Effects of Planting Methods and Seed Density on Vegetable Yield and Nutrient Composition of Solanum macrocarpon and Solanum scabrum in Southwest Nigeria

Abstract

Two field studies were carried out using Solanum macrocarpon and Solanum scabrum to investigate the effects of planting methods and seed density required for optimum biomass yield and nutrient content in southwest Nigeria. Two planting methods (drilling and broadcasting), and two seed densities (4 and 8 table spoon full) were investigated as a 2 × 2 × 3 factorial experiment in randomized complete block design and replicated three times. Four seed spoons gave 25.78 kg seeds ha−1 for S. macrocarpon and 20.67 kg·seeds·ha−1 for S. scabrum. Significant highest S. macrocarpon shoots (2.75 kg·m−2) and Ca, K, Fe and Zn contents and S. scabrum (2.95 kg·m−2) and Zn content, were obtained with drilling and four spoons of seeds compared with broadcasting and 8 spoons of seeds. This treatment gave average values for N, P, K, Mg, Ca, Na, Fe, Zn, Mn, Cu, Ca/P and Na/K ratio were 2.79%, 0.03%, 3.37%, 1.64%, 0.02%, 300 mg·kg−1, 100 mg·kg−1, 300 mg·kg−1, 8 mg·kg−1, 1.22 and 0.008 for S. macrocarpon and 2.05%, 0.27%, 5.81%, 3.27%, 2.91%, 0.09%, 280 mg·kg−1, 52.99 mg·kg−1, 359.35 mg·kg−1 and 22.42 mg·kg−1, 11.63 and 0.016 for S. scabrum. It was concluded that planting in drilling made weeding, fertilizer application, irrigation and harvesting more effective rather than by broadcasting, and four spoons of seeds per 9 m−2 produced deep green and broader leaves and balanced nutrient contents than eight spoons of seeds.