the effect of bio-fertilizer and chemical fertilizers (phosphate and zinc) on yield and yield components of two cultivars of bean (phaseolus vulgaris l.)

introduction: use of unbalanced chemical fertilizers especially p, having low absorption efficiency and low solubility compounds with soil components, has resulted in the production and use of bio-fertilizers (17, 23 and 29). bio-fertilizer is a preservative material consisting of one or several specific beneficial micro-organisms or their metabolic products used to supply plant nutrients and development of root systems (29). there are a lot of micro-organisms in soil capabling help to plant nutrition and uptake of nutrient elements in different ways that can be mentioned by the dual symbiotic relation between micro-organism and plant. mycorrhizal fungus and plant growth promoting rhizobacteria (pgpr) such as azotobacter and pseudomonas are able to increase uptake of nutrient elements particularly when they are applied with others and hence they increase the yield of different crops (12, 14; 24 and 30). p solubilizing fungus and bacteria facilitate uptake of slowly diffusing nutrient ions such as p, zn and cu and increase their availabilities usually by increasing volume of soil exploited by plants, spreading external mycelium, secreting organic acids, production of dehydrogenase and phosphates enzymes and reducing rhizosphere acidity (9, 15, 19, 23 and 26). the main beneficial use of micro-organism is increasing of host plant growth. it can be done with increase of nutrient elements uptake. the main objective of this study was to evaluate the effect of p and zn bio-fertilizers on yield, yield components and shoot nutrient elements in two cultivars of bean for the first time in the chaharmahal-va- bakhtiari province. material and methods: this field experiment was carried out as a factorial in a randomized complete block design (rcbd) with three replications. the treatments of this research consisted of two cultivars of chiti bean (talash and sadri), four levels of p (p0: control, p1: chemical fertilizer on the basis of soil test, p2: 50 percent of recommended p + bio-fertilizer (p), and p3: bio-fertilizer (p)), three levels of zn (zn0: control, zn1: 50 kg ha-1 zinc sulphate, and zn3: bio-fertilizer (zn)). bio-fertilizer (p) treatment consisted of mycorrhizal and five strains of azotobacter chroococcum. bio-fertilizer (zn) treatment consisted of pseudomonas aeruginosa strain mpfm and pseudomonas fluorescent strain 187. grain inoculation (5%) was done in shadow and after drying, inoculated grains were immediately cultivated. two g of mycorrhizal fungus was applied at the base of the grain hole just prior to sowing. chemical fertilizers were applied from tsp at a rate of 100 and 50 kg ha-1 in p1 and p2 respectively, 50 kg ha-1 znso4.7h2o in zn1 and 50 kg ha-1 urea as a starter before planting. the size of each plot was 3 × 4 meters. statistical analysis was done with sas) statistical software. duncan’s multiple range test was used to separate means. results and discussion: the results revealed that there were significant differences between the two cultivars on seed yield, number of seeds per pod, 100 seed weight and concentrations of nitrogen (n), potassium (k), and zn, but there was no significant difference between the other parameters. p treatment showed a significant effect on the examined parameters except the number of seeds per pod. the highest content of yield (3446 kg ha-1) was observed in p2 treatment (18.5% seed yield increase). zinc treatment also had a significant effect on the parameters being studied except the number of seed per pod and manganese (mn) concentration. the maximum seed yield (3339 kg ha-1) was monitored in zn1 and zn2 treatments. the effect of interactions between p and zn was significant on the number of pods per shrub, 100 seed weight and k concentration, but it was not significant on the other parameters. however the highest content of seed yield (3520 kg ha-1) was obtained from p2zn1 (32.5% seed yield increase) treatment. our results were similar to findings of other researchers (1, 3, 12, 15, 17, 26 and 30). they reported that dual inoculation increases plant productivity. in this study, phosphate and zn bio-fertilizers caused an increase in yield, yield component and shoot nutrient by increasing nutrient uptake, photosynthesis, growth hormones and creating favorable growth conditions. also results showed that the consume of p fertilizers were decreased (50 percent) with proper integration of chemical and bio-fertilizers. these results correspond with the results of other researchers (17, 22, 23, 24 and 27). conclusion: in this research proper integration of bio- and chemical fertilizers was shown to increase yield and yield components with increasing and improving p and other nutrients’ uptake in both bean cultivars. the result also indicated that combining bio and chemical phosphate fertilizers increased the efficiency of phosphate fertilizers by 50 percent. sadri cultivar is a suitable cultivar for chaharmahal-va- bakhtiari province and regions with a similar climate.