Undercover Farming Magazine March / April Issue 2020

from Undercover Farming Magazine March / April Issue 2020

by Undercover Farming Magazine

Undercover Farming

March/April 2020, Volume 17 No 21

markets & COVID-19

measuring leachateCalcium in the plant

aquaponicsFresh Produce Markets, Suppliers & Retailers vs Covid-19 Page 4

How to Manage Irrigation by Measuring Leachate Page 8

How Calcium Influence Optimum Production Page 14

Aquaculture: Industry with Great Expectations Page 18

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Contents

4 Fresh Produce Markets, Suppliers & Retailers vs Covid-19

6 The Flower Industry in South Africa & Europe during Covid-19

7 Plaasvars e-Market for farmers launched by TLU SA

8 How to Manage Irrigation by Measuring Leachate

10 Biological nitrogen fixation instead of nitrogen fertilizers

11 Lockdown sees uptick at regional fresh produce markets

12 REVIEW: Undercover Farming expo & Conference 2020 Pretoria

14 Calcium & your plant – how it influences optimal production

16 Act 36 of 1947 – What does the law say about fertilizer?

18 Aquaculture: Industry with great expectations

19 Novel equipment: Farmers urged to de-silt reservoirs before dry season

19 Subscription form

FRONT PAGE: An interesting display of peppers at a supermarket. The slight opening of lockdown largely assist necessities to reach retailers and keep producers going. Read more what is happening in the fresh produce industry in this edition.

INSIDE ...

11 14

A Scripture in tough Times...Isaiah 43 See my servant whom I uphold: my Chosen One, in whom I delight. I have put my Spirit upon him; he will reveal justice to the nations of the world. He will be gentle – he will not shout or quarrel in the streets- He will not break the bruised reed, nor quench the dimly burning flame. He will encourage the fainthearted, those tempted to despair. He will see full justice given to all who have been wronged.

The most recent Undercover Farming Conference held in Pretoria once more proved there are people in our country and adjoining states that are truly inspired by what they hear and read about hydroponics systems under protective cover. There are open land producers also turning towards undercover farming practices in order to enjoy the benefit of year-round production to captivate their markets. The mere fact that attendees in between presentation sessions actively visited stalls for further information, confirm the steady growth in numbers of producers. The Covid-19 virus and lockdown strategies we have to bear with currently bring along its own challenges, although markets are still being fed with produce as supermarkets require fresh produce. Certain limitations in movement, controlled hygienic measures and a bevy of other restrictive measures incur food outlets still to be closed. It is understandable that many of us do not comprehend the level of certain measures that are at sometimes being forced by police or defence subjects on public in a ‘draconic’ way. Fortunately most of these are recorded and being discussed at high level. May we all strive to remain calm and collected through the lockdown months. In this edition we touch on a few subjects of practical interest and we thought it well to obtain viewpoints from leaders in the formal fresh produce market sector. As one browse for news on fresh producer situations in other countries, it is clear that everybody experience the same hurdles and only our faith, cooperation and novel thinking around our businesses will lead us through this period in our life. We wish everybody success and, when talking to your neighbours, try to steer away from negativities and rather put heads together to find ingenious ways to survive in your production systems!

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How can the producer currently get his product to the market/ distribution warehouse and what requirements does he need to comply with? Francois: “The normal procedures as before the infringement still apply. On-going communication between producer and his agent/agency on volumes available/required is necessary. Loading-off procedures at all the Markets remain the same (also the required documentation). “However, there are certain aspects of which the farmer should take note:

• My personal advice is that every farmer/transport handler/third party involved with the logistics of a consignment must have to address hygiene (Covid-19 protocol) at all times

• There must, throughout the value chain, be complied with the necessary measures to limit the infection of the Corona Virus as far as possible

• An enormous issue that transporters face is inter-provincial transport – in short, transport across provincial boundaries (for this, special permits are necessary – the Department of Trade and Industry (DTI) should be contacted (preferably on their website) – also the agent and the market authority for assistance concerned herewith

• Producers and transport companies must ensure that they have all permits and authorizations before they leave their premises with a load – they also need to register their staff (drivers and truck assistants) and provide the necessary documentation – it should include a letter from the producer as the employer

• Products in particular must also comply with “top” quality standards – this is not yet addressed in depth but currently discussed. The impact of the product (packaging) as a

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Fresh Produce Markets, Suppliers &

Retailers vs Covid-19

In a world of lockdown because of Covid-19 virus, populations are mostly indoors and very probably are more prone to consume more foodstuffs. This calls for an on-going supply of food of which fresh produce and meats are important substances. But there are so many questions in the mind of the producer, his workers, market agencies, logistics companies and retailers carrying with it uncertainties regarding hygiene, distancing whilst still trying to retain a fair market share or at least have the farm or business holding its own. Undercover Farming turned to Francois Knowles, Registrar at the Agricultural Produce Agents Council (APAC); a person with thorough knowledge and years of experience in the fresh produce industry, to offer readers advice on the current affairs.

