Effect of spray volume, water quality, adjuvants and ammonium salts on sethoxydim activity

[摘要] The effects of spray carrier, pH, adjuvants and ammonium salts, environmental factors,and spray volume on sethoxydim {2-[ 1-ethoxyirnino-butyl]-5-[2-( etylthio )propyl]-3-hydroxy-2-cyclohexen-1-one} activity in a glasshouse on tomato (Lycopersicumesculentum L cv. Star 9001) and oats (Avena sativa L cv. SSH 241) were studied.Sodium bicarbonate, potassium carbonate and spray solution pH were antagonistic tosethoxydim phytotoxicity. Spray solution pH and ions present were antagonistic tosethoxydim phytotoxicity only when the spray carrier pH exceeded 6.5.Sadol and ammonium salts (ammonium nitrate and ammoruum sulfate) were equallyeffective in enhancing sethoxydim activity regardless of the presence of antagonistic salts.Bladbuff 5 was moderately effective in the enhancement of sethoxydim phytotoxicity onlywhen sethoxydim was applied at 186.0 g ai.ha¹ and not at 139.5. Addition of Agral 90and Break- Thru were not beneficial, or were both of little value as adjuvants withsethoxydim.Sethoxydim applications at temperatures ranging between 25 and 35°C were equally moreeffective as compared to 15°C. However, Sadol, Break- Thru and ammonium salts weremost effective in enhancing sethoxydim performance at 25°C than at 15 or 35°C.When averaged across sethoxydim rates and the presence of sodium bicarbonate and inpotassium carbonate in the spray solution, oat fresh top mass reduction increased ascarrier volume was decreased from 875 to 175 l.ha¹.In all the experiments conducted, tomato plants did not show any injury to negativegrowth suggesting that sethoxydim may be considered for control of grass weeds intomatoes.

[发布机构] University of the Free State