“Ah, there goes a butterfly. That’s a good sign,” says André du Toit, general manager of Kleinberg Kriegler Farms in De Doorns in the Western Cape. He is standing between his vines where table grapes are produced using an integrated pest management (IPM) programme.

This relies on synthetic chemicals for crop protection early in the season, moving to biological products later to ensure the produce meets maximum residue level (MRL) regulations and to reduce the negative impact of the former on the ecosystem.

The presence of insects like bees and butterflies bodes well for the farm – it indicates that pesticide levels are in check, rather than being so abundant nothing can survive. Achieving this balance between pests and beneficial insects is, however, no mean feat, but one that is certainly becoming easier to pull off.

“The developments taking place regarding biological pest control have been really exciting,” says Du Toit. “We’re able to achieve 100% control of mealybug using an IPM programme, which means we meet MRL regulations while nurturing the natural resources of the farm.

“At the start of the season, we use a systemic insecticide to get a knockdown effect on mealybug. Once fruit is nearing harvest, we send in parasitic wasps, which takes care of any remaining mealybugs but obviously does not result in a chemical residue on the fruit. Considering that mealybug can wipe out 30% of your yield, it’s a huge advantage to have effective, robust tools like these,” he explains.

Kleinberg Kriegler has been using biologicals since 2000. Du Toit notes the progress in the industry: “Ten years ago, around 40% of our crop protection a month before harvest would have been biological. Today, it is just over 80%.”

The right approach

Such success bodes well for the industry. With increasing pressure to reduce the use of synthetic chemicals on food crops, farmers are being pushed to adopt biological pest control to retain market access.

Kleinberg Kriegler delivers table grapes to export and local markets via Woolworths.
The latter recently announced a target of having all of its fresh produce meet a zero-residue level by 2030.

Not leaving it to chance, the retailer has embarked on an education campaign to help farmers better understand how biologicals work and link them with reputable suppliers and advisers who can aid them in their journeys.

Woolworths is the first retailer to join the South African Bioproducts Organisation (SABO), creating a powerful network to help farmers succeed.

Kobus Pienaar, technical manager for food security at Woolworths, says the biggest challenge in getting more farmers to adopt biological crop protection is the lack of knowledge about how to use these products.

“South Africa has a good selection of biological alternatives to synthetic chemicals, but farmers don’t always know how to use them for optimum success. This is why we initiated the information days, linking farmers with experts in the biological crop-protection industry.

“Since there is no one-size-fits-all approach to IPM, we use these networks to create tailor-made cultivation programmes for farmers that take their farm’s unique circumstances into account, creating a culture where farmers manage their farms as ecosystems and not as factories,” he says.

Pienaar notes another issue in gaining greater conversion: the fear of failure. “The last thing anybody wants is a reduction in output when biological control is implemented. So, if farmers aren’t convinced that the products will work, the chances of using them are diminished.”

This is where SABO plays an important role; it brings together suppliers, distributors and retailers to provide support, training and regulatory guidance to ensure products deliver on their promises.

Alison Levesley, general manager of SABO, notes that growers and distributors need to have reliable access to biological and alternative solutions to effectively implement IPM programmes.

An ethical system

“Before products are registered, they have to go through trials to ensure they are safe and effective, as well as reliably produced, which is evaluated [by the Department of Agriculture]. Registrations therefore provide peace of mind for farmers, and using anything other than a registered product, according to the label requirements, is extremely risky and contrary to the requirements of the regulatory framework.”

All agricultural remedies registered in South Africa will have a registration number that starts with an ‘L’. Biostimulants have registration numbers that start with an ‘M’.

Companies that are members of SABO have a further obligation to ensure regulatory compliance, since SABO requires that member companies agree to a strict code of ethical conduct. This is an internal system set out to enhance the credibility of the industry.

Due diligence, however, does not stop with registrations. Debbie Matteucci, an independent regulatory and product development specialist and chair of the SABO board, explains that label information is very specific about how the product must be used and stored and what it can be used for. Deviations from label specifications can result in inefficacy.

Daunting at first

With biologicals requiring far more knowledge about pest cycles to accurately introduce them onto farms, an IPM programme can be daunting to take on.

“Biological products are not the same as synthetic chemicals. Very few have a knockdown effect, and it scares a lot of growers that effects are only seen later in the season or over successive growing seasons,” explains Matteucci.

“When using biologicals, you also need to consider what is happening in field: for example, mating disruption needs to be applied at a certain time in the pest’s life cycle to be effective, or it will only achieve low levels of success. The spray programme therefore needs to be well designed, as farmers need to understand the crop, weather and pest.”

Does this mean farmers need to have academic degrees in entomology to employ IPM? “No,” says André Labuschagne, campaign lead at Syngenta and board member at SABO. “All reputable crop advisers are well trained and have all the knowledge to help farmers choose the right products and apply them successfully.”

Emphasising the importance of using only registered products, Labuschagne adds that the product labels contain detailed information on how to use them, empowering the grower with the ability to manage their on-farm pest management.