“vehicle” to distribute the virus is being investigated,” Francois explains. The requirements set by government for the farm/production unit as far as the process of planting, cultivating operations, harvesting, packing and dispatch boils down to the focus on confidence of the previous role player along the chain. “In short, as each role player subject himself to the necessary regulations (under the Covid-19 protocol), the distribution of the virus will be limited. This is of no value if the market, as sales platform does everything in its ability to secure products and the process on the farm or transport lacks cooperation. In short, everyone has to cooperate to keep the value chain underway – the current process is effective – maybe just slowing down,” Francois mentioned. On the question whether the large markets operate at all, or do the market agents still handle produce from farmers and arrange that fresh produce is picked up by chain stores’ distribution centres? Francois replied; “Here the situation is very interesting. In the last week of March 2020 (when the lockdown was instituted) we saw a measure of panic purchases. The figures for national Markets grew year after year from R1 354 Billion up to R1 403 Billion (3.58% in turnover and 1.82% in volumes). It is difficult to ascribe it directly to the last week (of March) or

so, but we are investigating the cause. The important message here is that the markets function well – all of them. This is due to the fact that agriculture was initially identified as an essential service because of food security. In terms of the figures there was a decrease in April 2020 – and it is important to take note of the following:

• Informal traders may trade again, restaurants and “fast food outlets” are closed – hence a decrease in that particular business – a good example is potatoes – large is R4 less than last year because of this

• I believe that the panic has scaled up and markets perform normal in the “new normal”. “Stringent hygienic rules are followed during the process of farm to mouth to ensure continued quality and hygienic standards. IMASA (which represents market agents) has compiled a Covid-19 Protocol that has been made available to all markets. The following are some examples:

• The issuing of personal protective equipment (PPE’s) such as marks are crucial to market agents and staff working at a market

• Market agents in collaboration with the market authority immediately decided to emphasise the cleaning of all sale floors (including cold rooms)

• Ablution facilities are a

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Covid-19 4

primary focus and it is non-negotiable – market management teams will have to show their steel by enforcing hygiene practise in all spaces

• At all sales points, market agents have disinfectants that they use when dealing with clients (these are proper sanitizers used to keep hands clean)

• Market management also have disinfectants strategically placed over the rest of the market – especially at payment points

• Payment points, where cashiers are working with cash, are issued with surgical gloves. The contact with clients is also limited by a glass window or cubicle

• Buyers on the market floor will also no longer be allowed to feel, taste or touch products – they will have to buy with the eye

• Very important, is that all market role players will have to maintain a safe distance from each other (contact with each other should be avoided at all costs)

• It is very important to distribute this important information – it will therefore be strategically placed on notice boards where people pass by or work and notices are printed in different languages to inform buyers and market users of the hazards and new rules – the biggest message, is of course to keep your hands clean and wear a mask.

According to Francois Knowles, the critical success in this time depends on good communication. “We see this with the President who keeps us informed continuously – we need to do the same in agriculture and the complete food value chain. If everyone knows what to do, where to call for information or assistance and realise what is expected from the

individual, accepting our situation will have people’s moods become more at ease – South Africans are strong people and we know how to get through difficult times. “I work closely with IMASA (agents), Market Authorities (25 in total) as well as the following role players: AgBiz (I am part of the Ministerial Task Team) that offers advice on Covid-19 to the Minister, AgriSA, Potatoes SA, PMA, Department of Agriculture and various other important role-players who together with APAC, together play a leading role within its mandate – it is still to support producers in the midst of this very hard time. We continue to maintain our focus in all aspects to support our agents in the process,” Francois explains. How can the producer position him to attain full production as quickly as possible after Covid-19 in order to supply at a normal scale to the market and therefore delivery to retail outlets? The answer is simple: Firstly, speak to your agent constantly (trust him in these times), obtain all possible information available – be wary of fake news and don’t re-act impulsive – things will normalise – we just have to get through the pandemic. Also, make good decisions on the best information available – remember to talk to APAC about any aspect that you are not sure about (or want more information). Job creation in times like these remains a challenge – especially now with the Corona outbreak. Workers come from townships and cities and have the possibility to bring the virus to farms via their families or fellow workers. Farmers therefore have an important task at hand to institute necessary safety and hygienic measures to ensure that visitors or co-workers will subject to a farm’s protocol (sanitizing them at gates, giving them the necessary PPE – safety clothing, keeping social distances etc.).

Hygiene principles are followed to protect the whole value chain of fresh produce.

In terms of food wastage, APAC believes that communication with agents can better address potential wastage – the agent must correctly inform the farmer about supply and demand and what is truly necessary. Long queues for fresh produce and a full market floor, in times past indicated the success of the agent. The “new norm” is to ensure that we pursue food security. In terms of organising possible waste (fresh produce); at the beginning of lockdown, the task team were duly informed to avoid fresh food waste at all cost. People who are hungry will do anything in their means to lay their hands on even waste – thus furthering risk to people’s health – a situation the markets simply must avoid. The focus on produce sold via markets slowed down but the primary items such as potatoes, onions, tomatoes, cabbage and vegetables are still arriving. Fruits are now luxurious and are probably sold a little less. But fruit can be stored easily in cold rooms. Potatoes used by restaurants and take-aways (for chips) declined for the first three weeks, but there is an incline as some restaurants, although doors are closed for public, offers delivery or take-away meals. The lockdown also has a benefit – people now opt to eat healthier – it also creates an opportunity for new and creative business (people who purchase and distribute – a type of “Uber delivery”). “Our lives will never be the same. Hygiene and washing hands and face, wearing masks became part of our life. But here is the positive I see and we must never forget it: We know what we are working with – the Corona virus (the AIDS virus in 1981 took 2 years before it was correctly identified), we can diagnose the virus, it’s going much better in China – this proves that we can overcome it, 80% of all cases are mild and people are healthy, children in general, show only mild symptoms. We therefore know where the crisis is, we can manage the virus infestation – with hygiene and by proper distancing. The whole world works for a solution – it’s a matter of time. There are already vaccine prototypes and antiviral trials that are underway”. “The future of our agriculture is bright, yes, we have a crisis currently, but we must learn from our mistakes and do things better. This test is probably one of the worst and more serious ever experienced before – but I believe without a doubt that we will overcome every obstacle in due course to still feed our nation,” Francois Knowles concluded.

