Pepper growers in southern Spain faced a collapse in the lucrative markets of northern Europe when pesticide residue testing in Germany reported traces of the illegal insecticide isofenphos-methyl in 60 per cent of sweet peppers from the Almería region of Andalusia in December 2006.
However, in just a single season, testing has shown growers have eliminated the issue and restored confidence in their produce. In reality, by acting as the trigger to adopt the wide-scale use of biological control techniques, growers have earned the region a reputation for outstanding quality peppers with excellent environmental credentials.
The most recent report from CVUA, the Stuttgart-based pesticide monitoring centre, revealed no traces of isofenphos-methyl and no samples with residues of any pesticides above the MRL in the nine months to January this year. In fact, the average level of residues in the Spanish sweet peppers analysed was reduced by a factor of six compared to the previous season, and the number of active substances identified even at low levels reduced by a factor of three.
The 2006 CVUA report highlighted that German consumer reaction to the isofenphos-methyl scandal had seen demand for Spanish peppers plummet. Authorities seized and destroyed more than 100,000kg of peppers from growers, who also faced prosecution for their activities. Further testing by the CVUA revealed no traces of isofenphos-methyl in sweet peppers from the Netherlands, Morocco or Turkey, and growers in those countries were quick to seize the opportunity in the market.
Syngenta Bioline manager Melvyn Fidgett reports that, in response, more than 90 per cent of Almería’s pepper production has converted to the use of biologicals to control in-crop pests, combined with existing chemical control techniques. “Fortunately for growers, the timing of the Spanish sweet pepper crisis coincided with the introduction of a new predatory mite, Swirskiline (Amblyseuis swirskii),” he says. This new beneficial mite provides high levels of control of troublesome whiteflies and thrips in peppers, as well as other protected crops, including cucumbers and aubergines.
Fidgett recalls that the high intensification of production systems in Almería had resulted in almost uncontrollable pest levels and pests showing increasing natural resistance to approved insecticides, which had seen some desperate growers revert to illegal options. “Some growers were aware of the potential for biologicals, and had heard of the success achieved by growers in Murcia where the technique has been widely adopted, but the launch of Swirskiline gave them confidence in the potential for the solution,” he says.
At the same time, Syngenta Bioline introduced a major integrated crop management (ICM) training initiative for technicians and advisors.
The change has seen the ICM approach, previously adopted on fewer than 1,000 hectares of Andalusia’s protected vegetable crop in 2006, grow to more than 7,000ha in 2007.
“Crop monitoring to assess pest levels and the performance of biologicals is fundamental to their success,” says Manuel Gómez Romero, Syngenta ICM technical advisor for Almería. “Within six months, more than 90 technicians were trained to support growers in their daily decisions on when to introduce biological controls, and what further actions may be required to manage pest populations within the crop at commercially acceptable levels.”
With an effective biological control programme in place, Gómez calculates that growers can justify investing in newer chemistry that may be more expensive, but will have better results. He highlights the fact that new insecticides, such as Actara (thiamethoxam), have significantly lower environmental impact quotient (EIQ) rating than many older insecticides.
Seed treatment can remain an important chemical control technique to use in conjunction with biologicals, advises Gómez. “The use of biologicals to control foliar pests can minimise the need for repeated chemical applications and significantly reduce the risk of insects developing resistance, thereby maintaining the maximum efficacy of the chemical actives for the future,” he adds.
Dalias pepper grower Antonio Zamora had been pioneering ICM techniques in his protected crops since 2001, but reported varying degrees of success, sometimes experiencing less than acceptable levels of control. “I had serious problems with controlling whitefly and thrips, but also with caterpillars and mites as well,” he says.
“Since working with Syngenta Bioline, we have been able to devise ICM programmes better suited to my area, the crops we grow and my production system. We have achieved a noticeable improvement in the level of control we can achieve for all pests,” he reports.
“We do have to manage the crop more intensively in the way that we monitor for pests and pay close attention to any changes, but that does allow us to use pesticides less intensively; only spraying when and where we need to.”
Zamora has welcomed new techniques developed to quickly and effectively introduce biologicals into protected crop areas, including blister packs and water resistant sachets that can be simply hung on support wires without interfering with irrigation systems. “We are managing crops at different production stages across a large area, so need to have options that are quick and easy to use, but which will prove reliable. Our experience is that biological control can help us to achieve that.”
Although the success is a testament to the potential for biologicals, Fidgett remains cautious that growers see the technique as a simple panacea for every season. “Growers cannot afford to be complacent. Last year was a fantastic achievement, but 2008 will be a different season, with new pest pressures. They will face new challenges in the patterns of pest development, and will need to be ready to adapt the techniques used to match the threat,” he warns.
“If the ICM programmes that have proven so successful start to fail because of poor crop monitoring and decision making, growers could lose faith in the technique. The danger is that they may be tempted back into old habits. We are confident that if growers heed the advice given and continue to embrace the ICM principles, they can continue to manage pests effectively and deliver crops with lower levels of pesticide residues proven by Almería’s pepper growers.”
Following on from the success of biological control in sweet peppers, Fidgett says growers’ aspirations are that the ICM approach can be further developed from existing levels in other crops, including melons, cucumbers and aubergines.
“We are increasingly looking to work more closely with retailers and the food chain, to identify potential problems earlier and to come up with solutions that will meet with their own consumers’ demands, as well as being economically viable and practicable for growers,” he says.
He highlights tomato crops as being a particular challenge for the development of biological pest control solutions, since the role of bumblebees for pollination in the crop influences the choice of pesticide treatments. “The biological products available have not been so effective, and the level of satisfaction among growers not so positive. We will continue to work to identify better biological options.”
Fidgett expects that, over the coming years, many crops across the Mediterranean region will be grown using biological products as part of the pest control programme. “For this to be possible, new predators that can thrive in the local environment will have to be identified and developed, along with the commercial production systems to make them work effectively,” he adds.
No comments yet