. This can be especially effective against scales. Neem oil can be used against a variety of pests including, but not exclusive to, spidermites, aphids, scales, thrips and mealy bugs. The one downside to applying neem oil is that it will also kill any beneficial insects in your garden. Neem oil and neem cake also improve the quality of soil. The recommended dilution rate for neem oil as a fertilizer varies from two millilitres to 15 millilitres of neem per litre of water. Experiment by starting with small amounts and working your way up, checking the EC and pH levels often. One of the ingredients prevents nitrogen-fixing bacteria from converting the nitrogen in the soil into gas, thus allowing more nitrogen to be available to the plant. Neem oil can be effective as a pest control or fertilizer when applied properly. But donâ&#x20AC;&#x2122;t take my word for it. Try it for yourself and give Maximum Yield your feedback.

Careful consideration should be given when using neem oil as a pest control. While it is quite effective against a variety of pests such as spidermites, aphids and gnats (above), it doesn't discriminate against beneficial insects, such as ladybugs (top).

Neem oil and neem cake can make great natural fertilizers. Both contain many different macro and micro-nutrients. According to AgroGreen Canadaâ&#x20AC;&#x2122;s website, the average sample of neem oil will contain the following: Azadirachtin - 1800 ppm Total Nitrogen - 1.20 per cent by mass Phosphorous - 0.07 per cent by mass Potassium - 0.01 per cent by mass Magnesium - 0.03 per cent by mass Copper - 10 ppm Magnesium - 0.40 Zinc - 20.00 ppm Iron - 14.00 ppm

MAXIMUM YIELD Australia - March/April 2010

25 TOP

Hydroponics FAQs by Trevor Holt

Hydroponics is so advanced that at times it can feel like information-overload. This article provides an opportunity to step back and refocus on the simple tasks that will help your garden grow.

Q. What pH should I maintain?

Q. Does the nutrient solution need to be heated?

A. The pH should be kept between 6.0 and 6.5 with 6.3 the ideal range.

A. It is best to maintain nutrient solution temperatures between 18°C and 22°C. Temperatures below 18°C will cause growth to slow. It is necessary to add heat to your grow room in cooler seasons.

Q. How long should I run my lights? A. Lighting hours depend on the plant’s growth phase. Seed raising = 24 hours per day Cutting phase = 18 hours per day Vegetative phase = 18 hours per day Flowering phase = 12 hours per day

Q. What causes the tips of plants to burn? A. This can be caused by too much fertilizer (too high CF), too much salt in the water, not enough water, lights placed too close to the plants or poor air movement in the grow room. Certain nutrient deficiencies can also cause tipburn. Use a well known brand of nutrients, and if in doubt, change the solution. 30

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Q. What causes plants to die? A. There can be a number of reasons for this. First you must eliminate the obvious elements that could be causing death, like lack of water or high temperatures. Root diseases like pythium are quite common and can cause sudden death of plants as well as low yields and a complete collapse. Microbial cleansers have been proven very useful in the treatment of root zone problems. As a preventative measure the risks can be reduced by way of friendly bacteria, which break down the dead root matter and convert it into useable compounds that the plant can absorb.

Q. Why do plants stretch? A. Plants stretch when the light is insufficient or humidity is too high. Lack of ventilation is normally the cause of high humidity.You should always have the air coming in the same as the air going out at the same rate.You need at least 20 to 30 air changes per hour.

Q. What humidity should I maintain? A. Humidity is best maintained at 50 per cent in the centre of the plant canopy, although between 40 per cent and 60 per cent is acceptable. Too high a humidity runs the risk of disease and stretching.

Q. What temperature should the growing room be? A. Room temperature needs to be maintained at around 25°C in the vegetative phase and a couple of degrees lower in flowering though anywhere between 22 and 28 is acceptable.

Q. How much ventilation is necessary? A.Ventilation needs to be enough to maintain a temperature of about 28°C and a humidity of about 50 per cent in the centre of the plant canopy. Generally it is better to have too much than too little ventilation.

Q. What is the best hydroponics system? A. The success of any system will depend on the management. The best results are often achieved with the simplest of systems.

Q. What is the best medium? A. As with systems, there is no “best” medium. Each medium requires different management, but expanded clay tends to be easy to manage and very effective, with good moisture retention and good drainage.