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Will flower producers adapt to change?

The 5 weeks lockdown has played havoc in the flower industry and most have lost a great deal of money. Fortunately, government has listened to the many presentations from SAFGA and SAPPEX that the floricultural industry should not be regarded as non-essential. A bunch of flowers or a lovely pot plant brings joy and peace in the house, especially for those, old and young, who are restricted to their places of residence.

The Flower Industry in South Africa & Europe during Covid-19

Multiflora, the flower market

will re-opened on 1st May, which is great news. It must be accepted that the startup will initially be slow. However, a plus point is that it came just in time for the Mothers’ Day trade. It will take time for the floriculture trade to return to levels it is used to. “We hope and pray that the overall recovery in our country will return to normal levels in the near future,” says Jac Duif, chairman of SAFGA..

“Besides the efforts of the SAFGA team, we owe our gratitude for those persons and organisations who assisted our industry with lobbying with the ministers concerned. It is my wish to mention the people and organisations who assisted us in many ways, to name the few I am aware of: Geert van Geest of LVG Pot plants, Miriam Ngoato-Breg of AFG-Worldwide, AgriSA, Woolworths, Nedbank and Multiflora and our secretary who kept the lines open. Also a word of thanks to Welma Viljoen of Mobjadi Nursery who assisted us with the UIF matters. “It is unfortunate that in the near future we cannot have our get-together growers’ days. We will keep you posted in the future on all matters which concerns our industry,” Duif concluded. Flower sales online, the future? From an editorial in Floraculture International May-June 2020, an interesting shift in ornamentals marketing comes to the fore. Can this be established in South Africa as well?

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Bloomon is an online company that has field fresh bouquets delivered directly from local (Netherlands) growers. It is a subscription service offering free delivery to the customer’s door, which is their strongest sales proposition. Initially, a startup, backed by significant private equity funds in its early days, Bloomon has now a market presence in the Netherlands, Belgium Germany, Denmark and the UK, selling around 1.5 million bouquets a year and employing 80 people. CO Bart Troost says, “We have seen a significant increase in orders over the past two weeks with a 50 per cent spike in sales in all five countries. Our customers are clearly in need of flowers for their home and home office as they are spending significantly more time inside. But a significant proportion of bouquets are also ordered to surprise beloved ones. It is without substantial evidence that flowers and plants do trigger happy emotions.” FCI was keen to find out how bouquet subscription services are dealing with

Where have all the flowers gone? A sorry sight; to any flower producer and home maker. May we have the South African flower industry re-established soon!

the current situation. What are the challenges? How have they found a way through them? Vital to Bloomon’s success is a flexible subscription service, with customers deciding on the frequency and time of deliveries and the bouquet size. Customers can also order single items including fresh-cut flowers, dried flowers and gift vouchers. “Flower growers are currently going through a challenging time,” says Troost. However, Bloomon is happy with its increased online flowers sales, which are helping to provide growers with a market outlet in these incredibly difficult times. Troost says that during this busy period it’s all hands-on deck. “Especially, since we are strictly adhering to government regulations. Where possible, we have been hiring extra people or asking

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TLU SA launched the Plaasvars e-Market to link farmers and consumers with each other.

Plaasvars e-Market for farmers launched by TLU SA

TLU SA launched the Plaasvars

e-Market to link farmers and consumers with each other.

“The commercial farmer gets the short end of the stick every time it gets to funding from the state,” says Mr Louis Meintjes, the president of TLU SA. “No support during droughts. No help during disasters like COVID-19. No support when bank loans get too high to pay off.

“Small-scale farmers – who produce less than 2% of agricultural products and employ only 6% of workers – get lifeline after lifeline. Big farmers can absorb disasters easier because of government

contracts and financial prosperity. But, the impact when these farmers fail, is also so much bigger,” he says. The commercial farmer is the key to food security. TLU SA looks after the commercial farmer. The farmer working day after day to secure an income for farmworkers, their own families and, most importantly, sustainably produced fresh products. “We have seen the need for a platform where farmers can get in contact with consumers directly,” says Mr Meintjes. “In this way, they can continue to make a living during challenging times.” Farmers can sell any agricultural product

on the digital selling and buying platform. With TLU SA’s Plaasvars e-Market consumers can speak directly to farmers about their products.

The platform is easy to use:

• The farmer loads the information and available products with a photo or two;

• The consumer visits the market and view the products they are interested in; and

• The farmer and consumer speak directly to each other to complete the transaction.

The Plaasvars e-Market is available at this link: https://plaasvars.tlu.co.za/

The Flower Industry 6 colleagues from the office to help with customer service and making bouquets.” Troost is happy to share a few tips with other flower delivery companies. “Take along your team. Explain what you want to do, why it is so important for the company and society. And communicate even more than you normally do. We,

for instance, have daily updates on key metrics and initiatives and a weekly update from the management team. About the long-term effects on the floriculture supply chain, is still a bit too early for predictions. However, there are two areas where we anticipate change. We know that all growers are struggling to keep afloat but for smaller growers the

challenges may be even bigger. “I hope that these small growers will be able to survive and keep producing speciality flowers. Meanwhile, the question is how the coronavirus pandemic is changing consumer behaviour. COVID-19 could well accelerate a consumer shift to buying flowers online,” Troost concluded.

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How to Manage Irrigation by

Measuring Leachate

The management of undercover farming irrigation is very difficult since there are numerous factors that influence management decisions. These factors include: the composition of the substrate, container size, plant species and size, plant nutritional requirements, weather, type and condition of the irrigation system, and the quality of the water that is applied.

