Results of two years field experiment laid out to study the effect of nitrogen levels on plant water status, yield and quality of summer sunflower under different irrigation treatments, based on irrigation waterl cumulative pan evaporation (IW/CPE) values, showed that under deficit soil water condition, higher level of nitrogen showed the lowest leaf water potential. The yields obtained with irrigations applied at IW/CPE values of 0.75 and 1.0 or 10 days interval were at par and significantly increased with nitrogen levels up to 100 kg N ha−1. Water use efficiency of sunflower increased with low irrigation frequency and high level of nitrogen. The treatment of 50 kg N ha−1 and irrigation at 10 days interval resulted in highest oil content in sunflower seed.
Soil-water-plant relationship, soil water regime, water use efficiency
