The effect of sulphur and Thiobacillus on nutrient absorption, growth and essential oil in lemon balm (Melissa officinalis L.)

Background & Aim: In order study the effect of Thiobacillus, sulphur and organic materials on vegetative growth and essence production in lemon balm (Melissa officinalis L.) was conducted in pots in field condition at Shahrekord, Iran on 2008. Experimental: The factors were ten soil treatments inclusive 200 kg/ha sulphur, 400 kg/ha sulphur, 600 kg/ha sulphur, 200 kg/ha sulphur + Thiobacillus, 400 kg/ha sulphur + Thiobacillus, 600 kg/ha sulphur + Thiobacillus, 200 kg/ha sulphur + Thiobacillus + organic materials, 400 kg/ha sulphur + Thiobacillus + organic materials, 600 kg/ha sulphur + Thiobacillus + organic materials and without application of sulphur, Thiobacillus and organic materials. Results & Discussion: The results revealed significant differences between treatments in cupper, zinc, iron and manganese content in soil after harvesting and fresh weight, dry weight and number of lateral stems in plants. Also, differences between essence content in dry plants in various treatments were significant. Treatment of 400 kg/ha sulphur + Thiobacillus + organic materials and control demonstrated the highest and lowest cupper and manganese content in soil after harvesting and fresh weight, dry weight and lateral stems in plants respectively. In this research we observed the significant effect of sulphur on content of essential oil.  The highest essence content in dry plants was produced by 400 kg/ha sulphur + Thiobacillus + organic materials and 600 kg/ha sulphur + Thiobacillus + organic materials. The correlation between traits showed that the more dry weight, Fe and Zn content in soil made the more essence content.