Response of Azadirachta indica (Neem) seedlings to biofertilizer compared to mineral nutrition

Abstract

Growth of Azadirachta indica (Neem) transplants was stimulated by inoculation with Plant Growth Promoting Rhizobacteria (PGPR). Results showed that significant increases in the vegetative growth, biomass and chemical constituents per seedling were observed in the seedlings inoculated with mixture of Azospirillum brasilense, Azotobacter chrococcum and Bacillus polymixa (PGPR), and received half dose from mineral nutrients (NPK). This treatment gave higher parameters, the percentages of increases as a result of using PGPR with half dose from mineral nutrition as compared to full dose, were 25, 22, 44, 21and 40% for plant height, stem diameter, root length, fresh and dry weight per seedling over the seedling which received full doses of mineral nutrition. It can be also concluded that the previous treatment (PGPR and half mineral fertilizer) exceeded the growth parameters by 75, 43, 47, 86 and 101% respectively over control. Also, the above treatment gave the highest values of NPK up take, total carbohydrate and chlorophyll content. These results suggest that the growth promoting substances provided by PGPR may enhance the growth of Azadirachta indica seedlings and consequently produce healthy seedling in short time.