典型药剂对不同留茬高度加拿大一枝黄花的防效

于2018年7月25日-9月20日选用5种典型药剂与2种助剂对长沙县郭公渡成片发生区旺盛期加拿大一枝黄花进行了物理法联合化学法防除的田间试验。结果表明,割除保留10 cm茬23 d后喷施41%草甘膦异丙胺盐AS 1 097.40 g/hm~2+农用有机硅增效剂600.00 g/hm~2、48%三氯吡氧乙酸丁氧基乙酯EC 900.48 g/hm~2+20%草铵膦AS 489.60 g/hm~2、25%环嗪酮SL 687.50 g/hm~2+20%草铵膦AS 629.40 g/hm~2与割除保留20 cm茬23 d后喷施25%环嗪酮SL 687.50 g/hm~2+农用有机硅增效剂600.00 g/hm~2、25%环嗪酮SL 687.50 g/hm~2+乙基化和甲基化植物油1 800.00 g/hm~2对加拿大一枝黄花的防效最佳,施药后34 d株防效均达到100%,地上与地下鲜重防效分别在78%、75%以上,且完全根腐,用药剂量也少。而30组药剂中除41%草甘膦异丙胺盐AS 1 097.40 g/hm~2、20%氯氟吡氧乙酸EC 60.00 g/hm~2+20%草铵膦AS 419.80 g/hm~2、48%三氯吡氧乙酸丁氧基乙酯EC 900.48 g/hm~2+20%草铵膦AS 489.60 g/hm~2三组低剂量药剂处理外,其他药剂的低剂量处理对留茬30、40、50 cm加拿大一枝黄花的防除均不能达到根腐。相关性分析结果表明,施药天数、施药剂量与施药后样方内腐烂株数呈正相关,而与施药后样方内植株平均地上、地下鲜重均呈负相关。

Control efficacy of typical herbicide on Solidagocanadensis with different stubble heights

From July 25 to September 20, 2018, five typical herbicides and two adjuvants were used to control Solidago canadensis L. in Guogongdu, Changsha county, where the outbreak occurred in the middle and late stage. The results showed that when S.canadensis was cut to leave 10 cm stubble for 23 d, glyphosate-isopropylammonium 41% AS 1 097.40 g/hm2+organosilicon 600.00 g/hm2, triclopyr-butotyl 48% EC 900.48 g/hm2+glufosinate ammonium 20% AS 489.60 g/hm2 and hexazinone 25% SL 687.50 g/hm2+glufosinate ammonium 20% AS 629.40 g/hm2 demonstrated the best control efficacy. When 20 cm stubble was retained, hexazinone 25% SL 687.50 g/hm2+organosilicon 600.00 g/hm2 and hexazinone 25% SL 687.50 g/hm2+ethyl and methylated vegetable oil 1 800.00 g/hm2 showed the best control efficacy. After treatment for 34 days, all the plant control efficacy reached 100%. The fresh weight control efficacies aboveground and underground were 78% and 75%, respectively. The above herbicides could make S.canadensis root rot completely, and the dosage is low. While for the low dose treatments of 30 herbicides on S.canadensis with stubble height of 30 cm, 40 cm and 50 cm, only glyphosate-isopropylammonium 41% AS 1 097.40 g/hm2, fluroxypyr 20% EC 60.00 g/hm2+glufosinate ammonium 20% AS 419.80 g/hm2 and triclopyr-butotyl 48% EC 900.48 g/hm2+glufosinate ammonium 20% AS 489.60 g/hm2 could achieve complete root rot. Correlation analysis showed that days and dosage were positively correlated with the number of rotten plants in the quadrat after spraying herbicides and negatively correlated with the average aboveground and underground fresh weight of plants in the quadrat after spraying herbicides.