Effect of powdery sulphur with / Less Thiobacillus on the yield of Colza.

Field experiment was conducted in a randomized complete block design with 3 replication in a paddy field at Rice Research Institute of Iran (RRII) in guilan province (Rasht) and its deputy in Mazandaran province (Amol) during Oct.- May (2002-2003). Five elemental sulphur rates (0, 25, 50, 75 and 100 kg S /ha) which were calculated according to soil analysis test, with or without thiobacillus inoculum (7%w /w), were applied at planting. Of course, the rates of sulphur were (0, 200, 400, 800 and 1600 kg S /ha) in Rasht at the first year and the thiobacillus inoculum was 40%w /w in two places at the second year. N, P, K fertilizers were applied according to recommended rates and the seeds of rapeseed Var. PF 7045/97 in Rasht and Var. Hayola 308 in Amol were sowed in 2 * 3m plots. Other cultivation operations were carried out similarly and the grain yield of each plot was harvested, threshed, weighed and the oil content was measured. Records analyzed and the means compared according to statistical methods. The average yields of treatments at 3 replication were1744.33, 1739.64 and 1734.81 kg /ha respectively. Analysis of variance in Rasht showed that there were no any significant differences between treatments, in other word elemental sulphur rates (with or without Thiobacillus) had no any significant effect on grain yield but the mean comparison of rapeseed grain yield was shown two comparison level by DMRT. Analysis of variance in Amol showed that there were significant differences between treatments at 1% level on rapeseed yields so that the highest yield (2334.33 kg/ha) was obtained from 75 kg sulphur per hectar, a yield increase of 590.75 kg/ha compared with the control treatment. Application of sulphur was not significantly effect on percent of seed oil and application of thiobacillus was not significantly effect on seed yield too.