Effect of Weeding Regime and Row Direction on Growth and Yield of Upland Rice in Uganda

A study determined the effects of row direction and integrated weed management on the growth, productivity and economics of upland rice at Ikulwe Research Station using a completely randomized block design, replicated thrice with NAMCHE 5 upland rice in Uganda (2021b & 2022b). 12 treatments with 6 weeding regimes namely Pre- emergence Butanil (PREB) + 1hand hoeing (HH), 2HH, 3HH, PREB + Post emergence Butanil (POEB), weekly weeding (42 days) and control (EW & NS orientation) were adopted. Nitrogen (100 kg) Phosphorus (60 kg) and Potash (40 kg) were applied ha-1. Collected data on plant height, tillers, leaves, panicles; and grains were subjected to ANOVA (13th edition Genstat). Higher growth and yield parameters were in EW than NS direction. Leaves (27-28 leaves), height (65-70 cm), tillers (5-6 tillers and panicles (4-5 panicles) plant-1 were high under 2HH, PREB +1HH, PREB + POEB and 3HH (EW) compared to similar treatments in NS direction during 2021b and 2022b. Grain yield (2.34 t ha-1; HH), (2.26 t ha-1; PREB + 1 HH), (2.01 t ha-1; PREB + POEB), (1.89 t ha-1; 3HH) was significantly high in 2021b. During 2022b increased panicles (4-5 panicles), panicle length (21 cm), grains panicle-1 (110-117 grains) and grain yield (3.8 - 4.4 t ha-1) were recorded relative to 2021b. Weekly weeding (EW) developed high grains panicle-1 (102 grains) and grain yield (3.0 t ha-1) in 2022b relative to reduced tillers (4.5 tillers), filled panicles (3.6 panicles) and grain yield (1.9 t ha-1) in 2021b. Row directions had no effect on leaf width and grass biomass was numerically higher under EW than NS direction. Benefit Cost Ratios and Marginal Rate of Returns were optimum under 2HH and PREB + 1HH (EW). 2HH and PREB + 1HH (EW) may be recommended in Uganda having been the most economic technologies.