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.