Abstract

A field experiment was conducted with mustard (Brassica juncea, var. B-85) during rabi seasons of 2010–11 and 2011–12 to study the effect of sulphur (S) oxidizing strains of Thiobacillus thioxidans along with S, amendments on the yield parameters. Sulphur @ 20 kg/ha was applied through elemental S, gypsum and pyrite and three Thiobacillus strains RS 002, RS 004 and RS 005 were inoculated in soil. Mustard yield at maturity, S containing plant parts and soil sulphate at different intervals of growth period were evaluated. The seed yield on average was 14.5% higher in elemental S over control which further increased to 30.6% along with inoculated S oxidizers. The oil yield which was 25.7% higher in elemental S or gypsum over control after 2nd year increased up to 42% with S oxidizing inoculants RS 004. Sulphur content in seeds was highest in gypsum or elemental S and increased in the 2nd year of study. On an average, the seed S increased 19.1% with gypsum over control which increased further to 22.3% when S oxidizers were inoculated in soil. Sulphur in stover did not bear any significant difference with the year of study. For most yield parameters, the strain RS 004 was outclassing. The soil sulphate was found to increase with time in both the years; the values were higher for gypsum and elemental S than pyrite. Both elemental S and gypsum were equal in effect after two years. Soil sulphate increased by 6.99 mg/kg for gypsum addition after two years as against a mining of 0.52 mg/kg in the control.