The effect of the relative planting time of the consorcium corn x cowpea on the presence of useful insects and the economic management of pests

Abstract

An experiment was carried out in 1983 at the Estação Experimental do Vale do Curu, located at Pentecoste, CE, Brazil, in order to study the effect of relative planting times of intercropped cowpea x corn, and as single crop, and their reflexes on the aspects of populational dynamic of key--pests, during the critical periods of those crops, taking in to consideration their economic control levels and the behavior of the natural enemies of the pests in relation to their occurrence. The results indicated that in the corn x cowpea consorcium the nymph of Empoasca kraemeri population is reduced, when compared with occurrence in the cowpea as single crop, while the use of insecticide to control Chalcodermus bimaculatus was successful on an economical basis, reducing the incidence of the pest attack and amount of damage in cowpea. Field inspections must begin when the first pods appear. On the other hand, the phases 1 and 2 of corn were confirmed as critical to the attack of Spodoptera frugiperda.