While there are many good choices for hydroponic mediums, expanded clay continues to excel at drainage and moisture retention.

MAXIMUM YIELD Australia - March/April 2010

Top 25 Hydroponics FAQs

Q. Should I use EC and pH metres? A. Trying to run a hydroponic system without metres is very difficult, making it hard to achieve optimum results.

Q. How often should I dump my nutrient solution? A. There is no hard and fast rule on this one. Generally the cheaper nutrients require dumping more often than the better ones. The size of the reservoir relative to the number of plants is also important. Using quality nutrients would only require dumping every two weeks, although most experienced growers dump every week to keep water quality at a premium.

Q. What size reservoir should I run? A. For ease of control, use a minimum of 45 litres per square metre of growing area, as less than this requires frequent adjustments. A rule of thumb is at least 50 per cent should remain in the tank during irrigation.

Q. What is the best nutrient to use? A. There are a number of good nutrients on the market. Unfortunately there are also many nutrients which are cheaply made and donâ&#x20AC;&#x2122;t do the job properly. Any well established brand, which uses technical grade mineral salts should be suitable.

Q. Is it necessary to aerate the nutrient solution? A. Aerating the nutrient solution is a good idea. It guards against stagnant water, helps mix the nutrient and stimulates root development.

Q. How long should it take for clones to strike roots? A. The time taken to strike roots on clones varies according to the time of the year and the health of the clones. About five to 12 days is normal. Using rootzone accelerant in the tank and stress guard as a foliar spray will increase the strike rate significantly as well as the subsequent health of the plant.

Q. What is the best water to use? A. The best water will have low salts and no contaminants. Household tap water should be okay; if you can drink it yourself, it is should be satisfactory for your plants. The best way to test is to sample some, and if you get a significant CF reading it may be wise to invest in a counter top water purifier.

Q. What is the purple colour on the plant leaves? A. The purple colour is a pigment called anthocyanin. It is produced by plants which are growing under some stress. It is often caused by cold growing conditions. It also often happens during flowering and is a deficiency of either potassium or phosphorous, so you will need to increase your nutrient levels.

Q. How much light should I use? A. The optimum amount of light to use is usually between 400 and 600 watts per square metre of growing area; the more light the better.

MAXIMUM YIELD Australia - March/April 2010

Q. Why are my plant roots brown? A. Brown roots are usually those that have been attacked by disease, probably “pythium.” Using a microbial cleanser will be of great assistance and usually eliminates the problem. Normally, healthy roots should be white with fine hairy air roots.

Q. My plants have very small bugs which spin webs. What are they? A. These are troublesome pests known as red spider or “spidermite.” They can cause severe damage by destroying the plants chlorophyll, and the plants should be treated as soon as possible.

The troublesome spidermite.

Q. Are there any other pests that attack my plants? A. Whitefly, thrips and caterpillars can also be troublesome. Proprietary remedies are available for specific pests.

Q. What is the brown rotting on the flower buds? A. This is probably a disease called botrytis (grey mould), best controlled by maintaining optimal humidity. Regular use of a friendly bacteria/fungicide will help control botrytis as well as many other fungal problems.

Q. There are small black flies around the root system of my plants. Are they a problem? A. The flies are probably scarid flies (fungus gnats). Their larvae can cause severe damage to feeder (hairs) on roots. Treat them with a suitable product like a bacterial inocculant or soil drench. MY

Maintenance charts for seed germination, cuttings and the flowering cycle are available on maximumyield.com

MAXIMUM YIELD Australia - March/April 2010

Why You Should Use a Compost Activator by Ferdinand Emy

Composting can provide many benefits, but when you are first getting started, it can be somewhat confusing. Compost activators contain a combination of nutrients and micro-organisms. They are typically available in powder form and poured into holes within the compost pile. So what are compost activators, also referred to as compost inoculates, and how can they benefit your compost?

Herbal compost activators may contain such ingredients as dandelion, chamomile, yarrow, oak bark, nettle, valerian and honey. The pile will then be efficiently composted within one to three months, depending on the time of year. There are also other types of natural compost activators that are produced from other materials such as comfrey leaves, chicken manure and grass clippings.You can choose to add compost activators to your compost pile when you first begin in order to give it a kick start or you can add compost activators in at different times of the year as they are needed.

