Synergistic effects of poultry manure and 2,4-epibrassinolide on soil properties and performance of groundnut in the rainforest of Nigeria

The growth and yield response of groundnut (Arachis hypogaea L.) to fertilizer and other crop management inputs on Nigerian soils derived from coastal plain sands has been little studied. This greenhouse evaluation was aimed to determine the impact of chicken manure (CM) and 2,4-epibrassinolide (BR) on the growth and yield of groundnut. Four levels of CM: 0, 5, 10 and 15 tons/ha denoted as CM0, CM3, CM2 and CM1, respectively were factorially applied with two levels of foliar-sprayed BR [with: BR1= 100 and 150 mL, and without: BR0= 0 mL (control)], and arranged into a completely randomized design with three replications. The growth and yield attributes of groundnut were significantly improved across CM + BR combination, irrespective of CM levels. Plants grown in 15 tons/ha CM amended soil and sprayed with BR flowered earlier [29 days after sowing (DAS)] than the control (CM0BR0) (46 DAS). Light interception was significantly higher in treatment CM1BR1 relative to the other treatment combinations across the sampling periods. The combined 15 tons/ha CM and 250 mL BR treatment significantly produced the highest number of branches (8), pods (19), mean pod weight (36.20 g/plant), shoot dry weight (43.59 g/plant), 100-seed weight (26.10 g) and seed yield (9.84 g/plant). This treatment combination has potential to maximize groundnut yield in Calabar environs, but this is subject to field validation in subsequent trials.