Reference

Selection of a rice herbicide from several sulfonylureas

Selection of a rice herbicide from several sulfonylureas. Takeda, Shunji; Yuyama, Takeshi; Ackerson, Robert C.; Weigel, Russell C.Chemicals with cas numbers 64902-72-3 and 74223-00-0 also play role. (Agrichem. Div., Du Pont Japan, Ushiku 300-12, Japan). Zasso Kenkyu, 30(4), 278-83 (Japanese) 1985. CODEN: ZASKAN. ISSN: 0372-798X. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) Seven sulfonylurea herbicides, DPX-W4515 [64901-63-9], DPX-T6375 [74223-00-0], Chlorsulfuron [64902-72-3], metsulfuron-methyl [74223-64-6], DPX-F5390 [83055-96-3], DPX-F5384 (I) [83055-99-6] and DPX-R5582 [73747-81-6], were tested for their herbicidal activity in rice as a function of their structure. Both I and DPX-T6375 which have substituents of 2-CO2Me were tested in Petri dishes to examine their effect during early growth of rice, Brassica pekinensis and Sagittaria pygmaea; I had the highest selectivity between rice and other plants and DPX-T6375 provided little selectivity. DPX-W4515, DPX-T6375, DPX-W4189 and DPX-T6376, all with Ph moiety, exhibited very high weed control activity, but caused severe phytotoxicity on transplanted rice exhibiting little selectivity between rice and weeds. I, with 2-CO2Me substituted benzyl moiety, was highly active; 2-Cl-substituted DPX-F5390 had very low activity and 2-Cl-substituted phenoxy (DPX-R5582) had considerable activity. Among these sulfonylureas, I had sufficient crop safety for rice. .

Safening of DPX-F5384 on rice by combination with thiocarbamate herbicides

Safening of DPX-F5384 on rice by combination with thiocarbamate herbicides. Yuyama, Takeshi; Sweetser, Philip B.; Ackerson, Robert C.; Takeda, Shunji (Agric. Prod. Div., Du Pont Japan, Tokyo, Japan). Zasso Kenkyu, 31(2), 164-70 (English) 1986. CODEN: ZASKAN. ISSN: 0372-798X. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) Rice plants transplanted onto a clay loam soil with a low humus content were injured by treatment of the soil with DPX-F5384 (I) [83055-99-6] at 100 g/ha. The injury was reduced by simultaneous application of thiobencarb (II) [28249-77-6], MY-93 (III) [61432-55-1], CH-83 [3134-70-1], or SC-2957 [85785-20-2] at 2100-3000 g/ha, but not by molinate. Simultaneous applications of II at 1000-3000 g/ha reduced inhibition of rice leaf elongation caused by I at 50-100 g/ha. Simultaneous application of I with II or III at 50-75, 2100, and 3000 g/ha, resp., gave good control of barnyardgrass (Echinochloa oryzicola) and Scirpus juncoides at the 1- to 3-leaf stages. The rate of I metab. by excised rice leaves was enhanced by preliminary foliar application of II or III at 2000 g/ha to the plants. The effect of thiocarbamates in reducing phytotoxicity of I on rice was ascribed to the enhancement of I metab. by these compds.