Dry Bean Genotype Evaluation for Potassium-Use Efficiency

Abstract

Dry bean (Phaseolus vulgaris L.) is an important food legume for the South American population. In South America it is eaten every day by all sections of the population along with rice. The average yield of this legume is low in South America and use of inadequate rates of fertilizers, including potassium (K), is one of the main factors. A greenhouse experiment was conducted to evaluate thirty dry bean genotypes for K-use efficiency. The K rates used were 0 mg kg−1 (low) and 200 mg kg−1 (high). Soil used in the experiment was an Oxisol. There was a significant response of potassium level and genotypes for most of the growth, yield, and yield components. In addition, K × genotype interactions were also significant for most of the traits evaluated. The K × genotype significant interaction indicates different responses of dry bean genotypes to change in K levels. Based on grain yield efficiency index, genotypes were classified as efficient, moderately efficient, and inefficient in K-use efficiency. Grain yield showed a significant positive association with straw yield, number of pods per plant, number of grain per pod, root length, and grain harvest index. Overall, maximum grain yield was obtained with Mehlich 1–extractable 76 mg K kg−1 soil and K saturation of 3.2 percent.