Response of Some Sunflower Hybrids to Different Levels of Plant Density

The present investigation was conducted in the summer seasons of 2010, and 2011 at the Agricultural Research Station, Faculty of Agriculture, Alexandria University to study the effect of four plant populations (45000, 60000, 750000 and 90000 plants/ ha, respectively) on the field performance of five sunflower hybrids (Malabar, Romson 32, Horizon Record and Galla). The results showed that most of the studied yield and quality characters were significantly influenced by both plant densities, hybrids and their interaction. The lowest density gave the shortest plant and the highest values for leaf area, head diameter, 1000 seed weight, seed oil percentage and non-saturated fatty acids (oleic and linoleic). On the other hand, that density resulted in the significantly lowest value for days to harvest, leaf area index, dry matter yield, seed yield per ha, total oil yield and both saturated fatty acids, palmatic and stearic. The hybrid Record surpassed the other hybrids in most of the studied yield and quality characters. The plant density x hybrid interaction revealed that the hybrid record gave the highest values for average leaf area (0.56cm(2)), head diameter (33.9cm), 1000 seed weight (80.82g), seed oil percentage (45.9%), total oil production (1.23t/ha) and unsaturated fatty acids at the lowest plant density, whereas it gave the highest values for total dry matter production (16.3 t/ha), seed yield (3.6 t/ha) and total oil yield (1.23 t/ha), at 75000 plants per ha. (c) 2012 Published by Elsevier B.V. Selection and/or peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering