Response of groundnut to thermal indices as influenced by intercropping and mulching in tropical wet and dry climate in Nigeria
Temperature as a limiting factor to groundnut production had affected groundnut economic value in a tropical wet and dry climate of Nigeria. A field trial was carried out to evaluate the effect of mulching on some selected thermal indices of groundnut intercropped with maize at Abeokuta during the early 2018 cropping season. The experiment was arranged in 6×3 factorial and laid out in a randomized complete block design with three replicates. Experimental factors were the cropping system of sole planting of three groundnut cultivars SAMNUT-24 (GNUT1), SAMNUT-25 (GNUT2), SAMNUT-26 (GNUT3) and their intercrop combinations with maize (SAMMAZ-15), mulching methods were black polythene, white polythene and banana leaf. Thermal indices were estimated on emergence, flowering, pod formation, seed formation, and maturity phases. The results of thermal indices showed that intercrop significantly influence (p≤0.05) growing degree days (GDD) of groundnut at emergence (2225.50 ºday) and flowering (2700.96 0day) phases and mulching was significant (p≤0.05) at seed formation phase. In conclusion, intercrop showed significant influence on thermal indices and yield of groundnut, white polythene mulch enhanced heat accumulation at emergence, flowering and seed formation stages.