Plant population and nitrogen effects on achene yield and quality of Sunflower (Helianthus annuus L) hybrids

Abstract

The experiment was conducted to study the effect of varying plant population and nitrogen rates on growth, development, yield and quality of sunflower hybrids at research area of University College of Agriculture, Sargodha, during spring season, 2011.The treatments include two hybrids (Hysun-33 and S-278) and three planting densities (8.33, 6.66 and 5.55 plants m-2) with three rates of nitrogen (100, 125 and 150 kg ha-1). The obtained results revealed that there was a significant difference for days taken to anthesis (R 5.8 stage) and physiological maturity (R 9 stage), and achene yield (AY) as well as achene oil contents (AOC) in both of the hybrids except Leaf area index (LAI) and total dry matter (TDM). The hybrid S-278 started reproductive stages and matured earlier and gave higher achene's yield (3.34 t ha-1) than hybrid Hysun-33 (2.73 t ha-1). Increasing plant density increased the days taken to anthesis (DA) and physiological maturity (DPM), LAI, TDM, AY, AOC in sunflower. Similarly, with increasing nitrogen application phonological duration, LAI, TDM and AY was increased but AOC were reduced. The interaction between hybrids and planting densities (HxD), hybrids and nitrogen (HxN), Planting density and nitrogen (DxN) were non-significant for all the parameters.