ABSTRACT:

Field trials wereconductedduring 2018 and 2019rainy seasons on the research farm of the Institute for o o Agricultural Research (IAR), Ahmadu Bello University Samaru, Zaria (11 11ꞌN, 07 38ꞌE 686m above sea level) in the Northern Guinea Savanna ecological zone of Nigeria.The experiment was carried out to evaluate growth characters and paddy yield of upland rice (Oryza sativa L.) as influenced by weed management strategies, source and rate of biochar. The treatments consisted of three different weed management strategies [chemical weed control (Saflufenacil + Dimethenamid-P at 0.5 kg a.i/ha applied preemergence), integrated weed control method (Saflufenacil + Dimethenamid-P at 0.5 kg a.i/ha applied preemergence + one hand weeding at 9 WAS) and cultural weed control method (Hand weeding at 3, 6 and 9 WAS) which is the farmers’ practice], three sources of biochar organic biomass (rice husk, groundnut shell -1 and wood shavings) andthree rates of the biochar (0, 2 and 4 t ha ). All the treatments were laid out in a SplitPlot Design and replicated three times. The three rates of biochar and three different weed management strategies were factorially combined and laid out as the main plot treatment. The sub-plot treatments consisted of the three sources of biochar. The application of Saflufenacil + Dimethenamid-P at 0.5 kg a.i/ha + one hand weeding at 9 WAS effectively controlled weedsand enhanced performance of plant height, leaf area index and crop growth ratewhichsignificantly increased paddy yield than other weed control methods. -1 Theincorporation of rice husk biochar at 2 t ha gave highestperformance forgrowth attributesand the resultant paddy yieldthan other sources and rates of biochar.The results showed that application of Saflufenacil + Dimethenamid-P at 0.5 kg a.i/ha + one hand weeding at 9 WAS in combination with rice -1 husk biochar at 2 t ha is most appropriate for enhancing growth and increasing paddy yield of upland rice at Samaru in the Northern Guinea Savanna ecological zone of Nigeria.