Pests are becoming notoriously more difficult to control in horticultural crops, showing increasing resistance to traditional, conventional chemistry. However, the introduction of macrobiologicals offers an additional tool for effective control strategies.
The latest (AMBER) project trial report, which shows significant reductions in Western Flower Thrips numbers in protected ornamentals using biopesticides as part of an integrated pest management (IPM) strategy, is positive news for the sector.
An immediate 79% decrease in thrips was achieved three days after a single tank mix application of Botanigard and Majestik in a programme with the introduction of macrobiologicals.
Importantly, 100% elimination of the pest was achieved by the end of the trial following a single application of Azatin.
Mode of action
Azatin works as an anti-feedant and insect growth regulator with a slow mode of action (MoA), which is best used before thrips appear and to prevent the pest coming back once populations are reduced.
Botanigard and Majestik work in harmony with differing MoAs, when used as an immediate response to seeing thrips on crops.
Whereas Botanigard works on contact, penetrating the skin and depleting nutrients from within the pest, Majestik slows down metabolism and breathing, increasing the likelihood of Botanigard infection.
In light of these trial results, Certis’ IPM Manager, Selchuk Kurtev, recommends an IPM approach to reducing thrips in protected ornamentals utilising biopesticides as a secondary line of defence.
1. Introduce macrobiologicals, such as predatory mites, in susceptible crops at the start of crop production, even if thrips are not seen
2. Monitor crops for thrips once a week, particularly at growing points, around flower buds and flowers
3. Apply Azatin at first sign of thrips to benefit from the anti-feedant effect and slow MoA
4. If required, apply a single dose of Botanigard and Majestik when thrips populations are starting to build up
5. In high risk periods when thrips are likely to increase, make a repeat application of Azatin to capture new generations. Additional applications can be made if required, five to seven days apart
The Application and Management of Biopesticides for Efficacy and Reliability (AMBER) project is funded by the AHDB and managed by Warwick Crop Centre to identify practical ways for growers to improve the performance of biopesticides in crop protection programmes.