Euschistus heros infestation levels in genotypes with insect resistance characteristics: productivity parameters and tolerance indicators

ABSTRACT

To be accepted as an alternative for farmers, new cultivars must have high productivity combined with characteristics of resistance to insects and diseases, which makes the selection process more difficult and complicated. This paper presents the results of a study conducted in 2020 in Londrina (Parana, Brazil) to evaluate the resistance/tolerance by submitting all genotypes to the same environmental conditions and subject to damage from the same number of bugs per cage, establishing different levels of E. heros infestation in soyabean plants, to subsequently evaluate their productivity indices and resistance/tolerance indicators. The present work aimed to test four levels of infestation in cultivars with the Block technology, and in promising lines developed by the Embrapa Soja breeding program for resistance/tolerance to E. heros, in addition to cultivar BRS 399 RR already on the market, as a standard for productivity and cycle. At the same time, the experiments were carried out to also test the hypothesis that tolerant and/or resistant genotypes abort a smaller number of pods and/or replace a large amount of fallen pods as a consequence of the damage caused by the insect. As part of the harvest was carried out in the days preceding the period of social isolation, as a result of COVID-19, the post-harvest analyzes planned for the laboratory are still being carried out on a rotating basis. Thus, there was not enough time to process the samples collected and the data obtained, as well as to carry out the predicted correlations and presentation of results.