Undercover
farming
ucf
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January - february 2019 Volume 16 No 1
I I R40.00
CUCUMBERS
produce
PEST MANAGEMENT
FOOD SECURITY
Family Farm Produces Quality Cucumbers Page 4
Magnesium deficiency in tomatoes Page 18
Foliar sprays in perspective Page 20
Food traceability and risk management Page 16
Undercover Farming Conference 6-7 March Program inside (Pp12-13)
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MAIN ARTICLE
PROPRIETOR I ADVERTISING SUZANNE OOSTHUIZEN 012-543 0880 I 082 832 1604 suzanne@axxess.co.za EDITORIAL CONTENT & COMPILATION Johan Swiegers 082 882 7023 editors@axxess.co.za ADDRESS PO Box 759, Montana Park 0159 E-MAIL magazine@axxess.co.za FAX 086 518 3430 ADDRESS PO Box 759, Montana Park 0159 DESIGN Fréda Prinsloo PRINTING Business Print Centre DISCLAIMER Undercover Farming accepts no responsibility for claims made in advertisements or for opinions and recommendations expressed by individuals or any other body or organisation in articles published in Undercover Farming. COPYRIGHT Copyright is reserved and the content may only be reproduced with the consent of the Editor. Subscription Online subs: Email to suzanne@axxess.co.za If you subscribe on-line, e-mail your deposit and address details to: magazine@axxess.co.za. More information from Suzannne Oosthuizen: 012-543 0880. Subscription form available on inside back page. visit us at I besoek ons by
from the SCRIPTUREs
Luke 9:62 Jesus said to him, “No one who puts his hand to the plough and looks back is fit for the Kingdom of God.”
Contents 4
Family farming is still going strong: the story of a cucumber producer
7 Advanced technology applied to grow herb seedlings 8 Tomato producers warned about ToBRFV 10 Foliar sprays in perspective 12 Official Programme Undercover Farming Expo 2019 14 The confusion clarified: Phosphoric acid vs
FRONT PAGE: Louise Buitendag of Jenlu Farms in a cucumber production house.
INSIDE ...
Phosphorous acid
16 Food traceability and risk management before the farm gate
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17 About magnesium deficiency in tomatoes 18 Cannabis in the workplace – how it could affect the farmer and his workers
19 Sanitation in the greenhouse – how this can save you money
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20 Grow media play important part in disease management
22 Marketing strategies for a greenhouse operator 23 Quality and quantity assurance with rootstocks
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ifferent times and even difficult times, brings different solutions. If somebody never said that, maybe one day I will be quoted as having talked sense. As one discusses the current situation and particularly that of greenhouse and shade net farming some similar facts are stated by role players around the country; business is slow, the small producer that never re-invested in upgrading his system was forced financially to leave the trade, the current political and economic situation and lack of interest by government to relax certain regulations to favour agriculture, to name a few. But on the flip-side of the coin, the very same people talk about overcoming obstacles like these in ingenious ways! Farming is about waking up every morning with a fresh mind about your business. As said before in this space, the greens industry has so much going forward it only needs to be managed correctly. Investors are currently scarce, but laying a well drafted plan of success before them shall make them sit up straight. South African based greenhouse companies are doing business up in Africa, and why? The respective countries’ governments are promoting agriculture and exporting their produce to Europe and elsewhere. Why did Kenya and the rest of them take our flourishing (at a time) flower business from us? Let us be positive about getting food production minded people into greenhouse farming – it is the way to go forward in this country. So many technologies make life so much easier for a greenhouse farmer as long as he has a steady demand for his produce. Elias Hasket Derby said; “Agriculture has become essential to life; the forest, the lake, and the ocean cannot sustain the increasing family of man; population declines with a declining cultivation, and nations have ceased to be with the extinction of their agriculture.” In the long term, this is fact. The Undercover Farming Conference 2019 speakers should renew interest in greenhouse farming and many newcomer delegates will leave afterwards with positive ideas of running their operations and so increase the greenhouse sector in South Africa!
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Louise Buitendag and daughter Chanel Myburgh (micro-biologist) with her husband Eric on Bultfontein farm and Jan Koekemoer (Farm Manager).
Family farming is still going strong: the story of a cucumber producer
With so many opportunities luring the youth to cities after they finalised their studies, the historic handing down of farms to the next generation is fast disappearing. It is therefore an interesting occasion to visit a farm and sit around a table with the family who started a production unit and have their family members employed with the view of eventually have them carry on.
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his is the case when Undercover Farming visited the Buitendag family who purchased their farm and started off in 1995 at Buffelsfontein near Rustenburg. The farms are now better known as Jenlu. Having become successful in greenhouse cucumber production, they purchased two additional farms in 2016 in close proximity to each other.
Unfortunately the infrastructure, home, and shed structures were in a rather derelict condition but Jan Buitendag and his wife Louise with the family joining hands and the least capital these were soon restored. Greenhouses were selfconstructed and covered according to advice gained from experienced suppliers. Jan and Louise Buitendag trust that with Faith, strength and belief, anything is achievable. Therefore every morning is started with reading from the Bible and praying with all the employees to ensure a fruitful and thankful day on the farm. Jan Buitendag and his wife Louise lives on the “Mother Farm”, daughter Chanel Myburgh (a micro-biologist) with her husband Eric on Bultfontein farm and
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son Derik on Hartebeestfontein farm. On the “Mother Farm” there is a good unified management structure whereby Karen van Wyk the (Bookkeeper) and Jan Koekemoer (Farm Manager) help with the success of the farm. The “Mother Farm” and the 2 other farms bringing the total Greenhouse production to just under 7 ha. Packing is done on the “Mother” farm as well as the farms in Hekpoort using state of the art wrapping and cooling facilities. Cucumbers from Rijk Zwaan seed are produced on all three farms. They grow their own seedlings from different winter and summer varieties of Rijk Zwaan seeds and interestingly, grow the seedlings in the houses where the plants will actually produce so as not to disturb their environment and have a quicker response and less loss of seedling cost. According to Louise they also obtain new cucumber seed varieties from Rijk Zwaan and perform trials in their greenhouses.
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Cucumbers from Rijk Zwaan seed are produced on all three farms.
