Response of sunflower cultivars to plant density and nitrogen

Abstract

Summary In a 2-year study, sunflower oultivar EC 69874 produced greater leaf area than EC 68415, but gave similar grain yields. The former was superior in leaf area, head size and yield per plant but was inferior in 100-seed weight. The leaf area was greater at lower plant density (5·5 plants/m 2 ), which resulted in higher 100-seed weight, number of seeds per plant and yield per plant than higher plant density (11·1 plants/m 2 ). Plant density had no influence on the percentage of filled seeds or oil content. Application of nitrogen improved the leaf area, flowerhead size, percentage of filled seeds, 100-seed weight, yield per plant and grain yield up to 60 kg/ha but decreased the oil content.