阿灭净在菠萝与土壤中的残留及消解动态研究

采用气相色谱(GC-NPD)分析技术测定除草剂阿灭净在菠萝与土壤中的残留及消解动态结果表明,GC-NPD方法的最小检出量为0.0232ng,菠萝及土壤的最小检出浓度分别为0.002mg/kg和0.005mg/kg,GC-NPD方法回收率分别为87.23%~92.10%和88.80%~93.77%。喷施阿灭净80%WP4800g(a.i/)hm2,处理检测出菠萝与土壤中原始沉积量分别为0.1448~0.1646mg/kg和3.3318~3.5536mg/kg,消解半衰期分别为29.17~29.45d和25.75~30.68d,按阿灭净用量4800g(a.i/)hm2施药菠萝1次,间隔期为10d,菠萝果实残留量2年分别为0.1646mg/kg和0.1448mg/kg,参照欧共体的MRL值0.2mg/kg,按上述阿灭净剂量方法施用菠萝是安全的。     

55%2甲4氯异辛酯·莠灭净乳油的研制及其田间药效

[目的]为研制更高效、安全的新型蔗田除草混剂提供试验基础。[方法]通过盆栽试验,采用共毒系数（CTC）法评价2甲4氯异辛酯与莠灭净对马唐、青葙的联合作用。[结果]2甲4氯异辛酯与莠灭净按有效成分9∶5比例混配,对马唐和青葙的协同增效作用明显,共毒系数分别达到156.24和140.40。采用比例法和对分法,确定了2甲4氯异辛酯.莠灭净混剂中各成分的最佳配比为：2甲4氯异辛酯35.4%,莠灭净19.6%,乳化剂10.0%,其余为溶剂。经稳定性试验,该乳油各项指标符合农药乳油标准。田间试验结果表明,55%2甲4氯异辛酯.莠灭净乳油在1 073-2 310 g（a.i.）/hm^2的剂量范围内可有效防除绝大多数蔗田杂草。[结论]成功开发了高含量的莠灭净和2甲4氯异辛酯混剂产品,该产品具有高效、广谱、经济性好、使用方便等特点。     

三氟啶磺隆钠盐与莠灭净混用的联合作用

[目的]探讨三氟啶磺隆钠盐与莠灭净混用后的联合作用。[方法]以稗草、胜红蓟为供试材料,在温室盆栽条件下,采用Cowing法评价三氟啶磺隆钠盐与莠灭净混用后对稗草、胜红蓟的联合作用。[结果]三氟啶磺隆钠盐与莠灭净对稗草和胜红蓟的防治效果均随各自用药量的增加而提高,混用后的防效较各自单剂的防效大幅度提高。二者混用后对稗草的联合作用基本属于增效作用。对胜红蓟属于相加作用。[结论]二者混用用于甘蔗田除草,可以优势互补,减少各自的用量,降低三氟啶磺隆钠盐的使用成本和药害,扩大杀草谱,具有广阔的市场前景。该研究为三氟啶磺隆钠盐与莠灭净合理混用提供了科学依据。     

敌磺钠解除莠灭净对甘蔗药害的研究

为探讨敌磺纳是否能够解除莠灭净喷施在蔗苗上产生的药害,选用敌磺纳、DA-6胺鲜脂和赤霉素等3种药物,并以3个不同浓度药液,对不同受害程度的蔗苗进行解毒处理对比试验,调查蔗苗恢复情况和产量。结果表明,各处理的蔗苗恢复率、株高和产量,DA-6胺鲜脂赤霉素敌磺纳,虽然随药液浓度增加而略有提高,与对照2(清水处理)比较,恢复株数增加3.2-3.6%,甘蔗株高增加6.5%-8.0%,增产2.9%-6.7%。与对照1(不喷施莠灭净处理)比较,死苗率达43.1%-60.4%,减产55.5%-56.9%;敌磺纳、DA-6胺鲜脂和赤霉素等药剂,不能解除植物体内的药害。建议在除草过程中尽量避免药液喷施在蔗苗上,以减少对蔗苗的药害。     

乙氧氟草醚与莠灭净混剂防治玉米田杂草的室内活性配方筛选

[目的]探讨乙氧氟草醚和莠灭净复配应用于玉米田杂草防治的最佳配比。[方法]采用盆栽法研究乙氧氟草醚、莠灭净的单剂和混剂对玉米田杂草的防治效果。[结果]5个配比的共毒系数在85.06~128.63,其中1∶4.8、1∶5.4、1∶6.0、1∶7.2这4个配比的共毒系数分别为85.06、94.78、110.52和115.53,为相加作用;1∶6.6配比的共毒系数为128.63,为增效作用。[结论]建议选取制剂乙氧氟草醚∶莠灭净=1∶6.6,采用1 200~1 440 g/hm2用液量进行田间小区试验,验证其田间防效。     

莠灭净80%可湿性粉剂在玉米和土壤中残留行为研究

通过田间试验方法和气相色谱分析技术,研究了莠灭净在玉米植株和土壤中的残留行为。结果表明,莠灭净在玉米植株和土壤中的降解符合动力学一级反应方程C=C0e-KT,其半衰期在玉米植株为11.1～12.7d,在土壤中为35.1～45.8d。莠灭净80%可湿性粉剂,用药量2 100g.hm-2(1 680 g.hm-2有效成分),于玉米苗后3.5叶期施药,茎叶喷雾1次,85 d后收获玉米植株和玉米粒中莠灭净最终残留量均小于0.01 mg.kg-1,参考美国规定莠灭净在玉米上最大残留限量标准0.25 mg.kg-1,按此推荐使用剂量是安全的。     

Herbicide ready-mixes effects on weed control efficacy,non-target and residual toxicities,productivity and profitability in sugarcane–green gram cropping system

Weeds pose a major challenge at the initial stages of sugarcane and when uncontrolled cause high yield losses. This study was undertaken to define a better and cost-effective weed management strategy. We compared ametryn + trifloxysulfuron-sodium (hereafter referred to as trifloxysulfuron) ready-mixes with single applications of trifloxysulfuron, atrazine and 2,4-D for efficacy, non-target and residual toxicities, yield and profitability in a sugarcane–green gram rotation. Results showed that a density of 100 weeds m^?2 could reduce sugarcane yield by 18.4 t ha^?1. The ready-mix ametryn + trifloxysulfuron (1097.3 + 27.8) g a.i. ha^?1 applied 15 days after planting (DAP) caused reductions in weed density by 88.2%, 90.9%, and 90.3%, and weed biomass by 68.0%, 53.8%, and 56.2% compared to unweeded control at 30, 60, and 90 DAP, respectively. Consequently, the sugarcane yield, system productivity, and net returns were increased by 92.1%, 43.5%, and 1515%, respectively due to this ready-mix. It increased system productivity by 23%, 17.2%, and 22.7% compared to trifloxysulfuron, atrazine, and 2,4-D treatments, respectively. This ready-mix may be recommended in sugarcane. This would reduce weed seed bank and herbicide application cost by 50%, and prevent/delay weed shift and resistance.