MAXIMUM YIELD Australia - March/April 2010

Generally, compost piles will take some time to decompose naturally. This is something that you want to avoid, thus the need for the compost activator. Compost activators are usually just added directly on top of the other compost scraps. One element that you will need to understand is they can also be used to provide the heat activation that the compost pile needs when the weather is below 10Â°C. Herbal compost activators are completely natural and work efficiently and quickly. The ingredient mix in herbal compost activators creates a compost pile that has a sweet scent to it. While you could certainly allow your compost pile to decompose on its own without adding in compost activators, you run the risk of attracting odours and flies as well as other pests to your compost pile. Compost activators work by providing the nitrogen that a compost pile typically lacks naturally. Nutrients, including potassium, may also be added to these compost activators. The holes are then filled back in. They are added to the compost pile for the express purpose of speeding up the breakdown of the scraps in the pile. Other options for compost activators include fish, cottonseed, alfalfa MY meals and bone meal.

About the Author Ferdinand Emy is the author of â&#x20AC;&#x153;The Keys to Great Composting.â&#x20AC;? This book teach you how a compost activator works and how it will tremendously enhance your composting experience today.

MAXIMUM YIELD Australia - March/April 2010

Using Conductivity to Control Nutrient Concentration Part II by Andrew Taylor: Chemist for Flairform

It is important to control the concentrations of hydroponic nutrients. Burning of roots or foliage can occur if levels are too high. If the concentration is too low then deficiency symptoms will occur. The concentration of nutrients and additives is usually set by the manufacturers who recommend volumetric dose rates of, for instance, four to five grams per litre. Nutrient labels often list dosage rates in terms of both volume and EC. However, for the main inorganic nutrient, a conductivity (EC) metre* is a helpful dosing aid. *Also includes cF and TDS metres

MAXIMUM YIELD Australia - March/April 2010

“Without calibrating your EC metre, you can’t confidently use the EC recommendations supplied on nutrient product labels.” Uses of EC metres 1. EC metres gauge the total concentration of salts in the nutrient solution. They are useful for setting the target EC (table one ‘a’) when a nutrient batch is first made - see step four below. Note:

EC metres will not detect organics like vitamins and hormones. 2. They are also useful for maintaining the target EC as nutrient and water is consumed in re-circulating systems. However, because both good and bad salts are included in the reading, re-circulating nutrients must be frequently dumped because of the likelihood of toxic levels of bad salts (chloride) present, and an imbalance of good salts.

Units EC measurements are typically stated as mS (cF and ppm are common, but unequal alternatives). For example, distilled water and organics have an EC of zero mS. Mature flowering plants, however, typically require a nutrient solution EC of around two mS. Obtaining conductivity readings Step 1. Make sure the metre is calibrated. Step 2. Remove a representative sample from the nutrient reservoir: • For re-circulating systems ensure the reservoir is always filled to the same volume. If the reservoir is only half full, then the conductivity reading will be twice as high as what it would be when full. • Stir the nutrient thoroughly prior to sampling. • Ensure the sampling container is clean. Step 3. Rinse electrode in distilled water before immersing in the sample. Wait a few minutes* before switching the metre on and recording the EC. *Wait longer if the sample’s temperature is significantly different from 25°C. Step 4. • If the EC is below target, add nutrient to the water until correct (to calculate this refer to table two). When making MAXIMUM YIELD Australia - March/April 2010

Using Conductivity to Control Nutrient Concentration - Part II a new batch of nutrient, use the label’s volumetric dose rate as a guide. • If the EC target is exceeded then add more water. To calculate this, refer to table three. Refer to table one for commonly recommended EC levels for the main stages of growth. These levels are suitable for the majority of plant types (for specific plants see table one ‘b’). Within certain limits, there is no need to be precise with EC levels because plants will generally only consume what they need. Most species will tolerate being above or below the recommended value by at least 10 to 20 per cent.