Soilless substrates (i.e., growing

media), by design, are tolerant of over-irrigation. Soilless substrates have high porosity, but little water retention when compared to soils. Furthermore, only half to two-thirds of the water retained in the substrate is available to the plant to use.

Since the risk of overwatering is low, growers tend to irrigate frequently with excess water to avoid plant water stress. However, fine tuning your irrigation can lead to numerous benefits that include: conserving water, reducing energy and fertilizer usage, reducing runoff that contains pollutants, and improving plant health and quality.

When fine tuning your irrigation schedule, the amount of water you irrigate needs to, at minimum, replace the water that is used by the plant (transpiration) and evaporated directly from the substrate into the atmosphere (evaporation). The sum of these two water losses is “evapotranspiration.” Water quality must also be considered since water includes salt in additional to the mineral nutrients (i.e., more salts) from your fertilizer.

Plants will use the majority or all the available water in the substrate; however, they will be selective when taking up salts creating a build-up of salts over time. This becomes worse when water quality is poor or if fertilizer is over applied. An additional amount of water needs to be applied during each irrigation cycle to “push” these salts out of the container (Figure 1).

This article provides details of on an-easyto-use method to measure leaching

fraction to better schedule irrigation and avoid the salt build up that can be detrimental to your crop.

WHAT IS LEACHING FRACTION? Leaching fraction is the ratio of the volume of leachate to the volume of applied water. The applied water is equal to that received by a container. The leachate is the amount of applied water that enters the substrate, flows through it, and exits through the container drainage openings. This is typically determined daily, regardless if irrigation is applied once or multiple cycles each a day. The leachate, or drained water, carries away the salts that were in the substrate water in the container.

WHY MEASURE LEACHING FRACTION? Leaching fraction tells you if you are applying too little, too much or just the right amount water when you irrigate.

The method considers the water use of the crop, effect of the crop canopy and substrate properties. If you have or are prone to salt issues, measuring the leaching fraction will also inform you if you are adequately applying enough water to leach salts that are accumulating in the substrate. The build-up of salts may slow crop performance or cause damage to the plants. There are two ways to measure leaching fraction.

HOW TO MEASURE LEACHATE BY VOLUME With overhead irrigation, to measure the leachate from planted #4 size containers or smaller, you will first need to modify the lid of a 20 litre bucket. Larger plant containers will require larger capturing containers and lids. Cut an opening in the lid so that either an empty or planted container will nest into the opening on the lid of the container. Make sure there

Figure1. Enough water needs to be applied during each irrigation cycle to replace the water transpired and to provide adequate leaching.

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Measuring Leachate 8 is a snug fit between the opening in the lid and the container to ensure water does not leak into the bucket.

Putty, caulk or other material can be used to make sure water does not flow from the lid into the bucket. When the lid and plant are placed on a bucket, only the water draining out the bottom of the plant container should be collected, and the water that does not enter the substrate should be excluded. An empty plasticlined container of equal size to the planted container or a second bucket with an empty container is placed near the plant container-in-bucket set up.

An electronic nutrient leachate measuring system in a tomato greenhouse.

Irrigate normally when needed; wait about an hour to allow the excess water to drain from the substrate. Use a graduated cylinder or other measuring cup to measure the volumes of the water collected in the buckets. The water from the empty container represents the amount of applied water and the water from the planted container is the leachate amount.

Calculate the leaching fraction by dividing the leachate volume by the applied water volume.

Leaching fraction = leachate volume ÷ applied volume

The volume method can provide leaching fraction values greater than 1.0 or 100% leaching since the canopy of the planted container can collect more water than an empty container. This occurs when plant canopies are greater diameter or taller than the empty, lined container. The weight method described below

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will always provide a leaching fraction between 0.0 and 1.0. If using a drip irrigation or spray stakes, a pan under a raised container and milk or juice jug can be used to collect leached and applied water.

MEASURING BY WEIGHT FOR ADDITIONAL INFORMATION A scale can be used to easily convert weight in grams to volume when it comes to water (1 mL = 1 gram). When using the weight method, first separately weigh: 1) the empty bucket and 2) the planted container before the plant needs to be irrigated (Figure 4). Place the modified bucket lid on the bucket and then nest the planted container in the lid. Make sure that water that lands on the lid will not be able to drain into the bucket. Place the planted container and bucket in the irrigation area. Complete an irrigation event and then wait about an hour to allow all of the water to drain from the substrate into the bucket. Remove the irrigated plant from the bucket and re-weigh it, then weigh the bucket with the collected water. Subtract the pre-irrigation weights from the corresponding post-irrigation weights. What you will determine: 1. Water retained by the plant = irrigated plant – “dry” plant 2. Leachate volume = bucket with water

– empty bucket

3. Applied water volume = water retained by the plant + leachate volume

4. Leaching fraction = leachate volume ÷ Applied water volume

CONCLUSIVE INFORMATION For most levels of salinity of the production system (water, fertilizer, substrate), a leaching fraction of 0.20, an amount equivalent to 20% of applied water draining from the container, is necessary to ensure you are applying adequate amount of water and leaching any excess salts. If the electrical conductance (EC) of your water, including nutrients for liquid feed systems, is greater than 2.0, then a leaching fraction of 0.30 is required to leach the additional salts. If the total salinity is less than 1.0, then a leaching fraction of 0.10 is sufficient. If the water quality is very poor, you may also want to look at treatment or blending higher quality water to lower the salinity. Information regarding this can be found at the CleanWateR3.org website, from literature on the topic, or your cooperative Extension agent or specialist.

Figure 2. Buckets are used to capture applied irrigation water and leachate. The plant container needs to nest in the opening of the bucket lid. The mating between the container and lid should not allow water to enter the bucket. Putty or caulk may need to be used to exclude the water.

