Major differences in thrips pressure between fields

What influence do factors such as cultivation method and plot location have on the development of onion and bean flies and thrips in seed onion cultivation? In 2020, a start was made at 10 locations in Flevoland and Zeeland to find an answer to this question through monitoring.

In various cultivation systems, leeway effects, various strip widths, neighboring crops, variety (type), organic or conventional cultivation were examined.
Only limited statements are possible on the basis of one year of monitoring. The variation in the thrips population between fields was significant, both between organically and conventionally grown onions. At the moment, the figures show no difference in numbers of thrips in the crop close to or further from the field edge. There do appear to be differences in thrips pressure between neighboring onion crops, although the relationships are not yet strong. The monitoring program will be continued in 2021 in order to arrive at further insights and conclusions.

Click here for the interim report of the 2020 trial year. 

Resources for thrips research 2021: adjustments to spray moment and technique
Various low-risk resources will be used up in 2020 Tabaci Thrips tested in onion in Tollebeek, Wieringerwerf and Colijnsplaat. The starting moment of the treatments is determined with the help of sticky traps. The assessments only looked at the larvae of the thrips.
All treatments in the trial showed an effect compared to untreated, with the control effect of chemical agents being the greatest. Although the effect was less significant, a clear effect was also observed of green products.

Improving the effectiveness of green resources is one of the spearheads in the follow-up study in 2021. An attempt is made to achieve the improvement by adjusting the spraying moment and the spraying technique and making combinations.

Download the full report on trial year 2020.

This article is from Ureka† Uireka is a unique chain project, where Hazera participates in. Its aim is to improve the quality and thereby strengthen the export position of the Dutch onion.