Influence of plant population on yield and yield components of irrigated sunflower in southern New South Wales

Abstract

Three experiments conducted in the Murrumbidgee Irrigation Area of southern New South Wales examined the influence of plant population on the yield and yield components of irrigated sunflowers. Populations ranged from 25,000 plants ha-1 to 140,000 plants ha-1. Furrow irrigation was employed with rows spaced 76 cm apart. In two of the experiments the wide range of plant populations examined had little effect on seed yield. Individual seed weight (g 1000-1) and seed number per head interacted with plant population so that seed yield was only marginally affected. In the remaining experiment, insufficient total dry matter production without improved harvest index prevented the attainment of an acceptable seed yield. There was a consistent trend for harvest index to fall with increasing plant population. Values recorded ranged from 0.36 to 0.23. Plant population had little effect on oil percentage. A plant population of 50,000 plants ha-1 is suggested as a minimum recommendation for irrigated sunflowers in southern New South Wales.