Correction - Time of planting effects on development, yield and oil quality of irrigated sunflower

Abstract

The effects of planting time on irrigated sunflower were tested at Emerald [Australia] during the 1969-70 and 1970-71 summer seasons. Plantings were done in Sept.-March. A growing degree day summation from a base of 0.degree. C (GDD0) was the most reliable index of commencement of flowering (coefficient of variation 5.7%). ''Sunfola'' commenced flowering at 1331 .+-. 76 GDD0. In both seasons significantly higher seed and oil yields were obtained from a Dec. planting (Seed yields 2628 kg ha-1 1969-70, 1808 kg ha-1 1970-71, oil yields 1025 kg ha-1 1969-70, 615 kg ha-1 1970-71). Lower yields at all times of planting in the 2nd season were attributed to rust infection (Puccinia helianthi Schw). A good correlation was obtained between oil quality (proportions of oleic and linoleic acids) and temperatures during the post flowering period. Oleic acid levels ranged 12-48%. Linoleic acid levels ranged 39-73%. Oil quality (percent linoleic acid) improved with late sowing in association with lowered temperatures.