This resulted in Rijk Zwaan company members from the Netherlands visiting the farms to observe the results. The Managing Director of Rijk Zwaan Gerhard Smit visits the farm regularly. Jenlu Farm believes in doing things simple and straight forward, saving on expenses but proving that good management results in good quality produce and a fair living for all family members. The water on the farms are of excellent quality and is regularly tested every three weeks against any form of water-borne pathogens and samples taken for an approved laboratory as they are running the business under GlobalGap(Intermediate) regulations which they received 100% over the last 4 years. This is where Chanel and Eric come in handy. They also inspect plants for any possible disease and sees to it that plants are being treated against diseases promptly. This is part of good greenhouse sanitation and management in general as it further save the farms from losses. The cucumber plants are grown in pine sawdust in black plastic bags with drip irrigation. Personal attention in the houses while staff is working is a daily routine. Louise does not believe in thinning out during production season and allow plants
to produce optimally with the best care possible. They use FM Agri Care to advise them on all applications to their plants’ wellbeing. Watermelon mosaic virus caused problems at the beginning due to the existence of the virus on the farm before it was bought by Jan and Louise Buitendag. However, by applying the Integrated Pest Management (IPM) system they were able to remove all signs of the virus by means of Cultural and Chemical management. “When the climate is in our favour and all things constant, we harvest up to 30 cucumbers off a plant but generally we try to average 25 in season. Cloudy, overcast and rainy days have us drop in production but then, when the sun breaks through we increase production and thus keep the farm on an even keel,” Louise explained, being Managing Director of the business. Jenlu Farm has a program according to which they alternate harvesting on the farms during the week. Harvesting takes place throughout the week excluding Wednesday. On Mondays and Thursdays, harvesting takes plays on the “Mother” farm and on Tuesdays and Fridays on the Hekpoort farms. During harvesting the packing process runs simultaneously
to ensure fresh produce. An average of 120 000 cucumbers are produced weekly. Louise found a recipe to make cucumber chutney and sold quite a bit with great success – another way of optimising her second-grade fruit on the farm whilst earning an income. A manufacturing and marketing plan is in progress. Jenlu Farm is truly a family concern of note. Each member knows exactly what his or her daily program is and meetings are held at appropriate times for all. There new ideas are discussed or any hiccups sorted out in a family way but also in a business-like manner. Cooperation of this kind leads to a business that will be handed down in generations to come – something which we are sadly losing out in South Africa. A family concern is easier to run and crisis simpler to solve. The youth brings new technology which mostly saves the business money and therefore they are always welcome to air their views or test their ideas against current production activities. “We work hard as a family in a businesslike manner during the week, but spend our week-ends together without talking about business to keep family ties strong,” concluded Louise Buitendag.
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Advanced technology
applied to grow herb seedlings According to Doron Naveh, Afula Nursery Manager, and Eyal Kleinberger, Herbs & Perennials Product Manager at Hishtil, culinary experts worldwide have already become accustomed to using fresh herbs, and in recent years even foodies grow herbs for personal use, on every windowsill and balcony, in planters or in the garden.
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ccording to Doron Naveh, Afula Nursery Manager, and Eyal Kleinberger, Herbs & Perennials Product Manager at Hishtil, culinary experts worldwide have already become accustomed to using fresh herbs, and in recent years even foodies grow herbs for personal use, on every windowsill and balcony, in planters or in the garden. Hishtil is a major party in this trend, one of the world’s largest herb plant producers, which specializes primarily in producing plugs and unrooted cuttings that are marketed to nurseries worldwide. The nurseries care for the plugs in planters, and sell them to retail chains as half-finished plants, mainly throughout Europe and the North America. According to Doron Naveh, Afula nursery is responsible for producing the herb plant plugs: “We grow any plant that can be propagated vegetatively – mint, rosemary, oregano, thyme, sage, basil, and others in hundreds of varieties, different flavors or appearance. Multiple plugs provide an advantage in uniformity of the final product, in terms of appearance and variation. Hishtil Afula (one out of 4 Hishtil nurseries in Israel) is in charge of the vegetative production, 95% of the plugs produced for export, 5% intended
for the local market. Sales of Herbs take place to most countries like England, Holland, Germany, Belgium, Scandinavian Countries ,France, U.S.A, Canada, Switzerland, Italy, Poland, Hungary, Austria, Cyprus, Russia, Slovenia, and even South Korea and Japan. The produce reaches markets directly from production site at Afula nursery via air freight within 72 hours after packing! Production scale increase requires Hishtil to continue investing many resources in technological means for improving efficiency, optimizing and upgrading of production processes, for the sake of product quality and employees well-being during production. Hishtil recently invested in an upgrading of its ‘sticking’ room at the Afula nursery, where the employees stick cuttings into various plug sizes. Doron related that in this upgrading process, 3 objectives were defined: to enlarge the
room’s area to provide greater working space, to make the work process more efficient, and to improve sanitary conditions for improving the plugs quality. As a result of the new facility, Hishtil managed to improve sticking procedure without the need of additional manpower, while making the working process more efficient and a
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Tomato producers warned about ToBRFV Tomato brown rugose (ToBRFV) fruit virus is found in several countries where horticultural practice takes place. It is a relatively new virus and is related closely to TMV and ToMV, according to Belgium experts of Proefcentrum Hoogstraten.