Table 1b. Recommended nutrient strength** for specific plant species Vegetables

Artichoke 1.0-2.0mS Asparagus 1.5-2.0mS Barley 1.5-2.5mS Bean 2.0-3.0mS Beetroot 2.0-3.0mS Broccoli 2.5-3.0mS Brussels Sprout 2.5-3.0mS Cabbage 2.5-3.0mS Capsicum 2.0-2.5mS Carrot 1.5-2.0mS Cauliflower 1.5-2.0mS Celery 2.0-2.5mS Cucumber 2.0-2.5mS Eggplant 2.5-3.0mS Endive 2.0-2.5mS Fodder 1.5-2.0mS Garlic 1.5-2.0mS Leek 1.5-2.0mS

Fruit

Banana 2.0-2.5mS Black Currant 1.5-2.0mS Blueberry 1.5-2.0mS Melon 2.0-2.5mS Passionfruit 1.5-2.5mS Paw Paw 2.0-2.5mS

Herbs

Basil 1.0-2.0mS Chicory 2.0-2.5mS Chives 1.5-2.5mS Fennel 1.0-1.5mS Hops 1.5-2.5mS Lavender 1.0-1.5mS Lemon Balm 1.0-1.5mS Marjoram 1.5-2.0mS

Flowers crops

African Violet 1.0-1.5mS Aster 1.5-2.5mS Begonia 1.5-2.0mS Canna 1.5-2.5mS Carnation 2.0-3.0mS Chrysanthemum 1.5-2.5mS Dahlia 1.5-2.0mS

Lettuce 1.0-1.5mS Okra 2.0-2.5mS Onion 1.5-2.0mS Pak-Choi 1.5-2.0mS Parsnip 1.5-2.0mS Pea 1.0-2.0mS Pepino 2.0-3.0mS Potato 2.0-3.0mS Pumpkin 2.0-2.5mS Radish 1.5-2.0mS Spinach 1.5-2.5mS Silver Beet 1.5-2.5mS Sweet Corn 1.5-2.5mS Sweet Potato 2.0-2.5mS Taro 1.5-3.0mS Tomato 2.0-3.0mS Turnip 2.0-2.5mS Zucchini 2.0-2.5mS Pineapple 2.0-2.5mS Red Currant 1.5-2.0mS Rhubarb 1.5-2.0mS Strawberries 2.0-2.5mS Watermelon 2.0-2.5mS

Mint 2.0-2.5mS Mustard Cress 1.0-2.5mS Parsley 1.0-2.0mS Rosemary 1.0-1.5mS Sage 1.0-1.5mS Thyme 1.0-1.5mS Watercress O.5-1.5mS

Ferns 1.5-2.0mS Fichus 1.5-2.5mS Freesia 1.0-2.0mS Impatiens 1.5-2.0mS Gladiolus 2.0-2.5mS Palms 1.5-2.0mS Roses 1.5-2.5mS

** This is a guide only. Values are represented as EC (mS/cm2 abbreviated to 'mS'). Generally use the lower value for run-to-waste systems (e.g. coco fibre, rockwool, soil) or where day air temperatures are above 30°C/86°F. Use the higher values when growing in re-circulating systems (e.g. NFT, Flood &Drain) where day air temperatures are below 30°C/86°F.

MAXIMUM YIELD Australia - March/April 2010

“Electrode contamination causes a loss in sensitivity and accuracy, so clean regularly for maximum performance.” Step 5. When complete, rinse electrode with distilled water. Store the electrode in distilled water when not in use.

Calibrating EC metres Unless an EC metre is calibrated, you cannot confidently use EC recommendations like those supplied on many nutrient products. Calibrating cross-checks the metre’s accuracy against a solution of known conductivity called a conductivity standard. To calibrate, either refer to your metre’s instructions, or do the following: Step 1. Rinse electrode in distilled water then gently wipe with a tissue to remove excess water. Immerse electrode in 2.76 mS/cm (cF 27.6) Conductivity standard* for five minutes, then calibrate the metre so that it reads the following: • For conductivity metres calibrate to 2.76 mS/cm or cF 27.6. • For TDS metres calibrate to 1800 ppm (or as directed). *Note: To prevent contamination of the stock solution, decant a portion into a smaller container and discard once used. Step 2. Remove electrode from conductivity standard and rinse with distilled water. The metre is now ready to be used. Maintaining EC electrodes Cleaning conductivity electrodes: Conductivity metre electrodes normally become coated with impurities. The degree to which this occurs will depend upon the nature of the samples being tested, and whether or not the electrode is rinsed with distilled water and properly stored after each use. Electrode contamination causes a loss in sensitivity and therefore accuracy. Regular cleaning will maximize electrode performance and ensure a longer working life. Note that when testing nutrient solutions, both organic and inorganic contaminations tend to co-occur. It is, therefore, important to use an all-purpose cleaner. Be aware that most cleaners usually only remove inorganic contaminants. Store the electrode in distilled water when not in use. This will help prevent salt build-up which tends to encrust the electrode if left to dry out. Purchasing a conductivity metre Popular styles of conductivity metres range from the more