When the leaching fraction is greater or less than optimal, you will need to adjust your irrigation duration. The closer you are to the target, the more accurate each adjustment is. An estimate* of the adjustment to the runtime can be calculated by:

TA = t × (LFT – LFM)

Where:

• TA is the time adjustment

• t is the current duration of the irrigation

• LFT is the targeted leaching fraction

• LFM is the measured leaching fraction

• *This is a simplified version of the actual calculation

OTHER BENEFITS A benefit of using the bucket method for plants irrigated by overhead irrigation is that the leachate represents the amount of water that actually enters the container, and it takes into consideration both the water that lands directly on the substrate and the water that is intercepted by the plant canopy.

This is important because the architecture of the canopy could either direct the intercepted water into the container (for example, a vase-shaped plant) or the water could be shed away from the substrate surface (an umbrella-shaped canopy with broad leaves, for example). A simple pruning can have a dramatic effect and result in a change in the amount of water applied.

Measuring leachate can be a good tool to determine if the proper amount of water is applied at each irrigation cycle to control substrate salinity. It is quick, inexpensive, easy to do and will provide the information you need to be a better irrigation manager. Using the information gathered can reduce water use, improve nutrient use efficiency and reduce run-off. L.R. Oki and James S. Owen, UC

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Biological nitrogen fixation instead of nitrogen fertilizers

Over the past decades, crop yields have increased substantially, occurring alongside the increasing use of nitrogen fertilizer. While nitrogen fertilizer benefits crop growth, it has negative effects on the environment and climate, as it requires a great amount of energy to produce. Many scientists are seeking ways to develop more sustainable practices that maintain high crop yields with reduced inputs.

A more sustainable way to provide nitrogen to crops would be through the use of biological nitrogen fixation, a practice well developed for leguminous crops is the meaning of plant pathologists. A variety of nitrogen fixing bacteria is common in the rhizosphere of most plants. However, such plant growth promoting bacteria (PGPB) have seen only limited use as inoculants in agriculture. However, this limited use is possibly the cause of general problems associated with the use of biologicals for crop production and variable efficacy upon application. Research was done to gain a greater understanding of the metabolic response of the plant host in order to reduce the variability seen with the response of crops to PGPB.

The challenge with the research was, while PGPB can colonize roots to high levels, the sites of colonization can be highly localized. Thus, isolating whole root systems result in a considerable dilution of any signal due to the great majority of the root cells not in contact with the bacteria. To overcome this challenge, the research team utilized laser ablation electrospray ionization mass spectrometry (LAESI- MS), which allowed them to sample only those sites infected by the bacteria, which they could localize due to expression of

green fluorescent protein. Their results showed that bacterial colonisation results in significant shifts in plant metabolism,with some metabolites more significantly abundant in inoculated plants and others, including metabolites indicative of nitrogen, were reduced in roots un-inoculated or inoculated with a bacterial strain unable to fix nitrogen. It was found compounds involved in indole-alkaloid biosynthesis were more

It was interesting not to find a significant impact on phyto-hormone production that correlated tightly with the ability of PGPB to enhance plant growth.

abundant in the roots colonized by the fix-strain, perhaps reflecting a plant defence response. Ultimately, through such research, itis hoped to define the molecular mechanisms by which PGPB stimulates plant growth so as to devise effective and consistent inoculation protocols to improve crop performance.

It is believed that, in contrast to other better studied interactions, such as rhizobium-legume, this is due to a general lack of information about the molecular mechanisms by which PGPB stimulates plant growth. Hence, in the laboratory projects that seek to provide this information, is the belief that such information will increase the efficacy of PGPG inoculants with the net effect to increase their use for crop production.

It was interesting not to find a significant impact on phyto-hormone production that correlated tightly with the ability of PGPB to enhance plant growth. This suggests that PGPB impacts plant metabolism to a greater extent than previously realized, thus pointing perhaps to more complex explanations for how these bacteria impact plant growth. SU.

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Business is booming at some of South Africa’s regional fresh produce markets, as South Africans take advantage of the opportunity for direct, cost effective access to fresh fruit and vegetables...

Shelves will be full again while customers and staff at retail outlets abide by the hygiene rules.

Lockdown sees uptick at regional fresh produce markets

‘Both our RSA Vaal and RSA

Nelspruit operations surpassed their monthly sales record on the 21st of April, with eight trading days still to go,’ says Luan Wentzel, Managing Director RSA Tshwane and RSA Regional Markets. ‘Current estimates also indicate that Polokwane will surpass its April record by at least 10% at month end. Mooketsi market isn’t in line for a record but is performing at similar levels to last year.’ South Africa’s fresh produce markets generally operate in the background of the national food supply system, but since the lockdown they have seen an influx of private buyers in addition to retail buyers and members of the country’s vast network of informal traders. ‘Numbers are almost impossible to define, especially because lots of different groups pool resources for group buying, but the feedback from our agents clearly shows that there has been substantial increase in the numbers of people buying for personal use compared to prelockdown,’ says Wentzel. Growth in the number of private buyers

illustrates the flexibility of South Africa’s fresh produce markets, which not only form a crucial part of the national food supply chain but also offer a valuable alternative to people who live far away from supermarkets, or who no longer have access to street hawkers and informal traders. ‘Supply is strong, and our farmers are producing well, but there is no doubt that certain parts of the country are challenged in terms of access to food andfresh produce,’ says Wentzel. ‘The markets are performing a crucial function in this context, and RSA Group is doing everything it can do make sure all buyers have the support they need.’ RSA Group is the largest fresh produce sales agency in the country. Decades of experience operating at South Africa’s fresh produce markets means it is an ideal position to support newcomers to the system. The company is currently helping buyers

‘The new visitor’s experience features thorough safety protocols throughout, which creates a sense of security and sees more buyers arriving to purchase fresh produce at the facility.’

who ask for assistance obtain the permits they need to officially procure and transport produce during lockdown. RSA Group has also collaborated with Freshlinq

Luan Wentzel, Managing Director RSA Tshwane and RSA Regional Markets

(which manages the regional markets and their data systems) to implement the access control and social distancing measures necessary to ensure the safest possible environment for buyers and traders on the floors.