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t is generally accepted that almost all current available tomato varieties are resistant to both TMV and TOMV, but this new virus broke the resistance barrier. The symptoms of ToBRFV are similar to the PepMV. ToBRFV can spread out easily within a greenhouse since it can spread out via hardware being used in the greenhouse. Spreading from one greenhouse to another can occur via visitors or seasonal workers, exchanging material but also birds or bumblebees, or even a united packing shed. ToBRFV may not necessarily be transmitted via seed, but there’s no guarantee on this claim. According to horticultural scientists, Tobamovirusses in general are very persistent and can survive for a long time without a host plant and on inert materials like clothes or tools, in plant rests, soils or anything without losing their virulence. Therefore a thorough disinfection during crop rotation is advised as well as
hygiene rules during the crop. Italian professor Walter Davino shared the discovery of the virus in Sicilian greenhouses. He remarked; “It is a very dangerous virus because it
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can be transmitted in multiple ways. It is most important to be careful about the contact between each plant and the operator working in the greenhouse. There are pieces of evidence 9
Tomato producers
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detected in 8 nurseries growing tomatoes showing that it can be transmitted (Solanum lycopersicum) and capsicum through the seed, as well.” (Capsicum sp.) in the municipality of On November 2, 2018 the CDFA Yurecuaro (State of identified the Michoacan), Mexico. ToBRFV infects tomato associated pathogen The symptoms found as Tomato brown plants and leads to mosaic on fruits included rugose fruit staining of the leaves as yellow discolouration, virus. On further well as discolouration and green spots and investigation of deformations of the fruits. deformations, green the situation in grooves and irregular California, CDFA brown spots, and on leaves; mosaic was notified by the company that all symptoms, spots and yellowing. ToBRFV-infested and symptomatic plant material had been voluntarily destroyed, First discovery thereby preventing the collection of The earliest discovery of ToBRFV was an official sample. However, the risk in Jordan in 2015, but then found to associated with possible introduction of have already occurred in Israel in 2014. ToBRFV and a suggested rating for this ToBRFV infects tomato plants and leads pathogen is documented on the CDFA to mosaic staining of the leaves as well website. as discolouration and deformations of the fruits. In September 2018, ToBRFV was first
Foliar symptoms included chlorosis, mosaic with dark green bulges and narrowing Fruit symptoms consisted of yellow spots, often concentrated around the calyx with occasional rugose symptoms rendering the fruits nonmarketable. The new isolate sequence (TBRFV-Mx, MK319944) shows a 99.8 and 99.9 % nucleotide homology with Jordan and Israel isolates, respectively.
against pests, fertilizer additives, and more. All these actions, that were not possible in the previous arrangement, can be implemented uniformly in the future in the new facility. In recent years Hishtil has joined the worldwide trend of organic food, and was the first to bring this tiding to the herb plants market as well. As of today, Hishtil has a wide selection of organic herb plants, of the highest variety and quality available in the market.
variety of shapes, colours and flavours. In addition, combinations of various herb varieties will be exhibited, varieties with an Asian fragrance, combinations of herbs for tea, as well as an innovative concept of plants with high resistance to dryness – that are suitable for climate changes in recent years.
Advanced technology
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higher product quality. In the upcoming year we have plans to implement a recognition system in order to improve our monitoring abilities throughout the production chain. As noted, the system is built and planned for continuous processing and improving logistics and efficiency at work. The upgrading process has also enabled technological improvements meant to realize a more professional outcome. For example, by installing new climate control device, Hishtil managed to gain better pest control which resulting better and plugs in a higher sanitation conditions. According to Eyal Kleinberger, the upgrading production process also making efforts to forecast the future. It is meant to provide the means to permit application of additional materials in the sticking process. For example, treatment
South Africa, being a major tomato growing country in the south of Africa, may not be excluded of ToBRFV and growers, especially greenhouse operators are urgently warned to increase their awareness of greenhouse hygiene and that of staff and the tools they use in their daily work in greenhouses and packing sheds. (Excerpts from information by A. Sijmonsma)
Hishtil hasn’t stopped innovating, participate in two central tradeshows in the horticulture and vegetables sector (IPM & Fruit Logistica, Respectively), where it exhibits new products: a series of cascading herbs varieties, highstem products – basil and edible pepper, and a series of grafted hot peppers (Janana-Peppers that BITE), in a
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Foliar sprays in perspective
It is now known that not only nutrients can be foliar absorbed but also pesticides, growth regulators, organic acids and many carbohydrates.
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he main advantage of using foliar applied fertilizers is that they can be rapidly and effectively absorbed, ensuring a quick plant response. Because they are so effective they require less fertilizer input and bypass soil fixation and leaching. Another advantage is the fact that they are effective when plants have a have a restricted root system, periods of environmental stress, seasonal root loss, periods of low photosynthetic output and a correspond low carbohydrate reserve. Foliar applications of nutrients as a supplementary fertilizer are highly effective.
FACTORS AFFECTING FOLIAR ABSORPTION Several factors which will affect foliar absorption include relative humidity, temperature, pH of the nutrient solution, variety, age of the leaf, concentration of the nutrient solution, difference in the nutrient compounds (formulations) use of surfactants and the addition of non-nutrient facilitating or carrier-mediated agents. Humidity and temperature has a direct relationship with absorption of nutrients and as they increase, penetration also increases. The total amount of time the nutrient is in contact with the leaf is critical. Optimum pH is a factor that varies from nutrient to nutrient and most good manufacturers / formulators recognize the need to have optimum pH for the nutrient used. Many chemical compounds are ineffective as foliar nutrients and thus only tried and tested products should only be used.
MODERN FOLIARS The efficacy of modern foliar fertilizers varies significantly and is directly proportional to the quality of the product. Using both organic and inorganic facilitating agents to transport the cations into and throughout the plants has become a very exact science. Many humic and organic materials (notably amino acids) have the capacity to bind substantial amounts of metals and other cations, and they can therefore exert considerable control over the supply and availability of nutrient elements to plants. When the metal ion combines with an electron donor, the resulting substance is said to be a complex. If the donor atoms are attached not only to the metal ion but also to each other as well forming a ring, it creates a chelate. The Metalosate™ range is a true amino-chelate with an overall zero net charge and is fully available to the plant.
