Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

New prospects for the protection of cowpea crops in Chad.

Abstract

The major pests of cowpeas in Chad are listed as Aphis craccivora, Maruca testulalis [M. vitrata], Megalurothrips sjostedti, Anoplocnemis curvipes, Mirperus jaculus and Clavigralla spp. The results are presented of a number of laboratory and field studies in 1989-91 on their control, including screening insecticides, reducing dosages, varietal susceptibility and application techniques. Control measures were shown to be necessary if cowpea culture is to be increased and effective. Bifenthrin, cypermethrin and thiodicarb appeared to be the best insecticides tested. Dosages used on cotton were shown to be unsuitable for cowpeas, and with bifenthrin and cypermethrin these could be reduced to one-quarter to three-quarters of those recommended for cotton. Dilution of the active ingredients to provide treatment at 10 litres/ha was shown to be advantageous. Important interactions between cowpea varieties and control measures were observed. Bifenthrin could be applied at 7.5 g/ha (one-quarter of the recognized dose on cotton).