Evaluation of Rhizobial Inoculants for Symbiotic Performance of Faba bean (Vicia faba L.) in the Arsi Zone, Southeastern Highlands of Ethiopia

Abstract

This study was initiated to evaluate the effect of locally isolated Rhizobium inoculants on nodulation and yield of faba bean at Arsi Zone, Ethiopia for two consecutive years. Eight treatments comprising six effective isolates of rhizobia, un-inoculated (negative control), and recommended N-fertilized (18kg N ha^-1) were laid out in a randomized complete block design with three replications. The result of the experiment indicated that all inoculation treatments increased nodule number, nodule dry weight, and nodule fresh weight, yield, and yield components over the control check in all experimental sites. The result, however, showed the non-significant (p < 0.05) effect of Rhizobium inoculation on 100 seed weight in all Experimental sites as compared to each treatment. Inoculating FB-24 and FB-120 gave the highest mean grain yield (4273.4 kg ha^-1 and 4192.2 kg ha^-1) respectively. These records were 61 and 58% over the un-inoculated treatment respectively. In all experimental sites, FB-24 and FB-120 inoculation resulted in the highest nodulation and grain yield production as compared to the other treatments. In general, isolates from the Arsi zone showed good performance in all yield and yield parameters Therefore, FB-24 and FB -120 were recommended as candidate isolates for faba bean biofertilizer production in the Arsi Zone of Ethiopia.