University of Guilan Cereal Research 2252-0163 10 2 2020 08 22 Evaluating the efficacy of new slow released herbicide pyrazosulfuron-ethyl + pretilachlor in weed control in transplanted rice Evaluating the efficacy of new slow released herbicide pyrazosulfuron-ethyl + pretilachlor in weed control in transplanted rice 181 192 4620 10.22124/cr.2020.16880.1607 FA Bijan Yaghoubi Assoc. Prof., Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran Hoda Abadian Assist. Prof., Deputy of Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Amol, Iran Farzin Pouramir Assist. Prof., Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran Fatemeh Mansourpour B. Sc., Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran. Journal Article 2020 06 21 The diversity of paddy weeds has led to the use of herbicide mixtures with different mechanisms of action to increase the efficacy of chemical management. The new herbicide pirazchlor (tablet 17%) is a pre-mixture of pyrazo-sulfuron-ethyl from sulfonyl-ureas with pretilachlor from chloro-acetamides which has been introduced in the form of slow released 5 g tablets to control weeds in transplanted rice. In this study, the efficacy of 191, 383, 574 and 765 g ai.ha-1 (g active ingredient per ha) pirazchlor in comparison with the common herbicides, pretilachlor (EC 50%, 750 g ai.ha-1) + bensulfuron methyl (bensulfuron, DF 60%, 35 g ai.ha-1), thiobencarb (EC 50%, 2500 g ai.ha-1) + bensulfuron, triafamone + ethoxysulfuron (council, WG 30%, 30 g ai.ha-1), along with two check treatments (without control and hand weeded control) were investigated on weed control and rice yield. The experiment was carried out in randomized complete block design with three replications in research fields of Rice Research Institute of Iran (RRII) in Guilan and Mazandaran provinces, Iran, in 2018. The results showed that weeds control and rice yield were affected by treatment, location and treatment × location interaction. In Mazandaran, biomass and density of weeds was about one-tenth of Guilan and the efficacy of all herbicides was ≥95%. In Guilan, the efficacy of herbicides in reducing the density of Echinochloa crus galli (≥88%) was higher than that of Bolboschoenus planiculmis (51-97%). The efficacy of pirazchlor at doses of 383 g ai.ha-1 or above was similar to or better than the common herbicides. Grain yield loss (economic damage of weeds) in the check treatment of without weed control in Mazandaran and Guilan was 25% and 78%, respectively, compared to hand weeded control. The highest paddy yield in Guilan and Mazandaran was 4450 and 5001 kg.ha-1, which were obtained in doses of 765 and 363 (g ai.ha-1), respectively, and were similar to or more than the common herbicide treatments and about 10% more than the hand weeded control. The diversity of paddy weeds has led to the use of herbicide mixtures with different mechanisms of action to increase the efficacy of chemical management. The new herbicide pirazchlor (tablet 17%) is a pre-mixture of pyrazo-sulfuron-ethyl from sulfonyl-ureas with pretilachlor from chloro-acetamides which has been introduced in the form of slow released 5 g tablets to control weeds in transplanted rice. In this study, the efficacy of 191, 383, 574 and 765 g ai.ha-1 (g active ingredient per ha) pirazchlor in comparison with the common herbicides, pretilachlor (EC 50%, 750 g ai.ha-1) + bensulfuron methyl (bensulfuron, DF 60%, 35 g ai.ha-1), thiobencarb (EC 50%, 2500 g ai.ha-1) + bensulfuron, triafamone + ethoxysulfuron (council, WG 30%, 30 g ai.ha-1), along with two check treatments (without control and hand weeded control) were investigated on weed control and rice yield. The experiment was carried out in randomized complete block design with three replications in research fields of Rice Research Institute of Iran (RRII) in Guilan and Mazandaran provinces, Iran, in 2018. The results showed that weeds control and rice yield were affected by treatment, location and treatment × location interaction. In Mazandaran, biomass and density of weeds was about one-tenth of Guilan and the efficacy of all herbicides was ≥95%. In Guilan, the efficacy of herbicides in reducing the density of Echinochloa crus galli (≥88%) was higher than that of Bolboschoenus planiculmis (51-97%). The efficacy of pirazchlor at doses of 383 g ai.ha-1 or above was similar to or better than the common herbicides. Grain yield loss (economic damage of weeds) in the check treatment of without weed control in Mazandaran and Guilan was 25% and 78%, respectively, compared to hand weeded control. The highest paddy yield in Guilan and Mazandaran was 4450 and 5001 kg.ha-1, which were obtained in doses of 765 and 363 (g ai.ha-1), respectively, and were similar to or more than the common herbicide treatments and about 10% more than the hand weeded control.

https://cr.guilan.ac.ir/article_4620_317527292fe744838edf7d85522682e9.pdf