Evaluation of the Effects of Different Sowing and Weed Control Methods on the Physiological Performance of NERICA 4 Rice Variety in Upland Ecology of Japan

Abstract

The experiment was established to determine the most yield enhancing combination of sowing method and weed control measure for the selected rice variety- NERICA 4. The experiment was conducted from March to November 2023, at the upland research field of JICA’s Tsukuba International Center (TBIC), Japan. The experiment forms part of the fulfilment for the completion of a rice research technique fellowship in the Knowledge Co-Creation Program (KCCP) organized and funded by the Japan International Cooperation Agency (JICA). It consists of two sowing methods; Drilling (S1) and Dibling (S2)) as well as three methods of weed control; Chemical Weeding only at Sowing (CW), Chemical Weeding at sowing with once Hand Weeding at 60 DAS (CWHW) and Chemical Weeding at Sowing with Twice Hand Weeding at 60 and 90 DAS (CW2HW) which were combined to form six treatments. Treatments were laid in Randomized Complete Block Design (RCBD) with three replications of eighteen (18) plots. 8.9 g/plot of pendimethalin 2% (G0-G0-SAN) was used. Amaranthaceae, Cyperaceae and Poaceae were the prevalence weeds family identified.  The treatment assigned to drilling and twice hand weeding in addition to chemical weeding at sowing (S1CW2HW) had the highest yield (3.95 tons/ha) while the treatment assigned to dibbling with the weeding control plot of only chemical weeding at sowing (S2CW) gave the lowest yield (2.5 tons/ha). There was significant difference at (P<0.05) amongst the mean yield values of all treatment combinations. However, the treatment assigned to same drilling but with once hand weeding (S1CWHW) had the highest profitability rank. This study concludes that sowing with drilling and weed management by pendimethalin and once hand weeding may be productively viable for the variety. This outcome may serve as a benchmark for further research within same thematic framework for increased productivity of rice farmers in the west African sub-region from where the first two authors were sent for the experiment in Japan.