Inhibition of germination and growth behavior of sesame under selected Agroforestry tree species in the tropical rainforest area of Nigeria

A field experiment was carried out to investigate germination and early development of sesame (Sesamum indicum L.) as inhibited by selected common tree species (Azardiracta indica, Parkia biglobosa and Vitellaria paradoxa) over a period of 10 weeks. The experiment was laid out in Randomized Complete Block Design (RCBD) with three (3) replicates. Two seeds of studied arable crops were planted on beds 3m by 3m dimension at 90cm by 30cm under each tree species while the open space was used as control. Data were collected on germination, plant height, stem diameter, number of leaves, number of branches, root length, the above grand biomass and the below grand biomass and were subjected to statistical analysis using Analysis of Variance (ANOVA) while the significant mean were separated using Duncan's Multiple Range Test (DMRT) at 5% possibility level. Neem tree (Azardiracta indica), Locust tree (Parkia biglobosa), and shear butter tree (Vitellaria paradoxa) inhibited the germination and physiological development of sesame. The statistical germination value (56.67) observed in TNS and TLS was significantly (p < 0.05) lower than 60.00 (TSS) and 100 observed in the control. Since tropical farming system is commonly characterized by an agroforestry, where certain common tree species are unavoidably co-exist with certain arable crops, the significant of the present finding is that famers are to avoid planting of the studied crop on any farm land with these agro-forestry trees.