A balancing act

Woolworths and SABO are quick to point out that the ultimate goal is an IPM that combines synthetic chemicals during high-risk periods and biologicals at other times, or just before harvest to achieve marketable fruit with zero residues.

Matteucci says that one of the biggest challenges in attaining a greater uptake of biologicals has been helping farmers understand that IPM does not mean that only biologicals can be used. “Synthetic pesticides still have a valuable role to play in ensuring food security and protecting yield during unpredictable outbreaks and weather extremes.

There may still be situations where you need them to get a knockdown effect to achieve a commercially viable yield. What’s important is being able to balance them with biologicals, crop nutrition, cultural management and soil health for a holistic strategy.”

Pienaar explains that Woolworths’ shift to zero residues is about addressing chronic low exposure to chemicals.

“Chemicals have adverse effects over the long term – on the health of farmworkers, consumers and the farming environment. But we still need to maintain production levels for food security. I believe an IPM programme that maximises biologicals can achieve this,” he says.

However, a mind shift is needed among farmers and consumers to balance insects and diseases on farms. Pienaar says that a lot of work still needs to be done to understand how to achieve the optimum balance between beneficial insects and pests.

“Biopesticides do not eradicate 100% of the pests, and farmers need to individually determine economic thresholds for their farm. This could mean allowing a certain amount of insect damage to maintain MRL thresholds, rather than applying pesticides to achieve 100% control, but leaving residues on produce.”

Labuschagne adds that insect damage is a bigger challenge for consumers than farmers. “Consumers want cosmetically perfect fruit, and to achieve this economically and sustainably without conventional crop protection is very difficult. Until consumers accept that a small blemish does not affect the quality and nutrition of the fruit, it will be difficult for farmers to market this fruit.”

The pressure on farmers to reduce MRL levels, however, leaves them with little choice. But as Du Toit relates, the advances in biological remedies is making zero-residue produce a reality.

“The benefit of beneficial insects is unmistakeable. But once they are in the orchards, using synthetic chemicals is out, or I’ll end up killing the beneficial insects. It can cost around R2 500 to R4 000 to populate a hectare with beneficial insects – there’s no way I’m wasting that by going in with a pesticide. So, in a sense, the biologicals also keep you honest because there’s no room for a safety-net chemical application.”

Problem-solving skills required

Successful IPM requires robust problem-solving skills, often looking beyond spray applications. To get optimum protection against botrytis on the grapes, Du Toit uses a combination of biologicals and paper bags that cover each bunch of grapes.

“Botrytis is a fungus that adapts very quickly, which means that a spray application that was useful today may be useless tomorrow. Since it’s prevalent close to harvest, chemicals are not an option lest the MRLs skyrocket.

“We use Bacillus and Trichoderma to keep the botrytis under control, which is really successful and results in a longer shelf life. But changing weather patterns have brought more incidents of unseasonal rain – causing botrytis to flare up. Now we apply the biologicals and immediately close the bunches with bags. This keeps insects away, but also keeps the bunches dry,” he says.

Pienaar believes that finding the balance between synthetic and biological crop protection will require more farmers to do trials to see first hand what works.

While farmers like Du Toit do their own trials, he notes that progress would be far quicker if everyone in a region worked together.

“We take one block at a time, do full biological control to see what works, and then take what does and see how we can fit it into an IPM programme. If every farmer in the region did this, we could learn from each other, taking advice from those who have similar climates and challenges and add to the collective knowledge.”

Advice for farmers

For farmers just starting out on this journey, Du Toit advises that they seek expert advice. This includes farmers who have had success, as well as product agents.

“Agents get around to a lot of farms and they have a front row seat into what works.”

He echoes SABO’s warning against using unregistered products. “The table grape industry has had a few difficult years and we are in a precarious position. We can’t afford to make any mistakes now that will risk our crop, or our residue levels. We’ve learnt to stay away from people peddling remedies that are not registered.”

In the meantime, SABO is working to improve the regulatory environment to ensure product registrations can get products to the growers quicker. This includes establishing working groups to create better guidelines for the registration process.

Matteucci says that the August 2023 publication of the updated Regulations Relating to Agricultural Remedies in the Government Gazette provides a major step forward for the industry, as it allows low hazardous products, such as micro-organism-based agricultural remedies to be fast-tracked for evaluation.

“The challenge the Registrar has faced is that there are many unknowns in how to evaluate and register the products, since they work differently to traditional chemicals. This is currently a global issue that regulatory bodies are experiencing with some over-regulating and others under-regulating, making it challenging to mitigate the impact of the phasing out of hazardous pesticides. The working groups are critical for ensuring our local registration process is streamlined,” she says.

Du Toit is optimistic about the future of grape production. “It’s been an amazing journey to see the growth of the biologicals industry. We have drastically reduced our chemical footprint, yet get even better pest protection than before. Biologicals have given us a holistic approach to crop protection,” he says.

Email the South African Bioproducts Organisation at [email protected].