Response of improved common bean (Phaseolus vulgarias L.) varieties to intermittent drought

Abstract

Objective: To evaluate 16 improved bean varieties for their response to intermittent drought.

Design/methodology/approach: A randomized design of complete blocks was used with four replicates under irrigation and four under drought condition. The drought treatment consisted of suspending irrigation for 15 days during the flowering stage, and the irrigation one consisted of maintaining available soil water above 60 % throughout the cycle. Yield and its components and days to physiological maturity were recorded, and the drought tolerance of each variety was estimated by using the drought susceptibility index, geometric mean and productive mean.

Results: Drought reduced yield 36 %, number of pods per plant 28.5 %, days  to physiological maturity 0.7 %, weight of 100 seeds increased 4.9 %, and seeds per pod was not affected. Flor de Mayo Eugenia and Negro 8025 showed greater tolerance to drought (p ≤ 0.05) than the rest of the varieties, with yields in irrigation of 2768 and 2854 kg ha^-1 and in drought of 1905 and 1843 kg ha^-1, respectively.

Limitations on study/implications: Limitations on study/implications: The drought intensity applied was relatively low, which could have made the differences between treatments less visible.

Findings/conclusions: Pods per plant was the most sensitive secondary attribute to intermittent drought, and the most drought tolerant varieties were Flor de Mayo Eugenia and Negro 8025.