International Journal of Recycling of Organic Waste in Agriculture (IJROWA) Utilizing rice-husk waste as an effective weed control mulch for Holy Basil (Ocimum sanctum ) production in a tropical environment Volume 13 (2024) IJROWA Issue 3, July 2024 2024 02 14 Utilizing rice-husk waste as an effective weed control mulch for Holy Basil (Ocimum sanctum ) production in a tropical environment 10.57647/j.ijrowa.2024.1303.32 EN Vivian Ogechi Osadebe Department of Crop Science, University of Nigeria, Nsukka, Nigeria 0000-0002-5984-2400 Uchenna Noble Ukwu Department of Crop Science, University of Nigeria, Nsukka, Nigeria 0000-0003-4683-3596 Nathaniel Dauda Department of Crop Science, University of Nigeria, Nsukka, Nigeria 0000-0001-5706-0416 Ifesinachi M Nwamba Department of Crop Science, University of Nigeria, Nsukka, Nigeria Amos Ejike Ede Department of Agricultural Education, Federal College of Education, Eha-Amufu, Nigeria Anthony I Onah Department of Pharmaceutical Microbiology, David Umahi Federal University of Health Sciences, Uburu, Nigeria Journal Article 2024 02 14 Purpose: The growing adverse effects of agrochemicals on environmental health and safety warrant an examination of ecologically safe alternatives for weed control. The objective of this study was to determine the effect of rice-husk waste on the growth performance and weed management (WM) of Ocimum sanctum. Method: In a randomized complete block design with three replications, nine weed management (WM) methods were assessed. These methods included black, red, and transparent polyethylene mulches; rice-husk; sawdust; hoe-weeding at 30 days after transplanting (DAT); a one-time application of 0.2 kg/ha Haloxyfop-P at 30 DAT; daily weeding; and no-weeding. Data were collected on weed parameters and growth attributes of Ocimum sanctum. All data were subjected to analysis of variance. Results: The use of rice-husk mulch resulted in the most significant (p<0.05) increase in plant height (41.70 cm), leaf number (206.80), branch number (50.50), stem girth (2.76 cm), and leaf yield (7.15 t/ha) of Ocimum sanctum compared to the other weed control methods. It was comparable to black polyethylene (BP) in these traits except in leaf number where BP recorded a lower value (165.00). BP mulch was significantly more effective in weed suppression as it recorded the least number of broad leaves (0.00), sedges (0.00) weed biomass (0.00), and the highest weed control efficiency (WCE) (100%) at 10 WAT. The treatments ranked BP>Daily-weeding>Hoe-weeded>Rice-husk>Haloxyfop-PEHS>Red-polyethylene>Sawdust> Transparent-polyethylene>Control in WCE at 10 WAT. Conclusion: The study revealed that rice-husk mulch was the most effective in enhancing the growth and yield attributes of Ocimum sanctum, ranking fourth in weed control efficiency (WCE) at 72.60%, following black polyethylene (BP) mulch (100%), daily-weeding (96%) and hoe-weeded (95.7%).   Highlights ·       The study revealed that black polyethylene mulch  exhibited the highest weed control efficiency exceeding 90%, and recorded complete weed suppression (11%) at 10 weeks after application. ·       Higher weed species diversity was observed  in plots subjected to hoe-weeded, rice husk mulched, and post-emergence herbicide treatments,  suggesting that weed management techniques can influence  the composition of weed flora. ·       Mulching with rice-husk significantly improved several growth parameters of  Ocimum sanctum, including leaf number, number of branches, plant height, stem girth, canopy diameter, and leaf yield,when  compared to other weed control methods. ·       Organic waste recycling practices such as use of rice-husk as mulch offer an effective, sustainable, eco-friendly, and cost-effective option for weed management in crop fields. ·       Medicinal herbs like Ocimum sanctum can be cultivated effectively using rice-husk mulch which provides advantages  such as soil moisture retention, weed suppression, and improved growth performance.