Abstract

                                Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, during the Northeast monsoon (October-December) seasons of 1997 and 1998 in a split plot design to study the effect of crop geometry and split application of N on nutrient uptake and yield of rainfed sunflower. The main plot treatments consisted of three levels of crop geometry viz. 80, 100 and 120% of recommended population with a spacing 30 * 37.5cm 30 * 30 cm and 30 * 5 cm respectively and the sub-plot treatments formed six N split-levels and treatments were replicated thrice. The results revealed that the nutrient uptake of sunflower was higher with closer spacing of 30 * 25 cm than wider spacing of 30 * 37.5 cm. The plants under closer spacing (30 * 25cm) extract more moisture than wider spacing of 30 * 37.5 cm. The seed yield was higher at closer spacing (30 * 25cm) in 1997 (810 kg ha') and at wider spacing (30 * 37.5cm) in 1998 (1022 kg ha). In both the years the split application of nitrogen resulted in higher nutrient uptake and seed yield as compared to entire dose as basal dressing.

Key words : Sunflower, Crop geometry, N split application, Nutrient uptake and Seed yield.