The effect of Thiobacillus and sulfur application on yield and yield components of common bean (Phaseolus vulgaris L.) under water deficit conditions

Introduction During recent years, the adoption of soil biotechnology has received noticed for aiming to use the potential of helpful soil organisms to maximize crops instead of trying to improve soil. Today what encourages developed countries to produces and consume bio-fertilizers and bacteria are the environmental side effects caused by the inadvertently imbalanced consumption of chemical fertilizers. Bean is seventh major world food crop that is often affected by adverse environmental conditions such as drought, Despite beans economic importance, few studies have been done on the genetics and genetic resource assessment, Given the importance of water deficit, Thus, the objectives of this study attempted to identify the most appropriate fertilizer treatment for varieties of bean under water deficit stress on the greenhouse experiment by passing through several stages of sulfur and Thiobacillus bacteria application and reviewing the given results Materials and methods In order investigate the effect of Thiobacillus and Sulfur on photosynthetic pigments in different common bean (Phaseolus vulgaris) cultivars under water deficit, the greenhouse experiment was carried out in factorial form using a completely randomized design with three replicates at the greenhouse of Research Station of the Islamic Azad University, Tabriz Branch, Iran, during the 2016. The studied factors included: (A) cultivars of bean a1) white bean (Dorsa), a2) red bean (Akhtar) and a3) pinto bean (Sadri) in four stages of fertilizer (B), b1) control, b2) 300kg/ha sulfur, b3) Thiobacillus and b4) sulfur + Thiobacillus, Under three water deficit condition (C) c1) control, c2) No irrigation from flowering stage and c3) No irrigation from poding stage. In this study used from two flowerpot (8kg) for each treatments. The following plant growth parameters were measured when about 65-75% of pods were matured: No. pod, No. full pod, 100-grain weight, biomass, grain yield and harvest index. SAS software was used to check the normality of the data, analysis of variance, and means comparison. The mean of the treatments were compared using the Duncan’s test at p< 0.05. Results and discussion Results revealed that water deficit, especially No irrigation from flowering stage reduced harvest index, yield, biomass, 100 seed weight, number of pods and field pod but No irrigation from poding stage had fewer negative effect on measured traits. This decrease in most cases reduced negative effects of stress by applying the Thiobacillus especially with sulfur. Thiobacillus bacteria provided more suitable condition to improving bioactivities of soil and caused to increasing measured traits through absorbing nutrients by root in compared with control treatment. But whatever increased during the period of stress, subsequently the positive influence of the bacteria and sulfur was lower. Conclusions In all of traits studied, control has the highest value and after that was stress at poding stage and flowering stage. Water deficit due to flowers loss and reduced number of pods and eventually reduced yield. Among the cultivars Dorsa had the less success to Resistance, and application Thiobacillus + sulfur could not make the most impact for Resistance to stress in this cultivar. Recent studies indicated that using Thiobacillus + sulfur also improving soil physiological structure and also increase available mineral nutrients to coexistent plant. All cultivars showed intense sensitivity to stress (especially during flowering stage) and we can by applying Thiobacillus + sulfur in soil help to increase solubility of minerals and their absorption ability for increased plants resistance to stress.