This research study was carried out to investigate the effect of Jatropha curcas plant on the growth and yield of Arable crops (maize and vegetable) at Forestry Research Institute of Nigeria (FRIN) Arboretum, Jericho, Ibadan. This research study involves six (6) experimental plots of Jatropha curcas interplanted with vegetable and maize in both Mono and Agro-forestry plot respectively. Relative comparison in Jatropha curcas plant agronomic parameter such as plant height, stem girth and number of leaves, planted in Mono and Agro-forestry plots were determined and analysed using factorial experimental design in Randomised Completely Block Design (RCBD). The result of analysis of variance conducted shows significant difference in the major treatments and weeks on the parameter assessed while non existence of significant difference was recorded in the combination factor of treatment and weeks. The mean results of the parameters for plant height, stem girth, number of leaves were assessed 4.560g, 4.515g, 3.725g for maize and 127g, 96g, 72g for vegetable plant. Based on the agronomic result obtained in this study can therefore be concluded that Jatropha curcas plant could be successfully incorporated in both mono and agro-forestry practices to yield positive effect.