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Synthetic chelating agents have been used as aids in plant nutrition for many years. Among the more popular ones are EDTA, HEDTA and others. They are cost effective and can be effective if used properly but they are often not biodegradable. Synthetic chelating agents are intended for use mainly in soil to prevent the attached nutrients from forming a bond with the soil colloids and thus remain more available for root uptake. In general however they do not work well as a foliar fertilizer agent, but rather for soil application. The best chelating agents are those that are natural components found in the metabolism of the plant, such as carbon and amino acids. Humidity and When apply foliar temperature has a fertilizer sprays direct relationship with containing the correct absorption of nutrients form of nutrients, and as they increase, this eliminates the penetration also increases. limiting element and influences plant metabolism and photosynthesis. With enhanced photosynthesis the plant begins to produce more carbohydrates and in the process requires more water. The stomata on the leaf open allowing water vapour to escape, which reduces the water pressure in the xylem tissue allows more water to flow up the vascular bundle. In turn more water is absorbed into the roots to replace the water moving up. If good nutrition is available in the soil surrounding the root, extra nutrients enter the plant with the water. If you visualize the plant as a water pump, the foliar fertilizer acts as a primer, priming the pump and bringing more nutrition into the plant. It is important to remember that the foliar fertilizer actually increases the total uptake of nutrients by several folds over the small amount of foliar fertilizer applied. Some fertilizer compounds penetrate the waxy cuticle of the leaves with difficulty. In many cases this is due to rapid crystallization of the fertilizer on the leaf surface impeding its subsequent movement through the cuticle. Liquid carbon sources (and amino acids) are a breakthrough in foliar sprays as it facilitates direct absorption through cell membranes. By: Mike Haupt
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Undercover Farming CTICC International Convention Centre, Pretoria
Wednesday 06 March 2019 07:00 – 09:30
Registration: ALL DELGATES & EXHIBITORS – Network on Expo Floor
09:30
Welcome: Suzanne Oosthuizen, MD: Undercover Farming Expo
09:30 – 10:00
Keynote Address: The Gauteng Department of Agriculture and Rural Development
10:00 – 10:45
Topic: Presented by Kleinskuur Farm – Colin Bremner “Aquaponics – The sum of aquaculture and hydroponics – Building blocks of a business”
10:45 – 11:30
Topic: Presented by Agri-Alchemi – Lindi Grobler “Calcium - the problematic nutrient ”
11:30 – 12:15
Topic: Presented by Green Terrace – CEO: Mbali Nwoko “From city girl to farmer – the Mbali Nwoko journey”
12:15 – 13:30
LUNCH - (Registered Delegates & Exhibitors) – Served in Foyer at entrance of Conference/Expo Hall
13:30 – 14:15
Topic: Presented by Green Meds – Gail Pedra “Cannabis Farming in South Africa & Africa”
14:15 – 15:00
Topic: Presented by APAC – Francois Knowles “Regulation in turbulent times”
15:00 – 15:45
Topic: Presented by Pratley South Africa – Eldon Kruger “Perlite as growing medium”
15:45 – 16:30
Topic: Presented by Delphy South Africa – Herbert Stolker “Re-use of run-off water in the greenhouse/tunnel industry”
16:30 – 18:00
Networking Session – FREE ENTRANCE (Delegates, Public & VIP Guests)
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Expo ’19 Thursday 07 March 2019 08:00 – 10:00
Registration / Networking session with Exhibitors (Tea & Refreshments will be served)
10:00 – 10:45
Topic: Presented by Cherry Irrigation - Charles Cherry “Irrigation principles in greenhouse production”
10:45 – 11:30
Topic: Presented by PlusNet – Deon Snyman “Overview of Shade Netting and Shade Net Cover Construction”
11:30 – 12:15
Topic: Presented by Talborne Organics – Jenny Slabber “Healthy, safe and sustainable organic options for the horticulture industry”
12:15 – 13:30
LUNCH & Networking on Expo Floor
13:30 – 14:15
Topic: Presented by AgriLED – Theo Pistorius “Undercover Farming: A disaster-relief and community rebuilding tool”
14:15 – 15:00
Topic: Presented by Mike Loutfie Foundation – Kholisa Ngalo “Access to Fresh Produce Markets”
15:00 – 17:00
Networking Session / FREE ENTRANCE (Delegates, Public & VIP Guests)
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The confusion clarified:
Phosphoric acid vs Phosphorous acid
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veryone growing a plant will acid with phosphorous know phosphorous (P) is one acid. Phosphoric acid and of the essential plant nutrients phosphorous acid is not the that a plant needs in various same compound and they do concentrations (depending on the plant not have the same function being grown) for normal growth and in a plant! development. The principle function of Phosphorous acid is phosphorous is that of energy transfer in often referred to as the plant. It forms nucleic acids to assist, phosphonate, phospohonic in combination with other nutrients, with acid or phosphite (salt photosynthesis, respiration, cell division of phosphorous acid). and elongation. When phosphorous acid Phosphorous uptake is often temperature disassociate, phosphorous dependent and a deficiency of the acid releases a phosphite ion. element results in retarded growth and Like phosphate, phosphite negatively influences shoot and root is easily taken up and growth as well as mass. It also depresses translocated inside the plant fruit and seed but is available Many growers often formation with in the plant as confuse phosphoric acid an overall poor phosphite. quality fruit The phosphite with phosphorous acid. development. anion in the Phosphoric acid and Phosphate is the plant solution phosphorous acid is not interferes with primary source the same compound and certain fungus’s of phosphorous they do not have the metabolisms for the plant. In same function in a plant! and when fertigation systems this process of fungistasis phosphorous occurs, the particular fungus cannot is given in the form of either MAP produce enough energy and it dies. Technical (mono ammonium phosphate) and/or MKP (mono potassium While phosphoric acid thus produce phosphate), but there is one other phosphate as a plant essential nutrient, source of phosphorous; phosphoric acid (H3PO4 ). Phosphoric acid, however, is primarily prescribed when highly buffered water sources are used in fertigation (high bicarbonate or carbonate containing water). Based on a water sample analysis the application of phosphoric acid not only buffers water allowing fertilizer raw materials to establish pH in solution, but it also supplies phosphate (through the dissociation and release of hydrogen phosphate and dihydrogen phosphate) nutrition to the plant. Many growers often confuse phosphoric
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phosphorous acid produces a phosphite anion in a plant as a systemic fungicide in the control of Oomycete family of fungi, including Phytophthora, Pythium and Plasmopara. The one cannot be substituted for the other‌
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Food traceability and risk management before the farm gate
Traceability of food is a leading global news topic. Periodically there is a new crisis such as needles in strawberries, E. coli in leafy greens and Listeria in melons. Almost daily we read about traceability projects based on blockchain, and less frequently about the existing GS1 system of standards and barcoding.
