Effect of phosphorus application on growth, chlorophyll and proline under water deficit in clusterbean (Cyamopsis tetragonoloba L. Taub)

A study was carried out on clusterbean (Cyamopsis tetragonoloba L. Taub) cv. HG-365 under pot-culture. Three levels of phosphorus i.e., 15, 30 and 60 mg kg⁻¹ soil were supplied in two split doses at week's interval in the form KH₂PO₄ one week after sowing. Water stress was created by with holding irrigation at vegetative, flowering and pod-filling stages. Water deficit decreased the dry weights of leaf, stem and roots in general. The chlorophyll content of the leaf was also decreased by water-deficit but there was accumulation of large amount of proline in the leaf. Treatment with phosphorus proved effective in improving the chlorophyll content as also dry weights of plant parts at all the stages. On the contrary, proline content of the leaf decreased by phosphorus treatment. The present investigation revealed that phosphorus treatment was effective to large extent in alleviating the effect of water deficit in clusterbean.