84%双氯磺草胺水分散粒剂对大豆田阔叶杂草的防效及对后茬作物的安全性

为考察84%双氯磺草胺水分散粒剂对大豆田阔叶杂草的防除效果及对后茬作物的安全性,在四川地区开展田间试验。选择25.2、37.8、50.4、75.6 g a.i./hm^284%双氯磺草胺水分散粒剂4个剂量进行杂草防除试验,选择25.2、37.8、50.4 g a.i./hm^23个剂量进行后茬安全性试验。结果表明,84%双氯磺草胺水分散粒剂作为土壤处理剂可有效防除田间主要阔叶杂草凹头苋、辣子草、铁苋菜、叶下珠,在施药46 d后,4个剂量处理总阔叶杂草的株防效在95.09%~99.69%之间,鲜质量防效均高于99%;84%双氯磺草胺水分散粒剂的推荐剂量为25.2~50.4 g a.i./hm^2。大豆田施用推荐剂量的84%双氯磺草胺水分散粒剂,对后茬蚕豆、油菜、小麦的出苗率(或存活率)、株高、生物量、分枝数(或分蘖数)和产量的影响较小,种植安全。

84%双氯磺草胺水分散粒剂对夏大豆田杂草的防效及安全性评价

为进一步验证分析84%双氯磺草胺水分散粒剂的药效,开展了对夏大豆田1年生禾本科杂草和阔叶杂草的防除效果及安全性评价研究。结果表明,大豆播后苗前喷施有效成分为35 g a.i./hm^(2)的84%双氯磺草胺水分散粒剂7 d后,田间杂草即出现萎蔫、枯亡等现象;30 d后,对常见阔叶杂草的总防效为100%,对禾本科杂草的鲜重防效均高于90%,而株防效分别为96.30%(牛筋草)、94.16%(马唐)、85.53%(狗尾草)、84.62%(小麦自生苗)、80.95%(稗);84%双氯磺草胺水分散粒剂对大豆的生长发育无不良影响,田间产量为4942.0 kg/hm^(2),较空白清水对照、480 g/L广灭灵乳油处理增产43.58%、12.37%,具有较好的推广应用前景。

Interaction of Seedling Germination, Planting Date, and Flumioxazin on Peanut Physiology under Irrigated Conditions

Diclosulam and flumioxazin applied preemergent (PRE) results in direct peanut exposure to these herbicides prior to seedling emergence. Flumioxazin has been reported to induce injury in adverse weather (i.e. cool-wet soil conditions) at crop emergence. Research at Ty Ty and Plains, Georgia evaluated the physiological effects of PRE herbicides to emerging peanut in 2018 and 2019. Peanut seed with variable germination and different planting dates were evaluated as additional factors. Peanut plant physiological measurements included electron transport (ETR), net assimilation rate (Anet), quantum yield of PSII (ΦPSII), and stomatal conductance to water vapor (GSW). Data were obtained from V3 to R1 peanut growth stages using a LiCOR 6800, along with stand counts and plant width measures. In 2018, diclosulam reduced peanut ETR when measured across multiple growing degree days (GDD) after planting, compared to the nontreated control (NTC). Flumioxazin reduced peanut ETR compared to the NTC, at several sample timings for each planting date. In 2018 and 2019 at both locations, flumioxazin impacted Anet less than ETR, but was consistently similar to/or greater than the NTC. Peanut ΦPSII responded similarly as Anet at each location and yr. GSW was variable in both years;however flumioxazin treated plants had higher GSW rates than other treated plants. Peanut stand counts, plant widths, and pod yields noted few differences compared to the physiological measures. Though some peanut plant physiological differences were noted when measured at varying GDD’s after planting with the different PRE treatments, planting date, and seed vigor, no specific trends were observed. Growers will often observe peanut injury from flumioxazin early in the season. However, it is transient and does not affect yield.

2-甲硫基-4,6-二氟嘧啶的合成研究

2-甲硫基-4,6-二氟嘧啶是合成除草剂双氯磺草胺的关键中间体,笔者以硫脲、丙二酸二乙酯、甲醇钠、硫酸二甲酯、三氯氧磷、氟化钾等为原料经四步反应合成了该化合物,并对影响反应的主要因素进行了研究。优化了反应条件,简化了操作。产品收率56%,纯度90%。

双氯磺草胺原药的液相色谱分析

[目的]建立液相色谱检测双氯磺草胺含量的方法。[方法]选用岛津Wonda Cract ODS-2色谱柱和紫外检测器,以乙腈-0.1%磷酸水溶液作为流动相,对双氯磺草胺原药进行分离和测定。[结果]双氯磺草胺线性相关系数为0.9997,变异系数为0.21%,标准偏差为0.20,平均回收率为99.95%。[结论]该方法具备快速、准确、分离效果好,适合于双氯磺草胺的定量分析要求。

除草剂双氯磺草胺的合成

[目的]研究除草剂双氯磺草胺的合成方法。[方法]以2-乙氧基-4,6-二羟基嘧啶为起始原料,经氯化、氟化、肼解、环合、转位、氧氯化,最后与2,6-二氯苯胺发生缩合反应,处理后即得目标产物双氯磺草胺。[结果]在优化反应条件下,反应总收率为55.3%(以2-乙氧基-4,6-二羟基嘧啶计),含量为98%;产物结构经HPLC-MS、1H NMR确证。[结论]该反应原料易得、条件温和、操作简便,适合在工业上推广应用。