MAXIMUM YIELD Australia - March/April 2010

Using Conductivity to Control Nutrient Concentration - Part II expensive laboratory grade to the cheaper, pocket sized versions. The following specifications are important considerations: • Ability to produce readings in Siemens (mS) or cF. Avoid metres that will only yield TDS (ppm). • Calibration facility: Helps ensure accuracy even when electrodes are not performing to original specifications due to electrode contamination, physical damage, etc. • Housing that is both waterproof and floats helps protect against accidents and mishandling. • Temperature compensation: A built-in temperature sensor allows the metre to adjust readings to display what it would be if the temperature was at 25oC. • Long battery life with auto-off feature to prolong battery life.

“TDS is a derived value and employs guesswork of the composition of the solution.”

“Many high phosphate flowering additives will require a conductivity factor of 1,100 mS/cm.” Limitations of TDS (ppm) EC readings can be used to determine the approximate TDS (total dissolved salts) of various solution types. However, growers must be aware of the limitations with this method. TDS is calculated by multiplying the EC by a conductivity factor; this derives the approximate concentration of salts in ppm (or mg/l). However, because the EC is dependant on the nature of the salts present, we must use a specific conductivity factor, which matches the type of solution being tested. For example: Soft natural waters*: Multiply the conductivity by the factor listed in the second column of table four. The factor depends on the conductivity units employed by your metre. If a natural water sample has an EC of 2.0 mS/cm, we can approximate that the TDS is 1,100 ppm (2.0 mS/cm x 550). *uncontaminated scheme water, bore water, swamp water Hard/Alkaline waters: These waters require a conductivity factor of around 650 (when measured in mS/cm). Inorganic nutrients: The typical grow and bloom hydroponic nutrient formulations have much higher concentrations of ions like potassium and phosphate. Consequently, these solutions require a much higher factor than the waters mentioned above (800 when measured in mS/cm). To further illustrate how important it is to consider the type of solution being tested, note that many high phosphate flowering additives will require a conductivity factor of 1,100 (when measured in mS/cm). 40

MAXIMUM YIELD Australia - March/April 2010

The problem with TDS in hydroponics It is not uncommon to find some hydroponic operators assigning a TDS value of about 1,400 ppm to the common 2.76 mS/ cm conductivity standard; they have used a conversion factor of 500, a factor which is only valid for relatively pure sodium chloride waters. As discussed above, 800 is a more realistic factor for hydroponics because many nutrient mixtures of around 2,200 ppm yield a conductivity of 2.76 mS/cm. Additionally, quoting TDS values derived from conductivity readings, and without quoting the factor used, can imply different conductivity values to different people depending on what conversion factor they favour! Consider the following scenario: You calibrate your TDS metre in a 2.76 mS/cm conductivity standard to 1,800 ppm. Using the same conductivity standard, your friend calibrates his metre to 1,400 ppm. If you then give your friend a nutrient strength recommendation he will add 30 per cent more nutrient than what you intended! To summarize, conductivity factors that attempt to accurately convert conductivity readings into TDS must be customized to suit both the concentration range and ratios of the particular salts present in the water being analysed. This requires prior knowledge of the sample’s composition, and logically, such an effort would be counterproductive. The inevitable conclusion is that the general use of conductivity to determine TDS is, at best, only an approximate method. Remember, the fundamental property being measured is conductivity. TDS is a derived value and employs guesswork of the composition of the solution. For these reasons, in the water industry it is fast becoming international practice to simply quote electrical conductivity (EC) values and not TDS. MY A handy and helpful table on recommended nutrient strengths for specific plants species can be found online at www.maximumyield.com

