Colonization of Tomato Varieties by Beauveria bassiana Isolates in the Screen House

Tomato, Lycopersicon esculentum Mill. (Solanales Solanaceae), is a major vegetable crop cultivated worldwide. Production has increased over the years, in most parts of the world, however decline in yields in Kenya has been due to environmental stresses, declining soil fertility, poor crop management and low quality seeds. Pest and disease pressure has also increased, reducing the yields. Chemical control has been widely used over the years but cases of resistance have developed. There is need to seek alternative measures such as biological control agents to complement existing measures. Beauveria bassiana has been known to control insects pests, diseases and also establish as an endophyte in a variety of plant species. Five isolates IC 283, IC 279, IC 273, IC 10 and IC 35 were tested using seed inoculation in the screen house to establish their endophytic association in three tomato varieties Cal J, Kilele and Anna. Beauveria bassiana isolate IC 35 was able to colonize between 3 to 6 % of leaves, stems and roots of the three tomato varieties. All the other four isolates were undetectable in all three plant parts of the varieties tested confirming no colonization.