Flooding influences on growth and development of bush bean under greenhouse conditions

Crop production in humid climates is often limited by severe thunderstorms that may leave soil flooded or waterlogged for several days. In 2001, a greenhouse study was initiated to determine the tolerance of bush beans (Phaseolus vulgaris) to flooding of various durations and at different growth stages. Plants were subjected to 11 flooding treatments lasting from one to 11 days. Flood treatments were initiated when plants reached either early vegetative growth stage (second true leaf opening), early reproductive stage (first flower opening on the main stem) or late reproductive stage (green seeds fill 1/2 of the pod cavity). In the first study, flooding during the early vegetative growth stage for one, 2 and 5 days resulted in both the number of pods produced and pod fresh weight being statistically similar to that of the non-flooded control. The remaining flood treatments resulted in pod fresh weights of 73% or less than the control weight. The number of surviving plants had more influence on the pod fresh weight than did flood duration. The number of pods produced per plant was correlated to pod fresh weight. Only one plant grown to either the early or late reproductive growth stage survived flooding for >24 h. There was a 21% yield reduction for plants flooded for 24 h during the early reproductive growth stage. Flooding for 24 h at the late reproductive stage resulted in a 50% yield reduction. In the second study, plants flooded during the early vegetative growth stage did not flower. Flooding during the late vegetative and flowering stages caused a 70 and 49% reduction in yield, respectively. Pod production slowed with increasing flood duration. Yield could be correlated to several plant physical characteristics. Linear relationships were found between yield components (pod number and weight) and flood duration, flood timing and leaf area. Greenhouse data indicate that yield reduction can be estimated from changes in plant characteristics resulting from flooding.