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Author(s) S.S. Al-Thabet
Affiliation Crops and Range Department, College of Agriculture & Food Sciences, King Faisal University, Al-Hassa, Kingdom of Saudi Arabia
Title Effect of Plant Spacing and Nitrogen Levels on Growth and Yield of Sunflower (Helianthus Annus L.)
Source Journal of King Saud University. Agricultural Sciences. Volume 19, No 1. (2007/1427)
Abstract To study the effect of plant density and N fertilizer levels on seed yield and its components of sunflower, a field experiment was conducted in Al-Hassa, Saudi Arabia during 2003 and 2004. The treatments comprised five rates of nitrogen (0, 50, 100, 150 and 200 kg N ha-1) and four plant spacing (20, 25, 30 and 35 cm between hills). Plant height, stem diameter, head diameter, number of seeds head-1, 100-seed weight, seed yield ha-1, seed oil percentage and oil yield ha-1 were estimated. Plant spacing significantly affected all estimated characters, except seed oil percentage. Twenty-five cm was observed as a suitable plant spacing, whereas higher or lower plant spacing had a negative effect on seed and oil yields ha-1. Nitrogen application markedly enhanced growth and yield, but resulted in sharp decrease in seed oil percentage. Two-hundred kg N ha-1 produced the highest seed yield ha-1, whereas the highest oil yield ha1 was obtained with the addition of 150 kg N ha1. Considering the superiority of 25 cm plant spacing and 150-200 kg N ha1 for seed and oil yields, it appears that they could be recommended for producing desirable yield under Al-Hassa area conditions.