Osmotic Adjustment in Chickpea in Relation to Seed Yield and Yield Parameters

Abstract

To ascertain the role of osmotic adjustment (OA) in drought tolerance of chickpea (Cicer anetinum L.), eight cultivars differing in OA capacity were field grown under a line source sprinkler irrigation system. This imposed a soil moisture gradient on either side of the line source. The cultivars were divided into high and low OA groups and crop performance was assessed group-wise at three growth stages and at the time of harvest. A two-way increase in water stress was observed, along the soil moisture gradient and across the growth stages. As a result, water potential, osmotic potential, and relative water content decreased progressively with increasing soil moisture stress and age of the crop, regardless of OA groups. As compared with low OA cultivars, high OA cultivars generally showed an improved plant water status. High OA cultivars proved significantly superior to low OA ones in seed yield and most of its parameters. The yield benefit was 26 and 48% at moderate and severe moisture stress levels of the line source. This coincided with osmotic adjustment ranging from 0.28 to 0.48 MPa and from 0.37 to 0.71 MPa, respectively, at various phases of reproductive growth.