Differential Soil Acidity Tolerance of Dry Bean Genotypes.

Soil acidity is a major yield limiting factors for bean production in the tropical regions. Using soil acidity tolerant genotypes is an important strategy in improving bean yields and reducing cost of production. A greenhouse experiment was conducted with the objective of evaluating 20 dry bean genotypes for their tolerance to soil acidity constraints. Inceptisol soil was amended with dolomitic lime (6 g dolomitic lime kg^-1 soil) to achieve low and without lime  (zero lime kg^-1 soil) to achieve high acidity levels to evaluate bean genotypes. At both the acidity levels genotypes differed significantly in shoot dry weight and grain yield. Shoot dry weight and grain yield were significantly decreased at the high acidity level compared to low acidity level. Grain yield was more sensitive to soil acidity compared to shoot dry weight. Based on grain yield tolerance index, 55% genotypes were classified as tolerant, 40% were classified as moderately tolerant and remaining were grouped as susceptible to soil acidity. The genotype CNFC 10410 was most tolerant and genotype CNFP 10120 was most susceptible to soil acidity. Number of pods and grain harvest index were significantly and positively associated with grain yield. The improvement in grain yield may be related to neutralization of soil Al³⁺ and H⁺ ions toxicity by lime addition. At harvest soil extractable P and exchangeable K increased with the reduction of soil acidity.