MAXIMUM YIELD Australia - March/April 2010

by Erik Biksa

Stability and Longevity The question on the table today is does CO2 go “stale” (for lack of a better term). Most substances, and molecules for that matter, are in a constant state of flux and are changing states, or the way they are formed on an atomic level. Arguably carbon may be one of the most stable molecules we have, and it’s a very important one. However, carbon dioxide is not just carbon, it is CO2 so there are two oxygen molecules attached, and oxygen can be relatively reactive. O2 as a compound offers a little more stability than something like O3, which is ozone. The extra oxygen molecule wants to leave the arrangement, as O2 is more stable. In most indoor growing situations, the CO2 in a tightly sealed growing atmosphere gets used up astonishingly quickly when plants are healthy and productive. The rate is also dependent on what stage the plants are at in the cropping cycle. This is why it makes good 42

sense to enrich the environment with a supplemental source of clean carbon dioxide if ventilation through outside air exchange is not constant during the lights on cycle. Ensuring that CO2 levels remain higher than ambient through various stages in the cropping cycle can increase yields by as much as 30 per cent and often reduce the overall amount of cropping time required, because plants produce at accelerated rates. In most situations, it seems that the most likely scenario is that the additional levels of CO2 will get used up faster than they may be able to degrade. However, it’s doubtful that any carbon dioxide enrichment system is 100 per cent efficient, meaning that other less desirable compounds may be introduced as gases when delivering Be careful with CO2 burners If used in an environment without a source of fresh air, harmful elevated carbon dioxide gases, such as ethylene and carbon, may be introduced when levels to crops. For example using gas-fired CO2 generators. trace amounts of ethylene

MAXIMUM YIELD Australia - March/April 2010

A HEPA filter can clean the air Passive, fresh air can be introduced to the grow set-up by using a HEPA intake filter. When combined with a fan that cycles air through the environment, the filter will help to remove any contaminants and provide a healthy growing atmosphere.

and carbon monoxide may be introduced using gas-fired CO2 generators. Since the plants do not want to use or absorb these gaseous compounds, they may build up to harmful levels in a tightly sealed growing environment; becoming toxic to plants. Also, for gas fired burners (CO2 generators) to work efficiently, they require a source of fresh air for the combustion process. Savvy operators of CEA (Controlled Environment Agriculture) or sealed grow set-ups allow for a slight “bleed” of the air to occur. For example, to ensure a very healthy growing atmosphere, a proportionately small, passive fresh air access is created and is “capped” off with a HEPA intake filter, as featured in some of my articles. With a carbon scrubber (activated carbon filter with fan) cycling constantly within the area, it will pull a small amount of fresh air into the grow room through the small passive HEPA intake. Excess air will “leak” out of the growing environment through any tiny cracks, etc. Remember it’s almost impossible to 100 per cent seal a room, so there are some cracks for the air to bleed out. The volume of fresh air being introduced is cleaned through the HEPA filter and does not introduce contaminants, just enough fresh air to help displace and dilute stale air or gases that can accumulate to toxic levels. Imagine a full glass of water that has a few drops added every minute; the volume of liquid will slowly be exchanged over time, keeping it fresh and palatable. MY Erik’s articles dating back 12+ years are available exclusively at maximumyield.com

MAXIMUM YIELD Australia - March/April 2010

Mobile Vegetable Garden by Michael Bloch

As I watched the hot, dry winds scream through the bush, sometimes accompanied by rather freaky dust devils that sounded like freight trains approaching, I started to think that maybe I’d never be able to establish a vegetable garden on my patch of dirt.

There’s not many veggies that can withstand heat of up to 48°C and a week straight of 40°C+ temperatures without a lot of intervention. Even the drought resistant Galapagos tomato seeds that await my action I suspect won’t be able to stand the combination of heat, wind and lack of rain that seems to be the norm during Australian summer months. Until now we’ve had less than two millimetres of rain for the year. It’s not so much any particular element, but the combination and extremes we are experiencing that pose the biggest challenge for home veggie growers in Oz. Installing a rainwater tank or rain barrel to keep vegetable gardens going is a great idea as is mulching, but that only addresses a few issues. After looking a little into square foot gardening recently, it dawned on me that an extension of that is likely the way to go—mobile square foot vegetable gardening. Back in my late teens, I used to work in a plant nursery with azaleas. We had huge barrows that we used to fill with potted plants to move them between potting areas. Even though the fully ladened barrows weighed a great

