Parameters to detect resistance of bean plants to Diabrotica speciosa, Cerotoma and Empoasca kraemeri

Abstract

This paper deals with the damage evaluation of Diabrotica speciosa, Cerotoma sp. (Coleoptera, Chrysomelidae) and Empoasca sp. (Homoptera, Cicadellidae) on bean plants (Phaseolus vulgaris). The parameters nr. of pods/plant and nr. of seeds/pod are more sensible than the parameters mean weight of 100 seeds and productivity, when the evaluation is done in times of pronounced variations in temperature and humidity. During periods of climatic instability it is not possible to compare resistance among bean cultivars, when one utilizes the parameters mean weight of 100 seeds and productivity, because the cultivars show the same behaviours when analysed by each one of these components.