New okra germplasm for the management of aphids in the diverse ecological landscape of Central Africa

Abstract

Ten okra accessions reported as resistant to aphids were compared in four agro-ecological zones of Cameroon with local varieties used by farmers under field conditions. This study was carried out over two seasons (March - July and September - December 2014) in four locations, representing four Cameroon agro-ecologies. The essence was to evaluate yield performance and test resistance to Aphis gossypii under different agro-ecologies. Aphid populations and yield parameters were evaluated. The R software package metan was activated to do analysis of stability using the multiple environment data. For all data, Breeding Values were predicted using Linear mixed model by performing best linear unbiased prediction on each genotype and for genotype by location interactions. The area under infestation pressure curve was calculated using aphid count data and the values used to estimate mean and standard deviation, and subjected to resistance analysis. For aphid abundance the lowest breeding value (-2.20) was for the Local and the highest (+ 2.33) for the most susceptible improved genotype. Two of the genotypes, Local (the most susceptible) and VI060794 (one of the moderately resistant) had the highest yield prediction per hectare and pods per plant. Dissemination of high-yielding and aphid resistant genotypes such as VI060794 stands the change of alleviating poverty and nutrient security within the sub region of Central Africa through reduction in cost of production from use of pesticide. The superior performance of VI060794 across ecological zones could be integrated in IPM of aphids and breeding to improve the performance of local germplasms.