Relationship between Leaf Water Status and Varietal Adaptation of Beans to Wet and Dry Agricultural Zones of Kenya

Abstract

Beans (Phaseolus vulgaris L.) are not native to Kenya (Purseglove, 1974) but a broad varietal diversity exists within the country. Also, even though only a few varieties have been developed and recommended for cultivation in various national agro-ecozones, there is a clear geographical partitioning of local land races which appears to restrict their ecological distribution. For example, Mwezi-Moja colour-type is the only readily available improved variety recommended for dry land areas, yet there are several land race varieties for which cultivation is restricted to low rainfall areas. Similarly, a number of other land races are cultivated only in high rainfall areas of the country. Such geographic distribution suggests differences in drought adaptation even among these undeveloped varieties since beans in Kenya are largely produced under rain fed conditions by low input small-scale fanners.