Optimizing Rhizobium spp. Application for Maximizing Peanut Yield in the Sudanian Climate of Chad

Peanut is one of the cash crops in Chad. The impoverishment of agricultural soils in recent years has contributed to its decline in production. The objective of this study is to improve peanut production by introducing microbial biofertilizer (Rhizobium spp.). More specifically, it is to determine the optimal dose of Rhizobium spp. on peanut crops. The experiment was conducted at the experimental site of the University of Sarh (Chad). The peanut variety Fleur 11 with a 90 day cycle was grown in a Fisher block design with six treatments and 4 replicates. Treatments T0, T1R, T2R, T3R, T4R, T5E represent respectively the negative control without Rhizobium spp. and without fertilizer, the dose of Rhizobium spp. 3.12 g/ 1 kg of seed, 6.24 g/ 1 kg of seed, 9.36 g/ 1 kg of seed, 12.48 g/1 kg of seed and the 2nd positive control with mineral fertilizer (20-10-10). Treatment T5E (41.825±1.456) recorded the highest number of leaves at 30 DAS followed by T0 (31.475±2.652). T3R (90.725 ±3.397) obtained the highest number of leaves at 45 DAS followed by T5E (79.85±5.424). T3R (112±2.497) recorded the highest number of leaves at 60 DAS followed by T5E (101.05 ±3.426). T3R (3.503 kg/20 m2 ±0.338) recorded the highest shell yield followed by T5E (3.238 kg/20 m2 ±0.577). T3R (515 g ±8.793) recorded the highest 1000 seed weight followed by T5E (509.75 g ±9.322). The introduction of Rhizobium spp., at a dose of 9.36 g per 1kg of peanut seed, resulted in better performance in terms of good vegetative development and pod yield. However microbial biofertilizers (Rhizobuim spp.) have a late action compared to other fertilizers. Therefore a good fertilization with Rhizobium spp. on peanut crops could be preceded by organic fertilization during ploughing to ensure a good start to the vegetative cycle. In this case, further studies are necessary to confirm the results obtained under the same experimental conditions and also to determine the quantity of organic fertilizer to be applied during ploughing.