Evaluation of the effects of application of plant growth regulator rhizobacteria on the important agronomic traits and physiological characteristics of red beans (Phaseolus vulgaris L.)

In order to investigate the effects of phosphorous and potassium fertilizers on some important morphological traits, agronomic characteristics and yield of red bean cultivars, an experiment was conducted at Agricultural Research Farm of Islamic Azad University, Arak, in the summer of 2013-2014 and in two consecutive years. This experiment was conducted as split plot based on randomized complete block design with three replications. Experimental treatments included the use of bio fertilizers at four levels of non-use, application of phosphorus biofertilizer, potassium biofertilizer and phosphorus biofertilizer + potassium biofertilizer and four red bean genotypes, Goli, D81083, Derakhshan, and KS31169/3. The application of biological fertilizers was carried out early in the vegetative period and also in the pre-flowering stage. The results showed that application of biological fertilizers could significantly affect the yield of single plant, number of seeds per plant, number of pods per m2, number of branches, chlorophyll a, Chlorophyll b, chlorophyll a to chlorophyll b ratio, ratio the shell weight by the weight of the entire pod and potassium-phosphorus ratio. In this study, Goli cultivar produced the highest seed yield of 8.71 g plant-1. Also, the grain yield of beans increased by 25.5%. from 6.56 g plant-1 in the absence of biofertilizers to 8.80 g plant-1 in combined fertilizer application. The genotypes showed significant differences in all of the studied traits, but the interaction between application of fertilizers and genotype was significant only in number of seeds per plant, number of pods per square meter. Thus, using biofertilizers, in addition to quantitative increase and absorption of essential elements by stimulating growth, can improve quality characteristics of red beans.