Response of Selected Cabbage Varieties to Alternaria brassicicola underGreenhouse Conditions

Abstract

Dark leaf spot (Alternaria brassicicola) is an important disease of cabbage crop. It is a major constraint in cabbage production in Kenya causing substantial losses if not managed properly. Hybrid varieties are now in the market but there exists little information on their resistance and tolerance to this disease. To undertake breeding for resistance and come up with improved varieties, there is need to identify cabbage genotypes for possible sources of resistant genes to the disease. This study was carried out to assess the response cabbage varieties to Alternaria brassicicola pathogen at the University of Eldoret,School of Agriculture and Biotechnology Plant Pathology Laboratory and in the greenhouse. Isolation and purification of the pathogen was done in appropriate conditions in the laboratory and inoculated on to 10 days old transplanted seedlings. The experiment was laid as completely randomized design (CRD) with each variety replicated four times. Scores were made using a scale of 1-10 on nature of the leaf with leaf spots and percentage disease index per plant was calculated. Data collected was analyzed usingGenstat software version 14.1. The study revealed no significant difference in percentage infection among varieties. Using single link method three clusters were formed at 95% similarity coefficient axis. It was concluded that Gloria F1 and Copenhagen were susceptible; Queen F1 was tolerant while Pruktor F1 and Sugarloaf varieties were resistant. Breeding institutions and farmers are recommended to use tolerant varieties for breeding improvements and high yields