Recovery from water stress in five sunflower ( Helianthus annuus L.) cultivars. I. Effects of the timing of water application on leaf area and seed production.

For sunflower plants grown at a density of 5 m^-2, maximum leaf areas per plant ranging between 0.2-2.2 m^-2 resulted from using 5 cultivars of different maturity and imposing 4 different water treatments. Seed production increased with the number of irrigations supplied, and in the irrigated treatments it was positively correlated with time to anthesis: later cultivars yielded better. The longer duration lines were most suited to irrigation, since they permitted establishment of more leaf area. The interaction between the effects of irrigation management and plant maturity on seed yield is discussed.-from Authors