Effect of vermicompost on some morphological, physiological and biochemical traits of bean (Phaseolus vulgaris L.) under salinity stress

Vermicompost can play an effective role in plant growth and development and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances and plant growth regulators and also high levels of macro and micro nutrients. The aim of this study was to investigate the effects of vermicompost and salinity interactions on some morphological and physiological features and concentration of mineral elements of bean (Phaseolus vulgaris L. cv. Light Red Kidney) cultivar. A factorial experimental with five different volumetric ratios of vermicompost and sand, including to: 0:100; 10:90; 25:75; 50:50 and 75:25 and four levels of salinity [20, 40, 60 and 80mmol l(-1) sodium chloride (NaCl)], and control was conducted base on Randomized Complete Block Design with three replications. Bean seeds were sowed in plastic pots, the seedlings being sampled 42days old (flowering stage).The results showed that vermicompost had significant effect on all studied traits under stress and non-stress (p 0.05).In this experiment, the vermicompost significantly increased the photosynthetic rate and concentrations of potassium (K+) and calcium (Ca-2)(+)in leaf and root tissues. In salinity levels of 20, 40 and 60mmol l(-1)NaCl, all subjected ratios of vermicompost and in 80mmol l(-1)NaCl the ratios of 10% and 75% vermicompost, significantly ameliorated negative effects of salinity. In both stress and non-stress conditions, using 10% volume of vermicompost is recommended to improve the growth of bean plants.