EFFECTS OF APPLICATIONS OF BIOFERTILIZERS ON GROWTH AND YIELD OF MAIZE (Zea mays ) CULTIVARS

Abstract

The field experiments were conducted at the Teaching and Research Farms of Joseph Ayo Babalola University (JABU) and Federal University of Technology Akure (FUTA) in 2015 in the tropical rainforest agro-ecology of south west Nigeria. The objective was to investigate the effects of biofertilizers, viz, Azotobacter, Azospirillum and Mycohrriza on some agronomic properties of some cultivars of maize. A 4 x 3 factorial experiment was conducted consisting of four cultivars of maize and three biofertilizers laid out in Randomized Complete Block Design (RCBD). Positive effects of Azotobacter, Azospirillium and mycorriza on plant growth, biomass, development, chlorophyll content, cob diameter, nutrient composition and yield over the un-inoculated controls were recorded at the two locations. Results showed significant (P<0.05) effect of Azotobacter and Azospirillium application on vegetative growth, grain yield and development parameters in the order of Azotobacter>Azospirillium>mycorrhizal>-control. At JABU. TZEE-W with Azotobacter recorded highest grain yield (4.85 tons/ha), the highest number of leaves (13) was recorded at JABU. While the highest grain weight (366.67g) was also obtained at JABU followed by TZE-Y (346.33) with Azotobacter treatment at JABU. TZEE-Y at FUTA had the highest 1000 grain weight (343.77g) in control. The lowest 1000 grain weight (165.10g) at FUTA was obtained in TZE-Y with mycorrhizal treatment and TZE-Y at JABU (188.00g) in the control condition. Further, the results showed significant (P<0.05) effects of Azotobacter and Azospirillium application on nutrient uptake. Significant (P<0.05) effects of Azotobacter and Azospirillium applications were also observed on proximate composition of maize grains with Azotobacter inoculated maize having the highest protein content. The results of this study showed that Azotobacter was the most productive treatment while biofertilizers was the most economical treatment with respect to increasing net profit. The present study indicates that a combination of Azotobacter, Azospirillum and mycorrhizal microorganisms holds promise for the organic system of maize. Therefore in biofertilizer systems, a combination of azotobacter and free-living bacteria performed satisfactorily.