Cotton Yield Response to Sulfur as Influenced by Source and Rate in the Çukurova Region, Turkey

Rapid expansion in nitrogen and phosphorus usage occurring over the past two decades in turkey without an accompanying increase in the addition of sulfur (s) and decreased atmospheric so_2 emissions has possibly created a major plant nutrient s deficit. attention needs to be paid to s requirement of cotton producing environments where s deficiencies may become somewhat more common due to increased use of s free fertilizers, adoption of high yielding cultivars and more intensive cropping systems, and lower atmospheric s deposits. the effectiveness of sulfur fertilization for cotton grown in the region is not known. this study evaluated the effect of sulfur fertilizers on the yield and fiber quality of cotton (gossypium hirsutum l). four s rates, (0, 15, 30 and 45 kg ha^-1) were applied to the plots as elemental and gypsum at planting. the most beneficial effect on the yield of cotton was produced by the rate of 30 kg s ha^-1. significant effects on the number of harvestable bolls plant^-1 coupled with significant effects on boll weight, resulted in seed cotton yield being significantly higher with 30 kg ha^-1 as compared to other rates. all s rates, except 45 kg s ha^-1 produced significantly higher fiber length uniformity. applications of 30 and 15 kg s ha^-1 resulted in 4.0 to 2.0% increase in micronaire. the results suggest that 30 kg ha^-1 gypsum supplied sufficient sulfur optimum yield under semiarid conditions. cotton yield increase due to sulfur fertilizer indicates producers have the flexibility to apply sulfur fertilizer.