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mphasis is placed on tracking food from farm to market, so a problem can be traced back quickly to the source farm. But is that focus in the right place? As soon as a product safety problem or risk is detected, the whole product line is often withdrawn from retail shelves and the supply chain is put on hold until the source is found and removed. The better the traceability to the farm gate, the faster the risk can be resolved and safe supply restored. Besides the harm caused to consumers, there is great economic harm across the supply chain. An affected business probably won’t recover from a product safety event that caused serious illness or deaths. An entire industry, commodity or brand can experience reputational damage by being mistakenly implicated as a whole. The overall supply chain suffers losses as trade activity is limited and consumers change brands or supply sources. Traceability back to the farm gate is only part of the story. We should be equally or more interested in systems to prevent the problem in the first place, and to find its actual source on or before the farm. A key strategy for mitigating risk on farms is industrybased assurance schemes, in which the leading grocery retailers place food safety system requirements on their suppliers. These producers and packers have to be trained, have suitable facilities, assess their risk vulnerabilities and manage them to industry standards. They must become accredited, certify all produce, keep records to demonstrate compliance, then maintain their accreditation under periodic and often unannounced audit. In Australia, several industry schemes are being harmonised under the HARPS banner. Most consumers would be astonished at the effort required of producers and packers of supermarket foods, especially fresh produce and meats. Businesses need
Traceability back to the farm gate is only part of the story. We should be equally or more interested in systems to prevent the problem in the first place, and to find its actual source on or before the farm. to be highly organised and the cost of compliance is high. Data is a key farm cost component, in monitoring, recordkeeping, certification and audit. Businesses gain large efficiencies from an electronic system in which data is captured on smart devices and uploaded to a cloud platform that is auditable. Data integrity is enhanced if the devices capture the location, time, date and person associated with the activity record. This on-farm data is transformed into usable information that can be linked to supply chain traceability systems beyond the farm gate. Mobile data systems, such as provided by AgKonect, can capture and manage all the data and information requirements for food safety assurance schemes. Additionally, a producer can customise their system to manage operations and capture data for any other process in the production chain, going right back to a farm block or tree. Data can be linked to a lot or batch number assigned to a production run. The lot or batch can then be linked to a product global trade item number (or
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GTIN) which is encoded into a product barcode. Some products such as leafy greens may be bundled onto a returnable tray, with a global returnable asset identifier (GRAI) encoded into the barcode label. A scan of the barcode label on the tray at a retail store informs the retailer which producer the number in the barcode label was assigned to. This is the essence of the GS1 system of standards and is the basis for traceability and trace-back. Provenance and product integrity information can even be provided through a web portal linked on the label. Farmers know the importance of quality and consumer protection. An on-farm data system can provide usable information to whole-of-supplychain traceability systems. The farmer manages their own food safety business risks, achieving new management efficiencies and opportunities, while adding value to supply chain traceability. By: Peter Whittle, CEO and Co-founder at AgKonect andBiosecurity Systems
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About magnesium deficiency in tomatoes Magnesium is the central constituent of the chlorophyll molecule – the green pigment necessary for photosynthesis. Plants do not need a lot of magnesium and it is relatively mobile in the tomato plant, meaning that it can move independently within the plant.
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agnesium deficiency is a common nutritional disorder in tomatoes. A mild deficiency has little effect on fruiting but a severe deficiency may cause smaller fruit and yield loss. The symptoms generally appear first on the middle leaves when plants are carrying a heavy fruit load. The middle and bottom leaves begin yellowing between the veins, which remain green (intervenal chlorosis). The deficiency can progress rapidly from older to younger leaves. The older leaves can become entirely yellow or orange, and brown spots may develop between the veins. Shoot growth, leaf size and fruit production are not usually reduced unless the deficiency is very severe.
Causes: Several factors influence magnesium deficiency 1. The season: Deficiencies are more common in autumn and winter when soil temperatures are low (<17°C). 2. Fruit load: Just before the first harvest, when the fruit load on the plants is at a maximum, root growth stops and older roots can die off. This hinders magnesium absorption. 3. Poor soil structure and drainage, which inhibit root development. 4. Low levels of magnesium in the irrigation water.
5. Excess calcium and/or potassium in the soil. 6. High EC (electrical conductivity) levels in the soil, caused by high-potassium feed. 7. The variety of tomato: Some varieties may be more sensitive than others, especially when there is a heavy fruit load.
Advice 1. The total magnesium level in the irrigation water should be 40–70 ppm. Calcium levels should be maintained at 80–150 ppm. Potassium levels in the irrigation water should be between 150 and 300 ppm, depending on the stage of the crop. 2. Foliar spray: Magnesium can be supplied by foliar spray, using 2% magnesium nitrate (Magnisal). However, there is a risk of burning the leaves, especially in hot weather. 3. Maintain reasonable EC levels in the soil. 4. Ensure that the soil has good drainage and that roots can develop properly. To ensure your tomato crop retains its splendour and quality for the market, it is advisable to take note of the above advice and train greenhouse attendants accordingly. By: Howard Wener
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Cannabis in the workplace – how it could affect
the farmer and his workers
Since the legalisation of the possession and use of cannabis for private purposes by the Constitutional Court, many concerns have been raised about what this would mean in the workplace. Employers want to know how they will ensure that people do not come to work under the influence of cannabis, while employees fear they could be subjected to unsafe and unwarranted behaviour from colleagues who then attempt to blame the legal use of cannabis at home as the catalyst and expect to be exonerated from their actions as a result.
