The response of pigeonpea cultivars to short durations of waterlogging

Abstract

The effects of short durations of waterlogging was investigated in three cultivars of pigeonpea ( Cajanus cajan (L.) Millps); Tobago pea, Chag pearl and ICPL-19 grown in pots under greenhouse conditions at four waterlogging treatments (Control, WL1, WL2, WL3, and WL4). Waterlogging treatments resulted in an increase in stomatal resistance, and reduced rates of transpiration and net photosynthesis in all the cultivars, but cultivar differences were not evident. With increasing number of cycles of waterlogging, there were increases in the stomatal resistance and reduction in rates of transpiration and net photosynthesis. Waterlogging also resulted in wilting, chlorosis, senescence and abscission of lower leaves after as little as two days of waterlogging. Leaf area development, dry weight accumulation per plant and partitioning were substantially reduced by waterlogging treatments, but the reduction in leaf area and dry weights were consistently greatest in ICPL-19 than Tobago pea and Chag pearl. The adverse effect of waterlogging observed in this study was associated to the greater degree of root damage in all cultivars which in turn resulted in an increase in the resistance to water flow.