Zero-residue fresh produce a reality

Retail giants are calling for caution when using biologicals and chemical pesticides, writes Lindi Botha.

Push-back on chemicals for crop protection is increasing from legislators, consumers and supermarkets. Although the range of biological products to use instead is expanding rapidly, farmers still lack the knowledge and confidence to use them, while regulators are holding back progress on more advancements.

At a Woolworths suppliers’ day held in Mbombela, Mpumalanga, in April, the supermarket group outlined its goal to have all fresh produce attain a zeroresidue status by 2035. This requires a more considered use of crop protection than the current system of maximum residue levels (MRLs), where products can still leave residues as long as they are within prescribed amounts.

Kobus Pienaar, Woolworths’ technical manager for food security, emphasised that the supermarket was not advocating for zero-pesticide use, just that greater emphasis should be placed on using biologicals, and where chemical pesticides were used, it needed to be done early enough in the season so as not to leave any residues.

“We want to address chronic low exposure to chemicals because it does have adverse effects over the long term – on farm workers’ health, that of the consumers and the farming environment,” said Pienaar.

A system focusing on biological pest control requires a far greater understanding of pest cycles on the farm. Pienaar said that farmers would need to gain greater insight into breeding cycles, periods when pests were most vulnerable, and which biological products would be most affective for those specific periods.

“We need to stop routine use of pesticides, like spraying on a certain day of the week, regardless of whether there is pest pressure or not,” he said.

Karlien Muller, managing director of Auxano Tissue Culture, told farmers that biological crop protection meant that every season a new plan needed to be developed to deal with pests.

“Biologicals and chemicals need to be able to fit in together like puzzle pieces to make up the whole picture. Each season you will need to figure out what will be needed when to ensure your picture translates to environmental benefits, food that is safe for customers, and products that can still be used next season since no resistance build-up in pests has been enabled,” she said.

While the range of biological products on the market has grown tremendously over the past few years, stakeholders are concerned about the slow pace of product registration in South Africa, which had curbed further advancement.

Speaking about the ability of the current biological offering to protect crops, Pienaar said that more products were still needed to address all the problems. “But if chemicals are used responsibly, and well timed, they can be used in conjunction with the available biologicals to provide protection and a zero-residue measurement.”

Of concern, however, was that farmers were reluctant to try new production techniques when their incomes were at stake. Pienaar said that experimental farms were needed where farmers could see first hand how products should be used and their success rates. He noted that there was also a lack of awareness about how robust current biological solutions were, since farmers often relied on input suppliers for information, and many were still focused on chemicals.

‘WE WANT TO ADDRESS CHRONIC LOW EXPOSURE TO CHEMICALS BECAUSE IT HAS ADVERSE EFFECTS OVER THE LONG TERM’

LINDI BOTHA Using biological crop protection requires a greater focus on cultivating environments where beneficial insects can thrive, like planting additional host plants.