Screening for host plant resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) in selected chickpea (Cicer arientinum L.) genotypes in Kenya

Abstract

Helicoverpa armigera is a major pest on the chickpea (Cicer arientinum) world. In Kenya, it causes up to 80% yield losses of the crop. Control measures include application of pesticides and cultural methods which have become less feasible due to their associated costs. Host plant resistance can offer long-term benefits in managing this pest. The objective of this study was to screen and identify chickpea genotypes that are tolerant to Helicoverpa armigera infestation under field conditions. Thirty chickpea genotypes were screened at Agricultural Training Centre, Koibatek under field conditions for two seasons in RCBD design in 3 replicates. Data on larval densities, percent pod damage, and amount of leaf consumed were transformed using angular transformation and then subjected to ANOVA, while treatment means separated using Duncan’s Multiple Range Test at P≤0.05. Correlation analysis between larval densities, yield and yield components was done using Genstat 12. The genotypes were classified into various categories of resistance and susceptibility on a visual leaf damage rating scale of 1-9. The results showed that there was significant variation in larval densities among the genotypes. At vegetative stage, mean larval densities ranged from 0.15 to 1.2 Genotypes EC583250 and EC583264 had lowest larval densities while ICC4973 and ICC3137 had highest densities. Larval densities increased from 0.3 to 1.97 during flowering stage. The larvae population increased drastically to a mean of 3.58 at podding. Genotype EC583260 had the least larval density of 2.2. The genotypes, EC583318, EC583250, EC583260 and EC583264 were least infested by the larvae with percent pod damage ranged from 3% on EC583264 with high yields while ICC3137 had highest pod damage of 20.2%. EC583260 was found to be low yielding (1051kg ha-1) while ICC4958 was the high yielding

Egerton J. Sci. & Technol. Volume 13: 39-55 ISSN No. 2073 - 8277

(2205kg ha-1). Genotypes EC58318, ICCV10, ICC14831, EC583260, EC583264, and EC583250 had high resistance and could be exploited to chickpea breeding programmes as source to resitance.