Effect of irrigation on physiology and yield of sunflower hybrids.

Abstract

The effect of four regimes of irrigation on physiological and morphological characteristics of sunflower hybrids was studied at National Agricultural Research Centre (NARC), Islamabad, Pakistan. The four irrigation levels were control (no-irrigation), heading stage, heading + flowering stages, and heading + flowering + grain filling stages. Sub plot size of 4.5 m x 5 m was maintained and randomized complete block design in split plot arrangement having 5 replications were used. Water regimes/ irrigation were kept in the main plot while hybrids (Parsum-1 and SF-187) in the sub plot. Maximum seed yield (2680 kg ha -1 ) was obtained with three irrigations when compared with other treatments. Among the hybrids, SF-187 produced more yields (2440 kg ha -1 ) than the hybrid Parsun-1 (2333 kg ha -1 ). Oil content was lower (41.01%) in treatments receiving three irrigations. Seed yield with three irrigations was 24.83% higher than the control plot. Maximum leaf area index was observed when irrigation was given at 90 day interval after emergence of the sunflower (third irrigation). The same trend was also observed in dry matter accumulation and crop growth rate.