Abstract

In this regard, a field study was conducted during 2016–17 at Khuzestan University of Agriculture and Natural Resources in collaboration with Sugarcane Agro-industry of Dehkhoda, Ahvaz, Southwest Iran to investigate the effect of Enterobacter cloacae and Pseudomonas putida growth-promoting rhizobacteria under different levels of nitrogen and phosphorus on quantitative and qualitative yield of sugarcane. The experiment was laid out under split-block design with 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) on CP73–21 as sugarcane test variety. Results revealed that the treatment of simultaneous application of growth-promoting bacteria 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), in the case of quantitative traits including stalk yield, height, diameter, stalk density, percentage of nitrogen and phosphorus of sugarcane leaves were 96.9%, 98.1%, 95.7%, 96.3%, 100.2% and 101.9% success, respectively and also, in comparison with the control treatment, the mentioned treatment achieved success in the case of qualitative traits including, brix %, CCS% and sugar yield of sugarcane, 95.29, 99.24 and 98%, respectively. Also, regarding the characteristics of sugarcane yield and sugar yield, the simultaneous application treatment of the tested bacteria along with the application of 100% recommended phosphorus and nitrogen for sugarcane was 110.15 and 116% successful compared to the control treatment, respectively, and sugarcane yield and sugar yield Per unit area increased by 10.15 and 16%, respectively. Therefore, the strategy of combined use of growth-promoting bacteria in sugarcane, along with 75% nitrogen and phosphorus recommended for it, both maintained the yield of sugarcane and sugar at an optimal level and saved 25% in nitrogen and phosphorus consumption, and this issue reduced the cost of sugarcane production.