文摘
Experiments were conducted to assess the control of Echinochloa oryzoides and Echinochloa phyllopogon with rimsulfuron, nicosulfuron, and foramsulfuron applied alone or simultaneously with selected broadleaf herbicides (i.e. dicamba, MCPA, sulcotrione, and mesotrione) used in maize. In pot experiments, rimsulfuron (at 12.5?g ai/ha), nicosulfuron (at 40?g ai/ha), and foramsulfuron (at 45?g ai/ha) applied at the three- to four-leaf growth stage provided on average 88, 94, and 82 % control of E.?oryzoides and 81, 88, and 76 % control of E.?phyllopogon, respectively. The average control provided by rimsulfuron, nicosulfuron, and foramsulfuron at the four- to five-leaf growth stage was 76, 81, and 71 % of E.?oryzoides and 66, 82, and 62 % of E.?phyllopogon, respectively. Greatest control of both species at any growth stage was observed with nicosulfuron followed by the highest dose of rimsulfuron or the highest dose of foramsulfuron. Co-application of dicamba or MCPA with each sulfonylurea herbicide provided lower control of both grasses at any growth stage than the sulfonylurea alone. The addition of sulcotrione to the mixtures improved the efficacy of rimsulfuron and foramsulfuron on both species at any growth stage, whereas mesotrione did not affect the efficacy of the sulfonylureas on E.?oryzoides and E.?phyllopogon in most of the cases. Field experiments with the same herbicide treatments applied at the late growth stage of the two species (beginning of tillering) showed the same behavior to that observed in the pot studies regarding the efficacy of the mixtures in most of the cases, but the reduced efficacy of the treatments pointed out the necessity of the timely application of all sulfonylurea herbicides for effective control of both species. All herbicide treatments resulted in grain yield equal to that of the weed-free control without any visible symptoms of toxicity or stunted growth on maize plants.
