Screening chickpea (cicer arietinum l.) genotypes for fusarium wilt resistance and its management using fungicides, in Njoro Kenya

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris is a seed and soil borne disease affecting chickpea, Cicer arietinum L. It is widely distributed where chickpea is grown causing yield losses ranging from 12 to 100% depending on the level of resistance of the genotype and the suitability of environmental conditions for disease development. Evolution of new and virulent races of Fusarium oxysporum f. sp. ciceris necessitates continued screening, breeding and deployment of new resistance genes when hitherto resistance genes succumb to new races of the pathogen. Two experiments were set up in this study. The aim of the first experiment was to screen 20 chickpea genotypes introduced from ICRISAT for resistance to Fusarium wilt under greenhouse conditions in a completely randomized design (CRD). The second experiment was conducted to evaluate efficacy of two fungicides, thiram and carbendazim in managing Fusarium wilt and was in a split plot design. Four rates of each fungicide (0%, 50%, 100% and 150%) of the recommended rate (1.5 g/Kg seed), were used. One resistant variety (Chania 1) and one highly susceptible variety (Chania 2) selected from the greenhouse screening experiment were used in the field experiment. Six genotypes were found to be moderately resistant, ten were susceptible and four were highly susceptible. Carbendazim and thiram rates were effective in reducing wilt incidence in chickpea. The least wilt incidence was observed when 150% rate of either thiram or carbendazim was used. Highest wilt incidence was observed in control treatment plots. There was a positive interaction between variety and fungicide application on dry matter and grain yield. Interaction between moderately resistant Chania 1 and fungicide resulted in significantly lower wilt incidence, higher dry matter production and highest grain yield of 1.4 t/ha. Significantly higher wilt incidence, lower dry matter and grain yield of 1.3 t/ha were observed in the interaction between fungicide treatment and highly susceptible Chania 2 variety. Six moderately resistant varieties; 95423, 97105, 97114, 97125, 97126 and 97406 could be used together with 100% and 150% rate of application of either thiram or carbendazim in order to manage wilt incidence and ensure higher dry matter and grain yield