Effects of thiobacillus bacteria on physiology and vegetative growth of pomegranate

چکیده مقاله

The climate change and consequent degradation of soil and water resources have led to difficult conditions for farmers; thus, they should make intelligent decisions to face these statuses. Managing soil nutrient and mineral uptake by plants and its feasibility under harsh environment must be considered. Therefore, the present research was conducted to investigate the response of pomegranate variety Shishe Kab to Thiobacillus bacteria (B) and sulfur (S) fertilization. Treatments included sulfur fertilization (three levels: 0, 500 and 1000 g−1 tree) and inoculation with Thiobacillus bacteria (two levels: inoculated and non-inoculated). Totally, sulfur fertilization and inoculation with bacteria improved physiological and biochemical aspects and fruit production of pomegranate. Supplying S decreased soil pH, which the lowest value (5.2) was recorded in 500 g S tree−1 when accompanied with bacteria. Soil electrolyte leakage (EL) increased, when sulfur incorporated or when bacteria added to the soil. The interactive effects of B �S was significant on fruit diameter and weight, chlorophyll (Chl), carotenoid and potassium content, which were improved, although non-inoculated plants also showed high values of potassium content. Anthocyanin and total carbohydrate improved when bacteria inoculation was done; however, total acidity (TA) and total soluble solids (TSS) showed a significant decrease. The EL variable significantly decreased and tissue water content increased in this experiment, when inoculation or sulfur fertilization was used. The results obtained from present study emphasized on the necessity of using sulfur and Thiobacillus bacteria in increasing growth and yield and also chilling tolerance of pomegranate trees.