MAXIMUM YIELD Australia - March/April 2010

deal, they were easy to manoeuvre and very robust. I think that a variation on these barrows may be ideal for growing vegetables, with the added benefit of being fully mobile. A nursery barrow could be quite easily converted to a mobile vegetable garden with the right trough insert. By replacing the wire carrier frame with a sturdy recycled food grade plastic trough of suitable height, this set-up could work quite well and applying the principles of square foot gardening, may only take a few barrows to service a family. Actually, the wire frame could remain in order to give the barrow extended applications. Freezing in winter? Move the barrow to an area of your yard thatâ&#x20AC;&#x2122;s not so prone to frost, or into a garage for the night. Too hot and dry in summer? Move the barrow to a shady spot for the afternoon. Too windy? Shift it to a sheltered area until the wind abates. Too wet? Again, move to a sheltered area during the deluge. Additionally, the system would use far less water and be much easier on the back and knees when it comes to working the garden. Accessories could include a drip irrigation system fed by a bolt-on water feeder tank, frames for climbers such as peas and beans, framework and covering to create a mini-greenhouse, inserts for growing potatoesâ&#x20AC;&#x201D;the possibilities are endless. With a little ingenuity and creativity, you can have a garden that thrives, no matter what challenges you face as a grower. MY

Michael Bloch is the owner and 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. MAXIMUM YIELD Australia - March/April 2010

Seaweed A Precious Material for Plant Nutrition

by Luis Bartolo

Seaweed has been harvested for food, fertilizer and medicine for thousands of years. History books record that the Chinese used seaweed for medicinal purposes as early as 3000 B.C. The Greeks used seaweed as animal food as early as the first century B.C. One translated text written in 46 B.C states: â&#x20AC;&#x153;The Greeks collected seaweed from the shore and having washed it in fresh water, gave it to their cattle.â&#x20AC;? Today China and Japan are the biggest consumers of seaweed worldwide, with China harvesting 500 million tons a year for food use alone. Seaweed has also been as a source of organic material to add to soil or soilless cultivation. It is only during the latter half of the last century that techniques were developed to fully understand the physiological responses that seaweed clearly produces. Techniques were developed to extract and concentrate active ingredients used to influence the plant physiology. The use of seaweed in agriculture has moved from using a simple dried product, which was harvested by hand and spread on the soil, to distribution of so called seaweed derived products manufactured into small dried flakes, suspensions or solutions containing active ingredients produced from the seaweed raw material.

MAXIMUM YIELD Australia - March/April 2010

What is seaweed? In the classification of all living things, seaweed is within the ‘plant’ group, although it is a little behind in evolutionary terms compared with the more familiar plants seen every day. Seaweed may belong to one of several groups of multi-cellular algae: the red algae, green algae and brown algae. As these three groups are not thought to have a common multi-cellular ancestor, the seaweeds are a paraphyletic group. In addition, some tuft-forming blue green algae (Cyan bacteria) are sometimes considered as seaweeds. “Seaweed” is a colloquial term and lacks a formal definition. Botanists refer to these broad groups as Phaeophyceae, Rhodophyceae and Chlorophyceae, respectively. Brown seaweeds are usually large, and range from the giant kelp that is often 20 metres long, to thick, leather-like seaweeds from two to four metres long, to smaller species 23 to 58 centimetres long. Red seaweeds are usually smaller, generally ranging from a few centimetres to about a metre in length; however, red seaweeds are not always red. They are sometimes purple, even brownish red, but they are still classified by botanists as Rhodophyceae because of other characteristics. Green seaweeds are also small, with a similar size range to the red seaweeds. Seaweed contains all known trace elements. These are present in a form that is acceptable and available to plants. Trace elements can be made available to plants by chelating—that is, by combining the mineral atom with organic molecules. Effect of seaweed Research shows that high quality seaweed extracts can have a five-principle effect on plant growth. All of them remove or reduce the influence of a number of growth constraints, with the result that treated plants function better, and produce higher yields and better quality crops. Seaweed supplies all trace elements required for plant growth across the entire spectrum. Seaweed and seaweed products also exert some form of biological control over a number of common plant diseases such as pythium. Soil fungi and bacteria are known to produce natural antibiotics, which hold down the population of plant pathogens, and when these antibiotics are produced in sufficient quantities, they enter the plant and help it resist disease. The production of such antibiotics is increased in soil high in organic matter, and it may be that seaweed further encourages this process. Seaweed also acts as a soil conditioner. It has the ability to transform light

