Effect of sulphur and zinc on quantity and qualitycharacteristics of corn

Sulfur and zinc are two essential elements for different crops. In order to study the effects of sulphur and zinc application on the yield and quality of grain corn, four field experiments were conducted in research stations of Kermanshah, Kerman, Qazvin and Behbahan during 2001andrsquo2003. These studies were conducted by using a factorial test in randomized completely block design with 12 treatments and four replications. The treatments were four levels of zinc (0, 10, 20 and 30 kg.ha-1 or 0, 40, 80 and 120 kg.ha-1 zinc sulfate) and three levels of sulphur (0, 200 and 400 kg.ha-1). The results in Kermanshah indicated that there was no significant difference among treatments in view of grain yield. The highest yield,9156 kg.ha-1 was obtained with 400 kg.ha-1 sulphur and 80 kg.ha-1 zinc sulphate which in comparison with control, increment of yield was 774 kg.ha-1. By zinc and sulphur application, seed number in ear, seed number in diameter of ear, length ear , 1000-grain weight were increased and concentration of nutrient elements were changed as follows: potassium (0.01- 0.7%), nitrogen (0.08 - 0.33%), zinc (1-5 andrsquog.g-1), boron (0.04 - 0.55 andrsquog.g-1) and phosphorous (0.08 - 0.2 %). In general, in grain corn, application of 80 kg.ha-1 zinc sulfate and 400 kg.ha-1 sulfur is recommended in soils with properties of Fine Mixed Thermic Vertic Calcixerepts in Kermanshah province. The results of three years research in Qazvin showed that sulphur application increased yield but there was no significant difference among sulfur treatments. The highest yield obtained from application of 30 kg.ha-1 zinc. There was a significant difference among S*Zn interaction at 1% levels. The highest mean yield obtained from S200Zn0 which was about 3 t.ha-1 more than control. The results, also, showed that different treatments had no significant difference in the other aspects. Based on obtain data, in general, application of 80andrsquo120 kg.ha-1 zinc sulfate and at least 200 kg.ha-1 sulphur is recommended in soils with similar properties in Qazvin province. The results in Behbahan indicated that seed number in ear, diameter and length of ears, 1000-grain weight, Zn concentration in leaves were increased by zinc application and were significant at 5% levels. The highest yield, 10470 kg.ha-1 was obtained with 400 kg.ha-1 sulphur and 120 kg.ha-1 zinc sulfate were significant at 1% levels. The results also showed that yield increased by zinc application and were significant at 1% levels. In addition, the highest zinc concentration (69.1 andrsquog.g-1) and the highest seed number in ear 35 (610) obtain with S400Zn30.In general, in grain corn, application of at least 80 kg.ha-1 zinc sulfate and at least 200 kg.ha-1 sulphur is recommended in soils with similar properties in Behbahan. The results in Kerman showed that yield, seed zinc content and the 1000 grains weights were affected by the fertilizer treatments. The 1000 grains weight and seed zinc content was increased by all of the treatments but only S200 was significant in rate of %5. In addition, zinc concentration in grain increased by all of treatments but only S400 Zn80 was significant in rate of 5%. In general, in grain corn fields of Kerman province, application of 40 kg.ha-1 zinc sulfate and 200 kg.ha-1 sulphur is recommended in soils with similar properties. Based on obtained data from four station, results indicated that the highest mean grain yield (9053 kg.ha-1) was achieved with application of 40 kg.ha-1 zinc sulfate while the mean yield of control were 8200 kg.ha-1. In other words, this treatment in compare with control had about 1.5 t.ha-1 increment yield. Application of Zn and S in the same time had significant difference (andrsquo=5%) on grain yield, 1000-grain weight, Fe and Zn content in seeds and total uptake of N, P, Zn, Mn and Fe. There were significant difference among zinc treatments and control on the grain yield. Although, the highest mean grain yield (9452 kg.ha-1 ) was obtain with 30 kg.ha-1 zinc, but there is no significant difference between zinc levels. For sulfur, there was a significant difference among S400 and control on the grain yield. The heights mean grain yield was obtained from 400 kg.ha-1 S while had no significant difference with 200 kg.ha-1 S. Based on general results, in order to obtain 10 t.ha-1 grain corn, application of at least 10 kg.ha-1 zinc or 40 kg.ha-1 zinc sulfate and 400 kg.ha-1 sulphur accompanying thiobasilouse is recommended.