‘A strong health and safety approach creates trust in the system and processes, and makes the facility easy to use. This is very important in the context of the pandemic,’ says Wentzel. ‘The new visitor’s experience features thorough safety protocols throughout, which creates a sense of security and sees more buyers arriving to purchase fresh produce at the facility.’

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Review: Undercover Farming Expo &

Undercover Farming Expo & Conference was presented 24 and 25 April 2020 at the CSIR International Convention Centre, Pretoria. Looking back over the past event, our loyal exhibitors are satisfied with the business opportunities and delegates with the quality of speakers over and above the ample time allowed for networking with professionals in the trade, which again this year was a great success.

“Our registered delegates

for the conference were 170, of which 70 were small commercial farmers. The Day visitor registrations and casual visitors at the conference totalled 1 250 visitors, which included high profile visitors such as the High Commission of Iran, The Agricultural Counsellor of China and the Denmark Trade Commission, reported Undercover Farming Director, Suzanne Oosthuizen.

“The focus set for the 2020 event was on the quality of technology with which greenhouse producers in Southern Africa run their operations successfully and their continuous expansion. With an ever

drier climate every year, the focus on water conservation and increasing yield by employing latest technologies, the Undercover Farming Expo & Conference 2020 once more offered a high level of exhibitor occupancy as well as a most interesting speaker portfolio.

Undercover Farming management received tremendous positive feedback and most exhibitors ordered their floor space for the next event before they left the premises.

The speakers share in-depth knowledge not only of the industry, but specifically about Southern Africa’s hydroponics industry’s progress at the 2020

“The event date for the 2021 Pretoria conference will be set for March in the near future and all role-players, farmers and input providers in the industry will be notified in due time. The Undercover Farming Expo 2020 was yet another successful event due to the participation of industry leaders and we thank all exhibitors, speakers, delegates, visitors and all involved to once more make this event successful!” concluded Suzanne. Further information on future conferences and exhibitions available from: Suzanne Oosthuizen, suzanne@axxess.co.za, Cell: 082 832 1604

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Conference 2020 - Pretoria

Conference Speakers that presented this year were:

• “Greenhouse Leasing Concept” Presented by Vaughan Coetzee - Model Capital

• “Clearing and Forwarding in 2020” Presented by Laura Dewar – GAC Laser

• “The role of regulation in agriculture” Presented by Zodwa Cibane & Francois Knowles – APAC

• “Characteristics of an efficient irrigation system” Presented by Isobel van der Stoep – Cherry Irrigation

• “Integrating bio-solutions with conventional chemistry” Presented by Jaco Marais – SABO

• “Soil health” Presented by Koos Coetzee – Shiman

• “Current world trend: Control of pest and diseases without chemical residue” Presented by Nico Uys – AgroOrganics

• “New innovation in Calcium nutrition” Presented by Gerrit Burger – Haifa

• “Organic waste management, Growing media amendments and Plant & pest disease control” Presented by Roger Jaques – UkuZwana Project Management Solutions

• “Herb Health & Essential oil – Growing Commercially” Presented by Dr Gail Pedra – The Herbal Counter

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Calcium nutrition is an important component in growing a plant to obtain optimum success. Nutrition by means of NPK is a combination of macro nutrients required to grow any crop.

Calcium & your plant – how it influences optimal production

Quality produce on a plant with well-balanced nutrients.

Most importantly, before planting valuable seed or plants, one must ensure that the pH is correct in a soilless medium or the soil itself. In the soil or medium, a pH of 5.5 to 6.5 offers an acceptable operating value in which a plant would flourish. Some nutrients cause antagonisms or synonyms; thus said, some nutrients function better along with other nutrients because the higher value in certain nutrient compositions will suppress other nutrients with a lower value. If, for instance the Calcium value is very high in the soil composition, it will suppress the functionality of the magnesium – which is an important nutrient as well. Similarly, if the ammonium level in the soil or medium is too high, it will also suppress the other nutrients in the combination of the medium. It is therefore important for the greenhouse operator to keep track of his nutrient combination in his growing medium or his soil.

Nitrogen is present for plant uptake in the ammonium form or the nitrate form

(NH 4 or NO 3

) but if ammonia levels are excessive, it suppresses the nitrate functioning. One needs the solutions offered to plants to be lower in ammonia in order to increase the uptake of calcium. Nitrates promote the uptake of calcium, magnesium and potassium. On the other hand, when the ammonia levels are higher in plants, it will suppress uptake of valuable food to the plant and inhibit growth. To obtain good, strong cell walls in a plant, calcium is required – it is the cement that bonds cell walls together and in so doing, ensure good quality fruit.

Calcium and nitrogen makes up about half of the fruit. Up to 28% of a healthy fruit contains nitrogen, 6% calcium although the latter plays a major role in the plants’ stem cell walls.

The plant with a well-balanced Calcium contents, is much less susceptible to diseases. Calcium-related disorders are often related to environmental conditions such as temperature, humidity, salinity; all conditions that does not favour the uptake of calcium. One may therefore feed the plant enough calcium during the fertilizing program, but its environmental conditions prohibit the uptake of calcium.

