Biobest informs pepper growers: new developments with degenerans

In protected pepper crops, growers tend to introduce a broad array of beneficials, in different combinations. Biobest Nederland recently organized two workshops in order to provide growers with up to date and complete information. The workshops were held on October 15 and December 10, 2014 in the Biobest offices in De Lier. The predatory mite A. degenerans received quite a bit of attention.

Irene van Schie, technical advisor at Biobest Nederland, started with an overview: of the beneficial insects and mites that are typically used in pepper. She covered different introduction strategies and discussed their pro’s and con’s. “Growers must take into account different factors”, says Irene. “There can be differences between pepper varieties. Some predatory mites are highly mobile while others remain near the release spot. Differences in sensitivity to pesticides need to be taken into account. And certain beneficials are not compatible because one species may predate on the other.”    
The workshops also included a practical session. Participants looked for predatory mites on the sweet pepper leaves in order to prepare them for identification. They could see how several species of the Amblyseius-genus cannot be distinguished with a magnifying lens, identification being possible only under a microscope.

“Hence when different predatory mites are released, it is usually difficult to prove which species has developed during the year,” says Juliette Pijnakker, R&D-employee of Biobest Nederland. “After consultation with their Biobest advisor – growers can deliver samples to our R&D department for identification.”

The discussion confirmed the large diversity of biocontrol strategies used by growers. Several growers indicated that the information received would help them rethink their strategy.    
“Our information about A. Degenerans was very positively received. Degenerans develops slowly during the first months of the year, but afterwards, the population explodes. We recommend it in particular in combination with A. cucumeris breeding sachets, with which it does not enter into competition. The cucumeris is especially effective during the first 3 months of the crop, while degenerans is most effective later in the season. It is the perfect combination against thrips. An additional benefit is that degenerans attacks spider mite during summer and autumn. In case there is a need for an additional thrips predator during summer, the grower can introduce the bug Orius laevigatus.”

Biobest further presented a new tool to better coordinate the peak periods of cucumeris and degenerans. Feeding of degenerans with Nutrimite™ (a special food supplement for predatory mites) substantially accelerates the development of degenerans. This strategy is now being tested in several greenhouses. “I received a lot of positive reactions to our workshops. Some growers even invited us to come to their greenhouses in order to implement Nutrimite™.” Concludes Irene.