Evaluation of Pre and Post Emergence Herbicides Efficacy on Upland rice (Oryza sativa L.) Weeds in Fogera Hub, Ethiopia

Abstract

Rice (Oryzae sativa L.) is by far the most important stable food crop for over half of the world population for both developing and developed nations, where its consumption has increased considerably due to food diversification and its calorie demand. However, its productivity and quality are highly limited by the occurrence of diseases, insect pests and high weed infestations. Weeds can reduce rice yield by over 30% and this makes farmers to incur 70% of their cost to manage it because of the availability of ample moisture with in the rice field and long period of infestation. The objective of this study was aimed to evaluate the efficacy of broadleaf and grass weed targeted herbicides of upland rice and recommend the most effective ones. An experiment was conducted at Fogera National Rice Research and Training Center experimental station for two consecutive years (2017-2019) using NERICA 4 Variety. It was carried out in aerobic soil condition. Eight treatments, two pre-emergences (S-metolachlor 290 g/l + atrazine 370 g/l and S-metolachlor 960 g/l) herbicides, four post-emergence herbicides (Bispyribac-sodium 10% SC, Pyroxsulam45 g/l, Lodosulfuron-methyl-sodium 7.5g/l+ Mesosulfuron methyl 7.5 g/l and 2,4-D dichlorophenoxy acetic acid 720 g/l acid), two times manual weeding and control check (weedy check) were used for evaluation. The treatments were arranged in randomized complete block design with three replications. Weed population and agronomic parameters data were recorded. The result revealed that post-emergence herbicides were highly effective over pre-emergence herbicides to manage upland rice weeds. Two times of manual hand weeding followed by Bispyribac-sodium 10% EC and Pyroxsulam45 g/l herbicides treatments gave high grain yield (3243.4 and 3063.6 kg ha-1), respectively. Therefore, it can be concluded that Bispyribac-sodium 10% EC could be recommended for upland weeds management followed by Pyroxsulam45 g/l herbicide with integration of other management practices.