Another condition often experienced, is during hot, arid climate where transpiration is so fast, calcium cannot make it to the fruit in time and it appears calcium deficient.

Uptake of calcium is predominantly through the xylem towards the fruit.

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Therefore it is also important for excellent root establishment to take up calcium via the roots, the xylem to where it matters most; the fruit. In the case of excessive warm conditions the plants, transpiration is high, calcium travel upwards also decreases.

The translocation of calcium is difficult in adverse conditions. The plant requires calcium, which is transported in the nutrient solution from the soil or grow medium, and as explained, it reaches the leaves where it remains. When the fruit set appears, it takes up the nutrients also containing mobile nitrogen and phosphates from the surrounding leaves to grow bigger to harvesting stage. Nutrient solution values are adjusted by the producer to obtain best results for his ultimaterequirements.

Calcium at this stage plays a critical role as it increases in value in the leaf section of the plant. Extra calcium as part of the fertilizing program is given to the plant during fruiting although it is difficult for calcium to travel from the leaf into the fruit. The problem really lies within management – to ensure the flow of the correct nutrient recipe containing calcium to travel up the plant on a continuous basis and not only when fruit set is observed.

Not following this continuous program, the nutrients remain at the base of the plant and diseases like blossom-end rot (clearly visible in peppers and tomatoes)

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Calcium-related disorders are often related to environmental conditions such as temperature, humidity, salinity; all conditions that does not favour the uptake of calcium.

and the lack of nutrients and calcium id even visible at the end of plant stem or leaves. Especially in peppers; if the leaves around fruit set are wilted and yellowing, it is better to pick the fruit and discard it. In strawberries the stem goes dark and leaves wilt and fruit turns black – a sure sign of deficiency of nutrients. Even in celery, cabbage and fruit, lack of readily available calcium in the nutrients are too obvious, but too late to adjust to save the crop.

How to overcome these situations to take preventative or at least corrective action Since summertime comes with high temperatures, irrigation must be stepped up and nitrogen content ofnutrition increased. The management of any fresh produce or fruit production lies therein that records must be held of date, prevailing outside temperature, pH levels taken at different areas in the greenhouses, nutrition dosing recipes applied and quantity of fruit obtained per plant.

Also, in case of adverse situations, what the causes were, remedial stepstaken and dates thereof. In this way the producer builds up a personal history record on which he can reflect in times of crises but that his staff or eventual manager can use as a handy tool to ensure flow of production at even keel.

Since summertime comes with high temperatures, irrigation must be stepped up and nitrogen content of nutrition increased.

Separate tanks for nutrients In a typical greenhouse with automated dosing system one would find an A tank, holding nutrients (micro-nutrients; sulphur and phosphate for a hydroponics mix) without calcium, then the B tank holding Calcium and magnesium nitrate.

A new product used in Spain and the Netherlands is now launched in South Africa (enquire at your agro chemicals outlet). It is a more refined nitrogen calcium product that can be used in difficult conditions of calcium uptake. The calcium and nitrogen levels are increased and more concentrated although, the calcium is significantly higher concentrated than the nitrogen which offers the producer more management options. Ammonia level in the product is dropped from 1.3% to .3% to ensure enough calcium is released.

It is important that the pH does not acidify more; therefore the new product will rectify this. In zones with ultrahot temperature and high radiation, the plant takes up a lot of water and a solution with low ammonia is required. Once excessive ammonia is taken up by the plant, the amino acids in the leaves are required to neutralize the effect of the ammonia, but can only do so if the flow of water up the xylem is fast enough. The product is also moreconcentrated which means easier to handle and takes less storage space.

It is often observed that farmers have too much nitrogen in the system which appears as leaf yellowing. These plants are very lush but are more susceptible to plant diseases but the right product can correct this for the producer.

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Act 36 of 1947 – What does the law say about fertilizer?

In this editorial, Lindi Grobler of Agri-Alchemi outlines the do’s and don’ts of fertilizer application according to Act 36 of 1947.

‘We are all aware of the necessity to use only registered fertilizers, but what is this registration and why is this registration important to you as end user? What should you be aware of? Is the product you are using correctly registered according to the claims made on the label? All these questions are important to have answered not only for yourself but also for your GAP accreditation,” Lindi says.

Here are a few questions for you to ask and answer enabling you to evaluate the legitamacy of a registered a product and what it means to you.

What fertilizer should be registered under Act 36 of 1947? Act 36 of 1947 states that any product containing inorganic or organic fertilizer (including compost and growing medium) or products containing natural or synthetic inorganic, organic, living and non-living substances (or combinations of any of the above), should be registered. The content of the product determines the registration;

Group 1 – fertilizers containing a total equal or greater than 100 g.kg -1 of N, P, or K or any combination thereof; such as macro-nutrient straight or combination products.

Group 2 – fertilizer containing a total of less than 100 g.kg -1 of N, P or K or any combination thereof or any recognized plant nutrients in acceptable amount; such as micro and or only micronutrient straight or combination products

Group 3 – products containing natural and synthetic inorganic, organic and living substances promoting and improving growth or products colonizing the

rhizosphere or the interior of the plant; such as biofertilizers, plant stimulants, plant growth enhancers, and micro-organisms.

There is of course also the category of products protecting plants against pests and diseases, referred to as the L- registrations, not to be confused with the Group 3 products that only enhance or improve plant growth.

What must be displayed on the bag, bottle or drum I buy? According to Act 36 of 1947 all and any product manufactured and/or importerd should either have a registration number or exemption from registration issued by the Department of Agriculture, Forestry & Fisheries (DAFF). Once a product is registered;

• the registration number must be visibly and correctly displayed on the packaging,

• the product constituents must be visibly displayed in elemental form according to South African nomenclature,

• the registration holder contact detail and physical address must be given, and

• the batch number with date of manufacture (in relevant cases shelf life, as well) must also be displayed on all and every container sold, without exception.