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ichael Opperman, CEO of Omni Labour Consultants, explains that employers must ensure they have policies and procedures in place to ensure that employees are sober at work. “You have to read and understand the judgment of the Constitutional Court very clearly in this regard. Judge Raymond Zondo said he had “concluded that the limitation is not reasonable and justifiable in an open and democratic society based on human dignity, equality and freedom”. “He then made an order declaring the relevant provisions about the use of cannabis constitutionally invalid where it criminalises the use or possession of cannabis, in private by an adult for personal consumption. It is clear that the private use is allowed and the argument would be about when the use of cannabis is private,” Opperman explains. To start with, “private” would not mean any public place or place of work. At the workplace, the Occupational Health and Safety Act (Act 85 of 1993) and Regulations 1031 section 2 A would apply regarding intoxication. According to section 2A, an employer should not permit anyone who is, or who appears to be, under the influence of intoxicating liquor or drugs, to enter or remain in a workplace. People in a workplace are not allowed to be under the influence of or have in their possession, use or offer other people intoxicating liquor or drugs. Employers can only allow people who use medicine to perform duties if its side-effects do not constitute a threat to the health or safety of the employee or other employees. Therefore an employee, who is contractually bound to the employer during certain hours, has to adhere to the employer’s rules, regulations and policies in the workplace, including undergoing the same or similar sobriety
tests for cannabis as with any other narcotic or alcohol-related transgression. The most important aspect is that employers’ policies should embrace the concept of sobriety in the workplace. There should be a zero-tolerance policy for any use of non-medical, controlled, mind-altering substances. If recent usage can be determined by testing the employee, any employee entering the workplace with a trace of alcohol, cannabis or any other non-prescription drug would fall foul of company policy, as well as the regulations made in terms of the Occupational Health and Safety Act. The same or similar sobriety tests can therefore be conducted in the workplace for being under the influence of cannabis as with any other narcotic or alcohol related transgression. Section 8(1) of the Health and Safety Act states that; ‘Employers should provide and maintain, as far as possible, a working environment that is safe and without risk to the health of their employees. It is common cause that the enforcement of sobriety is reasonably possible’. The consequences for employers allowing someone to work with tools
18 Undercover farming I January - February 2019 I Volume 16 No 1
and clients outweigh the risk of tolerating the use of cannabis at work or its presence in an employee’s system when at work, because the employer carries the risk if anything goes wrong. However, safety is not the only possible motive for an employer to have zerotolerance for alcohol or unauthorised narcotics in the system of an employee at work. Other aspects of working when under the influence of any mind-altering substance include that it could affect an employee’s better judgement in terms of social transgressions, such as bringing the employer into disrepute when inappropriately dealing with a client. There is also the possibility of miscalculating in terms of accounting, stock and design, which could be regarded as not acting in the best interests of the employer, or negligence in performing designated duties. The legalisation of the private use of cannabis therefore does not in any way exonerates employees from their duties at work, the policies applicable in the workplace and the legislation that governs misconduct as a result of being under the influence of cannabis at work. OLC
greenhouses I shade net I hydroponics I aquaponics
Sanitation in the greenhouse – how this can save you money
Sanitation is a term seldom used in everyday life, but is practiced by each and every-one of us on an on-going basis throughout our lives (hopefully!). We are taught basic sanitation from the moment we can remember like, ”Wash your hands before you eat!” and “Brush your teeth!” etc. Even after we die, we are buried or cremated so that we don’t pose a health threat to other people.
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e are fortunate that sanitation (hygiene) is also forced upon us by legislation, for example, most of the water we drink has been sanitised. The main purpose of sanitation in our daily lives is to prevent us from getting diseases. As our population grows larger, the pressure to keep basic sanitary standards high also increases. The same basic sanitary requirements are also applicable to plants. The higher the population of a plant species in a greenhouse, the more important sanitation becomes as a method of controlling plant diseases and pests. Sanitation is an integral part of disease and pest control in any greenhouse situation and furthermore, sanitation must be part of the initial planning. The producer and his team that comply strictly to the rules of sanitation in the greenhouse or pack shed are bound to increase profits. Three basic components must be present for a plant disease or disease epidemic to occur namely a susceptible host, a pathogen and a favourable environment. If any one of these components can be eliminated, the onset of the disease/ pest can be prevented.
Where to start? The first step is to know as much as possible about the pests and diseases that can affect the crop you intent to grow. In the case of a disease, for instance, learn about the primary sources of inoculum, methods of secondary spread of the disease, environmental conditions conducive for disease development and possible methods of eliminating the disease. Not all pests and diseases can be effectively controlled with the use of chemicals. Chemical control is thus not the only control strategy applicable in a greenhouse situation. The chemical representative should not be the sole adviser on all aspects of pest and disease control. The production unit must be as far away as possible from field grown crops. The
Avoid green water on the walk ways.
Sterilize pruning equipment – it is preferable to work with hygienic gloves when pruning.
microclimate of the site is very important. It must be in a place where the wind does not blow very strongly but where there is sufficient air movement to dry off plants. Low lying, damp areas, which are subjected to heavy dew, should be avoided. The same principle applies to a mist belt. Areas that only get sun late in the morning, like southern slopes of hills or on western sides of large trees, should also be avoided. This will ensure that early morning sun will dry off the plants. Planning of the greenhouse The term “crops under protection” can include a very wide range of production methods from crops grown directly in the soil under shade netting to highly
sophisticated closed hydroponics systems where the environmental (temperature and humidity) are automatically controlled. The following are important regarding standards of sanitation and should be taken into account in the planning of the greenhouse: • The layout must favour natural ventilation in all parts of the greenhouse • The greenhouse must preferably have a solid concrete floor with an effective drainage system. • Plant containers (open bag system) must not be placed directly on the floor/ground, but on plastic sheeting. • Drainage water from pots must not be allowed to accumulate or to 21
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Grow media play important part in disease management The importance of grow media cannot be stressed enough as it lays down the foundation for aeration, nutrition and moisture to name but a few. Sawdust and bark both have very low levels of nitrogen (N).
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aving such a deficit reduces the soluble (available) nitrogen supply considerably when plants are grown in either of these two types of media. Even with constant liquid feeding and / or high levels of slow release fertilizers it is difficult to keep up with the nitrogen required by plants in media containing fresh sawdust. Sawdust has a C/N (carbon/ nitrogen) ratio between 250 and 800 with 500 being the average and sawdust would therefore normally be composted to help correct the C/N ratio. During the decomposition process ammonium nitrogen is the ideal nitrogen source for the microbes. The higher the C/N ratio, the longer it takes to obtain a usable end product. The problem is that aeration and drainage properties of sawdust deteriorate with decomposition; finer sawdust needs to be amended to improve aeration and allow oxygen into the root zone. Decomposition of sawdust prior to use is seldom practiced in South Africa and fresh pine shavings and sawdust is still used. Initially such media has good drainage, but deteriorates rapidly as decomposition takes place. The initial decomposition is responsible for nitrogen drawdown that is usually visible in new plantings. A high nitrogen foliar spray at this stage is possibly the easiest way to remedy the problem. The only benefit of sawdust is purely the low cost, but supplies have been limited in recent years and thus farmers are now being forced to find alternatives.
