Development of environmental friendly bioinoculate for peanut (Arachis hypogea L.) production in Eastern Ethiopia

Background: Bacterial bioinoculate is one of environmentally friendly input for crop production. Several works revealed that effectiveness of Rhizobium bioinoculant have been affected by the native rhizobia population. Hence, this study was initiated to evaluate the effect of selected Bradyrhizobium in nodulating peanut in the major growing areas of Ethiopia. Methods: The effect of eight effective Bradyrhziobium vis-a-vis 20 kg N ha−1 and the control check on the nodulation and yield of two peanut cultivars (Sedi and Werer 942) at Babile and Fedis, eastern Ethiopia, during 2013 cropping season was evaluated. Results: The results showed that the inoculation, location and cultivar and their two and three ways interaction had a significant influence on the nodulation and grain yield. Inoculation of Bradyrhizobium increased the nodule number, nodule dry weight, number of seeds per plants, total pods weight, hundred seeds weight, total biomass yield, grain yield and shelling % up to 37, 24.9, 22.4, 22.5, 5.5, 26.2, 35.8 and 24.1%, respectively. Isolate HUGNR-29 was found to be more effective as it scored the highest nodule dry weight and grain yield. Application of inorganic N increased the yield and yield components of peanut in either of locations. Though the statistically better effective nodule % was recorded at Babile, significantly higher nodule number, nodule dry weight, and total N accumulation were obtained from Fedis than Babile site. Significantly higher total pods weight, hundred seeds weight, total biomass weight, grain yield and total plant N accumulation was recorded with the cultivar werer-962 than those produced with Bati-Sedi. Conclusions: The result showed that Bradyrhizobium inoculation is essential to improve the peanut production through environmentally and economically sustainable ways though the soil native rhizobia nodulating peanut was high. Peanut cultivar and study site based rhizobia inoculant development is also important.