There is provision for custom mixes (often referred to as prescription mixes) but only under limited and specific circumstances with several restrictions, rules, and regulations. At any given

Fertilizer, chemicals and related products should be stored neatly and locked-up.

time, documentation as to the reason for use of a custom mix in preference to a registered product, order for said custom mix from the client, volume manufactured, volume supplied, raw material used in the product, and registration of raw materials must be available to the client and DAFF inspector.

What does a registered product mean to the end user? The benefits to a client using a registered product from a reputable company are as follows:

• The product quality has been tested and approved by DAFF to be within allowable concentrations stated on the label.

• The product does not contain any heavy metals outside of the allowable concentrations harmful to plant production of human consumption ensuring the client using the product and the consumer is protected.

• Proof has been supplied as to the efficacy and non-phytotoxic nature of the product when being used or applied as per the label.

• An accredited MSDS (material safety data sheet) is available for your reference.

• Quality control is adhered to by the registration holding company to ensure the product remains, at all times within the specification registered.

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Aquaculture: Industry with great expectations

As the world population roared past 7.7 billion people, and as warnings of drought, heat waves and food shortages continue across the world, the aquaculture industry is quietly growing into a substantial producer of fish across the continent.

As the number of people

increases the allocation of precious basic resources is decreasing per person. We are therefore obliged to find more efficient ways of producing food that do not require massive quantities of land and water.

Recirculating water is the future of the industry as a small footprint is required, water usage is very efficient and huge quantities of fish can be produced from these installations. Importantly, going forward the dual advantages of excluding both pesticide pollution and fish diseases will be in favour of recirculating systems over ponds and cages.

Aquaponics is a further deal sweetener as a second crop can be produced cost effectively from the wastes generated by feeding fish. In terms of food security, environmental sensitivity and profitability, aquaponics is becoming a mainstay in the RAS sector of the aquaculture industry.

In recent months several installations were completed in multiple aquaculture,

Catfish & tilapia hatchery and fingerling system

Tilapia RAS inside a greenhouse

aquaponics and hatcheries for tilapia and catfish. On this page are some examples of these systems.

By: Leslie Ter Morshuizen

Ebb & flow aquaponics system inside a greenhouse

Hybrid aquaponics system inside an existing tunnel

Catfish RAS inside a greenhouse

Act 36 of 1947. 16

• Representative samples are kept of each batch manufactured or imported to prove even after supply, the product is accurate as per the registration.

• Any client has legal recourse in case of a claim about suspected irregularities in product quality, concentration, method of application, or application rate.

Read the product label. Check the packaging you are receiving from your supplier and communicate with your supplier as to any irregularity, omitted information, or oddity for immediate action. Mistakes can happen but it should be the exception rather than the norm, thus also giving credibility to your supplier. The onus to ensure products you use on your farm are registered is as much the responsibility of the client as it

is that of the supplier. References: Department of Agriculture, Forestry and Fisheries. Fertilizers, farm feeds, agricultural remedies and stock remedies act, 1947 (Act No. 36 of 1947). Issued in the Government Gazette, September 2012. 67 p.

Department of Agriculture, Forestry and Fisheries. Guidelines for registration of Group 3 Fertilizers (Act No. 36 of 1947). Issued by the Registrar, June 2019. 12 p.

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Novel equipment: Farmers urged to de-silt reservoirs before dry season

As the dry season approaches in many parts of South Africa, farmers need to ensure that silt is not limiting the volume of water that they can store.

The progressive build-up of silt

means that dams and rervoirs in the agricultural sector can steadily lose storage capacity. By the time the rainy season comes to an end, it is vital that farms have maximum capacity in their water storage facilities to see them through the dry months – that is why the dams and reservoirs need to be cleaned or de-silted now.

Cleaning excess silt from dams is sometimes attempted manually, but this solution is not only time consuming, it is very inefficient. There are companies that specialise in removing silt from storage and settlement dams and have developed fit-for-purpose equipment for this task.

This includes the SlurrySucker, which is mounted on a floating barge that is pulled back and forth across a dam. This innovative system has a dewatering pump that feeds surface water down to a dredge-head, agitating the silt using seven bar of pressure through 16 nozzles. A special slurry pump then pumps the agitated material out of the dam.

The solution also ensures there is no damage to the clay lining or geomembrane that lines most dams. To achieve this, hose floats are used to keep hoses and electrical cables on the water

surface, so they do not drag along the bottom of the dam and onto the lining. The system is simple enough for

before

AFTER

Before and after shots of desilted resevoirs.

farmers to use by themselves on a rental basis, while specialised on-site supervision and training can be provided.

Subscribe now! The subscription fee for six bi-monthly issues amounts to

R 265.00 (VAT & Postage included, S.A. only). Electronic subscription amounts to R190.00 annually. Foreign subscribers: R 420.00 per annum (VAT & Postage included).

Fill in this form, pay in your deposit and fax your deposit slip together with your details below to: Fax: 086 518 3430 Or you may post your cheque and this form to: Undercover Farming Subscriptions, P.O. Box 759, Montana Park 0159. 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

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Account Name: Nufarmer Pty Ltd t/a Undercover Farming Bank: First National Bank, Kolonnade Branch Code: 25 10 37 • Account No: 62007699806

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UCF Western Cape Conference

Remember this date!

7-8 October 2020

Contact Suzanne Oosthuizen 082 832 1604 Suzanne@axxess.co.za