DESIRABLE PROPERTIES OF MEDIAS THAT NEED TO BE CONSIDERED… CARBON TO NITROGEN RATIO
Table 2. Buffer capacity, relative to vermiculite (=100). Figures are for the pH range 4 to 8 Component
Relative buffer Relative buffer capacity capacity Weight basis Volume basis
Peatmoss: Canadian Pinus radiata bark (aged moist for 2 months) - 2 to 5mm Pinus radiata bark (aged moist for 2 months) - 1 to 2mm Pinus radiata bark (aged moist for 2 months) - 0.5 to 1mm Pinus radiata bark (aged moist for 2 months) - less than 0.5mm Vermiculite, exfoliated, 1-2mm Sawdust, composted Eucalyptus spp.
123
2
3
3
7
5
9
16 100 11
43 100 23
BUFFER CAPACITY
AERATION / OXYGEN
Buffer capacity is a media’s ability to resist changes in pH, with some media absorbing the “shock” of an added acid or alkali (base) better than others. The higher the buffer capacity of the media, the less risk there is of pH changes. Sawdust and bark unfortunately do not offer much of a buffer capacity and growers often battle to stabilise media pH. The pH of the water / solution is also critical and may need to be adjusted. The target pH of the nutrient solution supplied to the plants should be between 5.5 and 6.3, while media pH values can change with time depending on the uptake of certain macronutrients. For example, uptake of nitrate (NO3) may lead to an increase in solution pH, due to the plants’ attempt to maintain an electrical charge balance across membranes. A hydroxyl (OH-) ion is exuded upon NO3- uptake, thus a media should absorb the intensity of these types of changes.
In the absence of oxygen in the root zone (i.e. mainly under water-logged conditions) the uptake of nutrients, especially potassium, phosphorous and iron is almost halted and the ability of water to move into the roots is reduced almost threefold. In such conditions, deficiencies are a given, and any deficiency could certainly be detrimental to the health of the plant and will often result in disease. Oxygen diffuses through air 10 000 times the rate at which it diffuses through water, thus waterlogged soils and media are highly undesirable. Oxygen content of a fully aerated solution at 10˚C is 13 ppm and at 30˚C it is 7ppm and although it may not seem significant, the higher the temperature the greater the plants oxygen requirements as respiration increases (Morgan, 2003). Cucumber roots have a high oxygen requirement and sudden temporary wilt, epinasty, of greenhouse cucumber plants is often noted. High solution temperatures also reduce the amount of dissolved oxygen in the solution. Pythium is an opportunistic fungus and often takes hold of plants stressed by a combination of high temperatures and low oxygen levels in the root zone (Morgan, 2003). Oxygen is part of the respiration process whereby carbohydrates are broken down to provide energy for the plant, this being the opposite process of photosynthesis.
Table 1. Approximate nitrogen contents of some dried organic materials Material N in dry material (%) C / N ratio* Pinus radiata bark Pinus radiata sawdust Peat Eucalypt sawdust
150
0.1 0.09 1.5 0.1
20 Undercover farming I January - February 2019 I Volume 16 No 1
500 550 30 500
21
20 WATER HOLDING CAPACITY grow media
Closely associated with the aeration properties is the water holding capacity, which should allow for a “reserve” of water, in turn containing the necessary nutrient for the roots. Aeration capacity requirements vary according to crop, season and container size, remembering that long-term crops often battle towards the end, as the mediums properties are lost over time. Alcohol, hydrogen sulphide and ethylene are produced in the roots and hormone production is upset in waterlogged soils and media. Toxic levels of iron and manganese are also associated with waterlogged mediums and the combined effect of excess water and poor aeration is seen as stunted or wilted tops, root death is often evident and roots will often be at the surface of the media where oxygen is available.
CEC A media with a high CEC (cation exchange capacity) does have merits as it allows for less nutrient leaching and less frequent nutrient applications. A desirable media with a high CEC could almost be seen as a reserve or nutrient store and may lead to savings in fertilizer usage. Coir, peat and vermiculite combinations are possibly the best options for enhancing CEC.
STERILE Media such as coir and imported peat are sterilized prior to importation and Sanitation in the greenhouse
greenhouses I shade net I hydroponics I aquaponics
thus a grower is guaranteed of a pathogen free media. Media such as peat and coir often contain tannins and lignins, which help suppress disease and keep the media stability.
pH The desirable pH of a media should be 7 or slightly below this, ensuring optimum nutrient availability. Extremes of pH lead to nutrient imbalances, causing either toxicities or deficiencies. An excess of one element is often then antagonistic with another element, exacerbating the nutrient problems.
MEDIA STABILITY
Sawdust is often used by start-up greenhouse operators, but other media discussed in the editorial may offer better long term solutions.
Mixed media; bark mixed with vermiculite or perlite offers longevity.
Longevity of grow media is vital, although the appearance may not change in certain medias; the properties mentioned above are the best indicators of the true
longevity. Media such as coir last for many years and are highly suitable for longterm crops. Stability saves on labour and reduces the incidence of disease.
19
flow from one container to the next. • Sufficient space between rows must be allowed for workers to move freely between benches without touching the plants. • A wash basin must be available for workers. • Growth medium must be stored in a closed place with a solid floor. Precautions must be taken to avoid contaminating the medium with soil. • A place, well away from the greenhouse must be allocated where plant debris and old plants are destroyed. A reliable water source must be available. Borehole or municipal water is preferable, but if other sources are used, water must be sanitised. All water must be stored in closed tanks, not in open dams. Access to the greenhouse must be restricted, and a foot dip, containing a disinfectant, must be installed at the entrances.
One mistake by one person can cause a disease epidemic. The selection and training of the people that word in the greenhouse is key to success of the greenhouse operation. The workers are the people that must practice day-to-day sanitation measures. The disinfection of equipment is critical, but the workers must also be equipped with disinfectants/ detergents and wash facilities to minimize the spread of disease. The most successful operations are neat and have well trained personnel. A set of written sanitation guidelines is perhaps the most efficient way to get every worker familiar with sanitation measures. The manager must be familiar with these guidelines and must set a good example to the staff. The practise of sanitation must become a habit. Signs can be used to remind employees about the sanitation programme. Workers should not be allowed to grow the crop in their gardens, as it can be a source of contamination.
