Productivity Of Sunflower Hybrids As Influenced \ud By Sulphur nitrogen Nutrition And Varying Plant Population

The present research \ud work was carried out to investigate the effect of sulphurnitrogen \ud nutrition and varying plant population on productivity of sunflower \ud hybrid at the agronomic research Area, University of Agriculture \ud Faisalabad. Two years field oriented research experiments were \ud conducted for 2006 and 2007.In the first experiment sunflower hybrid \ud Hysun-33, was subjected to four sulphur level (0, 40, 80, 120 Kg \ud ha-1) and four nitrogen levels (0, 40, 80,120Kg ha-1). The \ud experiment was laid out in RCBD factorial with three replications. \ud In the second experiment three sunflower hybrid viz., FH-331 (early \ud maturing), SF187 (medium maturing) and Hysun-33 (late maturing) were \ud tested at three row spacing (45cm, 60cm and 75cm).The variation in \ud agronomic and physiological characteristics of sunflower was \ud analyzed with varying levels of sulphur and nitrogen. During both \ud years of study sulphur and nitrogen application @ 80 and 140 Kg ha-1 \ud produced maximum achene yield (3167-3000Kg ha- 1), which was the out \ud come of better yield contributing attributes (higher leaf area, \ud maximum crop growth rate, better light interception, dominant head \ud size, higher 1000- achene weight).On an average maximum oil yield of \ud 1090 and 1121 Kg/ha were obtained with the application of 80 and 140 \ud Kg ha-1 sulphur and nitrogen, respectively.<br>\ud An increase in protein contents (%) was experienced with increasing \ud sulphur levels, and vice versa with enhancing the nitrogen levels. \ud Radiation utilization efficiency for dry mater and grain was also \ud significantly increased with higher nitrogen rate and sulphur \ud application @ 80 Kg ha-1. Computation of benefit cost ratio (BCR) \ud revealed that the highest BCR 2.38 was also pertinent to the same \ud treatment in sunflower are 80 and 140 Kg/ha-1, respectively. In the \ud second experiment the hybrid Hysun-33, which was a late maturing \ud hybrid, not only recorded highest leaf area index, but also \ud experienced maximum crop growth rate, highest plant height, greatest \ud number of achenes, and maximum achene yield. On an average \ud Hysun-33(late maturing type) produced significantly higher achene \ud yield (3033-2888Kg ha-1), planted at 60cm apart rows, and \ud SF-187(medium maturing hybrid) harvested maximum achene \ud yield(2783-2740Kg ha- 1), when sown at 45 cm wider rows. The early \ud maturing (FH-331,a local hybrid) responded well to the row distance \ud of 45 cm and produced highest achene yield of 2633-2533 Kg ha-1. \ud Although, with increasing rows spacing from 45-75cm, the<br>\ud sunflower crop resulted in larger heads, possessing more achenes per \ud head, and heavier individual achene, but the boost in yield of the \ud hybrids FH-331 and SF-187 with decreasing the row spacing \ud (increasing plant population) was principally associated with more \ud achene number per unit area, higher leaf area index and maximum crop \ud growth rate. Therefore, it is concluded that under tropical to \ud semi-arid region like the experimental area (located at 73.09o East \ud longitude and 31.25o North latitude and at an altitude of 184 m), \ud the best sulphur and nitrogen doses to get maximum achene \ud yield.Highest achene yield 3084 kg ha-1 was recorded where sulphur \ud was applied at the rate of 80 kg ha-1for along with 140 kg ha-1 \ud nitrogen. Computation of benefit cost ratio (BCR) revealed that the \ud highest BCR 2.38 was also pertinent to the same treatment in \ud sunflower are 80 and 140 Kg/ha-1, respectively. Regarding hybrids \ud and their planting density, late maturing hubris like Hysun-33 \ud should be planted at 60 cm apart rows with plant to plant distance \ud of 22.5. Medium and early maturing sunflower hybrids may be \ud preferred to be sown at 45 cm apart rows with plant to plant \ud distance of 22.5 cm