THE EFFECT OF PLANT GROWTH PROMOTING RHIZOBACTERIA IN REDUCING NITROGEN AND PHOSPHORUS FERTILIZERS APPLICATION IN SUGARCANE
This study was performed in order to investigate the effect of Plant growth-promoting rhizobacteria in reducing nitrogen and phosphorus Fertilizers Application in Sugarcane. The field experiment of this study was in the form of Split–block design with subplots in stips with four replications and three factors, including bacterial factor at four levels (control, Enterobacter cloaca, Pseudomonas putida and a combination of two types of bacteria), nitrogen factor at three levels (50, 75 and 100% recommended nitrogen for sugarcane (and phosphorus factor at three levels (50, 75 and 100% recommended phosphorus for sugarcane), was carried out in 2016-2017crop year in DC7-10 research farm of Dehkhoda sugarcane agro-industryin Ahvaz, in the southwest of Iran, on CP73-21 sugarcane variety. According to the analysis of variance tables, simple and interaction effects of the tested treatments, in the case of quantitative traits, including stalk yield, height, diameter, stalk density, percentage of nitrogen and phosphorus of leaves, chlorophyll content, LAI and HI in sugarcane were significant at the level of 1% probability. Comparison of means showed that the application of simultaneous application of growth-promoting bacteria along with the application of 75% recommended nitrogen and phosphorus for sugarcane, compared with the control treatment (application of 100% recommended nitrogen and phosphorus for sugarcane, without the use of bacteria), Was able to succeed in these traits 96.9%, 98.1%, 95.7%, 96.3%, 100.2% ,101.9%, 91.2% and 94.8%, respectively and Provide 21/9, 23/1, 20/7, 21/3, 25, 25, 16.2 and 19.8% of the nutrients of nitrogen and phosphorus for sugarcane, respectively, and is saved the same amount of nitrogen and phosphorus consumption for sugarcane. Also, regarding the sugarcane yield, the simultaneous application treatment of the tested bacteria along with the application of 100% recommended phosphorus and nitrogen for sugarcane, Compared to the control treatment