Contribution of Seed Quality to the Occurrence of Fungal and Bacterial Diseases of Farmer Produced Common Bean in Varied Agro-Climatic Zones of Western Kenya

Abstract

Abstract: Farmers often recycle farm saved bean seeds from previous harvest for planting in subsequent cropping seasons resulting in reduced quality and buildup of seed borne diseases. This study investigated the quality of bean seeds in western Kenya. Bean seeds saved by farmers for planting were collected from 110 farmers. The seed samples were subjected to quality analysis including physical purity, germination and contamination with seed borne pathogens. The bean seeds collected comprised of 13 different varieties with Rose coco (23%) and KK8 (22%) being the most popular. The purity of seeds was about 76% which is below the recommended purity standard of 95%. However, the seeds met the minimum germination standard of 80% although 12% of the seeds were discolored and shriveled. Seed samples from farmers participating in upscaling technologies had significantly (p ≤ 0.05) lower contamination with Pseudomonas savastanoi p.v. phaseolicola at 747 CFU/seed compared to 1241 CFU/seed for samples from non-participating farmers. Fusarium solani was the most common fungal pathogen contaminating almost all the seed samples. However, there were no significant differences in the level of seed infection with fungal pathogens. The results indicated that recycling of bean seeds from previous cropping seasons contributes to reduced physical, physiological and health quality of the seeds. This has a direct effect in terms of reduced crop establishment, high incidence of diseases and low productivity in the subsequent season. Therefore, there is need to create awareness among farmers on good agronomic practices and on use of disease-free seeds.