Sanitation in the greenhouse The primary inoculum source depends on the disease. Some diseases are air-borne, others are water and/or soil borne, while some are transmitted by insects. Many diseases are disseminated through seed or other propagation material. The seed source must be very reliable. In the case of bacterial diseases of vegetables, warm water treatment of seed is strongly recommended. This treatment should be done by a reliable laboratory. The other sources are eliminated or kept at a minimum by measures already mentioned. All steps must therefore be taken to prevent possible introduction of the pathogen into the greenhouse. It is therefore important for every producer who wishes to send quality produce to the market to uphold sanitary measures in the production area and remind staff continuously to stick to these disciplines. Source: ARC – VOPI
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Marketing strategies for a greenhouse operator Consider two small towns: Each has an established small greenhouse grower and all of a sudden a chain store with national buying power arrives on the scene. A few years later, one grower is bankrupt; the other grower is surviving and thriving!
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hy did one grower finally give up and close? How did the other grower not only survive but also thrive in the shadow of a big economic role player? To answer these questions, in our country, or in the province you intend doing business in, at least a hundred willing greenhouses, garden centres and nurseries should be contacted or visited to collect information and data, their point of view how they achieve success in order to put together a meaningful strategy for the smaller greenhouse operator to survive. Data and information collected, including marketing strategies, maintenance of market share, promotional plans and programs, product mix, value-added ideas, advertising, demographics, pricing policies and market channels could be put together in a forceful presentation which can be presented at the Undercover Farming Conferences and other fresh produce grower organisation meetings. This will greatly add value to the industry.
The objectives of the exercise:
competitor. These research results will change the thinking of many newcomers and small to medium greenhouse growers in the country with magnificent results right down to job creation. These growers/ producers have to formulate their own strategies, concepts and ideas to not only survive but thrive in the current, competitive greenhouse industry market.
The Right Strategy
• How small growers (wholesale and/ In conversations with small and medium or retail) cope with current trends growers, perspectives will change the and changing customer preferences. mind-set from complacency, denial • How small growers compete against and even panic to the big chain The grower should confidence and stores. optimism. The understand the value • What lessons successful growers of customer service and growers can learn will come to terms from the research pampering. Continuous with the reality of a results. telephonic and even changing marketplace. • How growers can better, physical visits They have accepted incorporate these that big operators to their niche market is results into their are here to stay and important. existing marketing learned that the programs. changing market demands different • What happens when a big chain store responses. When a big operator appears moves in? on the horizon, smaller growers most • How small growers react and the commonly choose either a “snooze and strategies they develop. lose” or “change and prosper” strategy. • How the chain stores have forced Many wonder if chain stores are a help small growers to re-think their or hindrance to the industry. The big marketing strategies. boxers push prices down and keep • How growers can survive and thrive prices down, sometimes below the in the shadow of a big greenhouse break-even costs of some producers.
22 Undercover farming I January - February 2019 I Volume 16 No 1
Successful growers are competing by returning to some marketing basics.
The most common success strategies are: • Knowing and understanding production costs. • Planting what is profitable versus what the grower likes. • Developing a niche. • Having a positive attitude. • Listening carefully to what customers want. • Adding value and service. • Making buying into an experience. The grower should understand the value of customer service and pampering. Continuous telephonic and even better, physical visits to their niche market is important. Having a selection of greens or other fresh produce rather than producing one type ensure you are always in demand (and in business). Last but not least, it is of essence to listen to public, what they eat, seek new product avenues that are already in demand (the small grower cannot afford growing for research purposes). Be positive about the global move towards green foods and the escalating demand for it. (This is an edited viewpoint for the local undercover producer from a write-up by Robin Brumfield and Lawrence Martin. Ed.)
greenhouses I shade net I hydroponics I aquaponics
Quality and quantity assurance with rootstocks The use of grafted plants has been common practice all over the world. Breeding rootstocks was really commenced in the 1960’s and mainly focused on cold tolerance and disease resistances. With the introduction of substrate growing in the early 70’s, the interest for grafting decreased.
I
n the 1990’s a new grafting technique was “discovered” in Japan and quickly adopted in the Netherlands by the plant raisers. Nowadays even grafting machines are used by the most advanced nurseries.
Efficiency in quality food production Producing worldwide enough quality food is an issue much discussed; the world population is growing fast, whilst the availability of good water sources reduce. This means automatically that the use of more efficient production methods will increase. More open land farmers of vegetables, fruit, berries and nuts are turning to either greenhouse our multispan net houses to obtain higher yields per m², and the use of water becomes more efficient by using advanced technologies, therefore the overall quality of the fruits improves as well. In the past greenhouses have been disinfected with steam or Methyl Bromide, nowadays steaming becomes too expensive while Methyl Bromide is forbidden. The combination of these facts has boosted the worldwide use of rootstocks.
Grafting Grafting onto a resistant rootstock is not only used as a precaution against soil diseases. Stronger growth and resilience have become as important and reflected
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foliar sprays in perspective page 20
family farm produces Quality cucumbers page 4
in a high plant quality and a higher total production. If grafting tomatoes, aubergines or peppers, the choice of the rootstock depends on the growing power and desired resistance, but also on the duration (length) of the growing period. It may take many years for breeders to incorporate complex tolerance or resistance into cultural varieties, without loosing other favourable characteristics of the cultural variety. The use of a rootstock is a faster, and often more effective way to prevent disease in the crop, allow crops to grow in cooler/or warmer conditions and give the breeding company more space to concentrate on other traits in the cultivars such as fruit quality aspects and other not soil born disease resistances. In rootstock development segmentation is as important as in development of usual varieties. Improved Nematodes resistances in combination with weakmedium- and strong growing rootstock varieties are produced. It is very important to learn how to handle a very vigorous rootstock - if you are able to control the balance in your crop you will definitely reach the highest yield. It is advised for growers to start with a medium vigour rootstock and after a few years of experience start to use a more vigorous rootstock. .
Cherries and other small fruited varieties are often grafted on less vigorous rootstocks because the plants of these varieties are usually already quite vigorous themselves. Plum cultivars, which are highly likely to battle with Blossom End Rot needs a medium vigour rootstock with extra F3 resistance. The first generation of tomato rootstocks often had germination problems; currently germination is improved through priming, which offers not only a higher germination percentage but also a more uniform germination.
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