Journal of Plant Nutrition, vol.26, no.7, pp.1483-1498, 2003 (SCI-Expanded)
Deficiency of sulfur (S) has been recognized as a limiting factor for crop production in many regions of the world. A survey study was initiated to determine the current S nutritional status of wheat plants in Ankara, Turkey in the cropping season of 1999-2000. Owing to the results of the survey study signing soil and plant S deficiency, a greenhouse and field study were conducted during 2000-2001 on the effect of S on yield and yield components of bread (Triticum aestivum L. cv. Bezostaja) and durum (Triticum durum L. cv. Kiziltan) wheat cultivars. According to the survey study results, more than 50% of the soil, plant straw, and grain samples contained lower S than the critical limits. Significant positive correlations were observed between total and extractable soil-S (r=0.4799), and also between both the total and extractable soil-S and grain-S (r=0.3097 and r=0.4162). Additionally significant positive correlation was observed between straw and grain-S (r=0.4500). Yield and some of the yield components in both wheat cultivars were significantly responded to the application of S fertilizer in the greenhouse and field experiments, which conducted with a soil containing 12.78 mg extractable S kg-1 soil. Dry weights of Bezostaja and Kiziltan increased from 4.38 to 4.72 g pot-1 and 3.03 to 3.26 g pot-1 respectively, at the minimal dose of S (10 mg S kg-1) application in the greenhouse study. In the field study, grain yield increased from 3472 to 4869 kg ha-1 in Bezostaja and 4787 to 5804 kg ha-1 in Kiziltan at the minimal dose of applied S (20 kg S ha-1). After these levels of S application, the differences among the S levels with respect to yield were found not to be significant both in the greenhouse and field study. Concentration of S in plant, grain yield per spike and harvest index for both cultivars, and spike number m-2, spike length, fertile and sterile spikelet number per spike for Bezostaja, and thousand kernel weight for Kiziltan were responded positively to S fertilization in field conditions. On the other hand, the ratio of N/S in the grain and shoots of both cultivars decreased by S fertilization.