Field experiments were carried out in two locations, viz. Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai and ICAR-Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands during Kharif, 2016 and 2017 respectively to study the effect of entrapped pre-emergence oxadiargyl herbicide on the growth and yield of rice under various agro ecosystems. Weed control measures significantly reduced the density and dry weight of weeds in both the ecosystems. In mainland ecosystem, at 20 DAT, the highest reduction in weed density (61.8%) was noticed with the application of oxadiargyl encapsulated with starch which was comparable with the application of butachlor at 1.25 kg/ha on 3 DAT fb hand weeding on 40 DAT (60.8%). Whereas, under island ecosystem, the lowest total weed density (78.2%) was observed with the application of oxadiargyl loaded in zeolite which entrapped herbicides have increased sorption and decreased the dissipation of herbicide in soil which helps to release herbicide slowly through entire season for effective weed control. Application of butachlor at 1.25 kg/ha on 3 DAT fb hand weeding on 40 DAT recorded significantly higher number of productive tillers/m2 followed by the application of oxadiargyl loading with zeolite on 3 DAT. Weed free check has recorded significantly higher grain and straw yield in both ecosystems. The increase in grain yield with weed control treatment was ranged from 1.22 to 2.97 t/ha and 1.07 to 3.15 t/ha in main and island ecosystem, respectively compared to weedy check. The highest straw yield of 59.3 and 72.4% was recorded under weed free check as compared to weedy check in main and island ecosystem, respectively.