The effect of organic and biological fertilizers on the growth and yield of two bean species ( Phaseolus calcaratus L. and Pachyrhizus erosus (L.) Urban) under drought stress

Organic agriculture is an integrated farming system, based on natural principles and laws, where the quality of products is more important than their quantity. Therefore, the present study was conducted in order to investigate the effect of two types of biological and organic fertilizers on the growth and yield of two types of beans under drought stress in the research farm of Shahrekord University. The experiment was carried out in the form of split split plots in the form of a completely randomized block design, and in three replications. The investigated factors include 1- drought stress at three levels of 60, 90 and 120 mm of evaporation from the surface of the class A pan and the second factor at four levels: EM biological fertilizer, Vinas organic fertilizer, a combination of both, and control; and the third factor: species of two levels (Mexican yam beans, red beans of the flower variety). In this experiment, the traits of plant height, number of secondary branches, relative humidity of leaf water, cell membrane stability index, number of pods per plant, biological yield, seed yield and harvest index were measured. The results of variance analysis of the data showed that the effect of the studied factors and their interaction (except for the interaction of stress × fertilizer on the number of pods per plant and cell membrane stability index) was significant on all traits. The results showed that the combined fertilizer treatment (vinas + EM) in red bean plant and stress 60 had the greatest effect on the characteristics of seed yield (8834 kg/ha), harvest index (64.66%), plant height (117 cm), the number of pods per plant was (32.33), and the number of sub-branches (14). In the same fertilizer treatment and in the control stress treatment, the greatest effect was on the trait of cell membrane stability index in red bean plant (57.7%) and relative humidity. Leaf water (91.88%) and biological yield (35710 kg/ha) were in Mexican yam plant. Generaly, it can be said that this experiment showed the superiority of combined fertilizer treatment on red bean plant under drought stress compared to Mexican yam plant.