MAXIMUM YIELD Australia - March/April 2010

Seaweed: A Precious Material for Plant Nutrition

"Applied to plants that can cold acclimatize, seaweed extract initiates or speeds up the acclimatization process even when the plant is not subjected to a cold stress." and sandy soils into denser mediums by creating organic polymars, which bind the soil particles together. This creates better structure and also assists in water retention. Immune system A regular application to the foliage of plants induces Localised Acquired Resistance (LAR) against a range of fungi, bacteria and viruses. There are indications that this effect may also be systemic. Applications also improve the plant’s ability to withstand certain levels of environmental stresses and reduce the attacks and flare-ups of sap-sucking insect pests on the plants. As well as resistance to frost through this method, a localised resistance to heat stress can also be utilized by the plant through the application of seaweed. The plant’s cells respond to the seaweed’s nature of existing in deep cold, helping the plant to cool down. Chlorophyll Foliar application of seaweed extracts will result in greater maintenance of chlorophyll, leading to greener plants. This is in part due to a complex family of different betaines in the seaweed extract, which help reduce natural damage to the photosynthetic process. Research has shown that application through foliar sprays and watered into the growing medium has the same effect on enhanced chlorophyll, and in most cases produced actual higher levels of chlorophyll in the plants. Microbes Specific carbohydrates in seaweed extracts serve as a source of food for beneficial and benign soil bacteria, resulting in a large increase in microbe numbers. These microbes produce plant growth stimulating compounds that encourage root growth and a significantly larger root mass. The increased bacterial population can also both physically exclude and compete with potential plant pathogenic soil fungi. Research has proven that seaweed contains qualities that make plants more resistant to insect and fungal disease. The activation of the natural microbial

structure of the soil or medium in combination with all trace elements makes the plant stronger and better able to deal with attacks. The carbohydrates in seaweed and seaweed products work in natural combination with the iron, cobalt, copper, manganese, zinc and other trace elements. That is why these trace elements in seaweed and seaweed products do not settle out, even in alkaline soils, but remain available to plants that need them at all times. Nematodes The complex range of compounds found within seaweed extracts can help reduce nematode damage. This includes a reduction in hatch and a disorientation or simple ‘burn-out’ of immature nematodes (J2s), minimizing root penetration. Frost Applied to plants that can cold acclimatize, seaweed extract initiates or speeds up the acclimatization process even when the plant is not subjected to a cold stress. This allows plants to tolerate greater levels of cold, reducing the amount of damage. As you can see seaweed is one of the unique organic compounds that can be used in agriculture in many different ways. Beside the immune system the usage of seaweed has a lot of benefits: • beneficial for the environment • does not harm birds or any other animals • increases root depth and branching • fortifies the plant’s natural defences • increases plant’s nutrient absorption capacities • improves colour/quality of vegetables, ornamentals or lawn • breaks down large organic molecules into easier to absorb MY subunits Learn more about natural nutritional alternatives including seaweed at www.maximumyield.com under our article archive.

MAXIMUM YIELD Australia - March/April 2010

CHECK YOUR growing I.Q.

by Erik Biksa

1. Which of the elements in the list below is commonly mistaken to be deficient in supply, when typically the causal agent of the symptoms is more often related to pH? a) calcium b) magnesium c) nitrogen d) potassium

4. Why do both coco coir and rockwool medias require special considerations with regards to pH, noting that the greatest consideration is with rockwool?

2. What is considered to be the optimal pH range for absorption of this element in hydroponic (water culture, excluding rockwool) systems (while considering the availability of all nutrients)? 3. What is considered to be the optimal pH range for absorption of this element in soilless (water culture, excluding pure coco coir) medias (while considering the availability of all nutrients)?

5. Scientists rate surfactants according to the HLB of their molecular structure. What does HLB stand for? a) hydrophillic lipophillic balance b) hot looking babe c) holding lipidic balance d) none of the above 6. If the HLB scale is between one and 20, in most horticultural applications it is best for surfactants to be in the _______ portion of the HLB range. a) low b) mid c) high

ANSWERS: January/February 2010 quiz

1) c 2) a 3) because ppm is a conversion from EC. Different manufacturers use different conversion rates, making it far less of a universal measurement. 4) a 5) d 6) a Answers to this quiz will be printed in the May/June 2010 issue of Maximum Yield.

MAXIMUM YIELD Australia - March/April 2010

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