氯吡·苯·唑草可湿性粉剂高效液相色谱分析方法研究

本文采用反相高效液相色谱法,以甲醇+水+冰乙酸为流动相,使用C18色谱柱和二极管阵列检测器,在245nm波长下对试样中的氯氟吡氧乙酸、唑草酮和苯磺隆进行分离和定量分析.结果表明氯氟吡氧乙酸、唑草酮和苯磺隆的线性相关系数分别为0.999 0、0.999 4、0.999 1;标准偏差为0.050、0.013、0.019;变异系数为0.29％、0.86％、0.53％;平均回收率为99.97％、99.93％、99.56％.     

山东省冬小麦田猪殃殃抗药性水平及ASL靶标抗性机理分析

为明确山东省冬小麦田猪殃殃Galium aparine对常规除草剂氯氟吡氧乙酸、苯磺隆及双氟磺草胺的抗性水平和抗性种群的乙酰乳酸合成酶(acetolactate synthase,ALS)靶标抗性机理,在温室内采用整株生物测定法测定21个猪殃殃种群对氯氟吡氧乙酸、苯磺隆和双氟磺草胺的抗性水平,同时根据猪殃殃ALS基因序列设计引物,提取猪殃殃高抗种群单株基因组DNA进行测序,并与拟南芥Arabidopsis thaliana敏感型ALS基因进行比对,查找突变位点分析其抗性机理。结果表明,21个猪殃殃种群对氯氟吡氧乙酸均敏感,尚未产生抗性;90.48%的猪殃殃种群已对苯磺隆产生了抗性,其中低抗、中抗和高抗种群分别占总种群数的23.81%、23.81%和42.86%,相对抗性指数最高为1 134.82;71.43%的猪殃殃种群已对双氟磺草胺产生了抗性,其中低抗、中抗和高抗种群分别占总种群数的19.05%、9.52%和38.10%,相对抗性指数最高为87.05。高抗苯磺隆种群XZ-1和LW均发生了ALS基因第197位氨基酸功能位点的突变,其中XZ-1种群发生了CCC(脯氨酸)到TCC(丝氨酸)...     

The fate of fluroxypyr in the soil in an oil palm agroecosystem

A study on the fate of fluroxypyr in Malaysian agricultural soils was carried out under natural conditions in an oil palm plantation. Three experimental plots in the oil palm estate were selected and three types of treatments were administered, namely fluroxypyr at the recommended dosage, double the recommended rate, and the untreated control. Residues of fluroxypyr in the soil, water, and oil palm leaf were monitored at regular intervals up to 90 days after treatment (DAT). The recovery of fluroxypyr in the water and soil samples ranged from 91–102% when fortified at 1–25 p.p.b. and 91–98% when fortified at 4–50 p.p.b. The recovery from the oil palm leaf ranged from 76–114% when the oil palm leaf sample was fortified at 0.05–1.0 p.p.m. The results showed that fluroxypyr leached down to 50 cm depth at 1 DAT when the plots were treated with either dosage. However, fluroxypyr was not detected in the soil residue at 14 and 21 DAT. Fluroxypyr was not detected in the oil palm leaf samples irrespective of the rates of herbicide application or sampling intervals. The residue of fluroxypyr was detected in water from a nearby stream up to 5 DAT at levels ranging from 0.06–0.21 µg L⁻¹. This result suggests that fluroxypyr persists for a short period in the soil and water ecosystems, but not in the oil palm leaf.     

几种除草剂与莲子草假隔链格孢混用防除空心莲子草的初步研究

在测定使它隆、农达、农思它、盖草能等除草剂对莲子草假隔链格孢(Nimbyaalternantherae)菌丝生长和孢子萌发抑制作用的基础上,研究了使它隆和农达与莲子草假隔链格孢混用防除空心莲子草的可能性实验结果表明:在1000倍的浓度下几种除草剂对该菌菌丝生长的相对抑制率依次为农思它(955%)>盖草能(80%)>使它隆(694%)>农达(445%);对孢子萌发则只有农思它稍有抑制作用(174%),其它3种均无抑制作用;2000倍的使它隆和农达分别与40g/L菌丝(湿重)的莲子草假隔链格孢菌丝悬浮液等量混合比单纯使用除草剂或菌丝悬浮液的除草效果好     

Control of Ailanthus altissima using cut stump and basal bark herbicide applications in an eighteenth-century fortress

The Cittadella di Alessandria (Italy) is a military fortification that was built in the 18th century. The site has recently been abandoned and is now colonised by weeds, including the invasive Ailanthus altissima. The aim of the study was to compare the efficacy of different herbicides (glyphosate, a mixture of aminopyralid + fluroxypyr and triclopyr + fluroxypyr) applied to cut stumps or to the basal bark of A. altissima. For the cut stump application, plants were first cut at the base and then immediately sprayed and for the basal bark application, the lower 50 cm of the plants was sprayed with the herbicides; untreated cut plants were used as a control, for comparison. Two runs per study were carried out (in summer 2015 and in spring 2016). Efficacy was assessed up to 2018 by counting the resprouts and their height in the cut stump application and, for the basal bark treatment, by measuring the variation in the plant circumference after treatment. The cut stump treatment carried out in summer greatly reduced the number of resprouts, compared to the spring treatment, to less than one sprout per plant when aminopyralid + fluroxypyr was used, and its efficacy lasted for about two years. The basal bark treatment did not control the species, but lower levels of variation in circumference and greater mortality were detected in plants treated with aminopyralid + fluroxypyr. Considering the high level of infestation of the site and the high risk of plant resprouting, repeated cut stump treatments with aminopyralid + fluroxypyr would be preferable to eradicate this invasive species.     

氯氟吡氧乙酸等几种麦田阔叶除草剂药效试验

当前小麦阔叶除草剂品种繁多,各种除草剂防除麦田阔叶杂草效果差异较大。氯氟吡氧乙酸等几种麦田阔叶除草剂药效试验表明:200.0g/L氯氟吡氧乙酸在施药后30d,鲜质量防效和株防效分别达到78.4%和83.0%,持效期长,杀草彻底;56%二甲四氯钠+75%苯磺隆不同用药量和用水量以56%二甲四氯钠30.0g/667m2+75%苯磺隆1.5g/667m2对水30.0kg/667m2防效最高。建议:在以猪殃殃、婆婆纳等恶性杂草为主的麦田选用200.0g/L氯氟吡氧乙酸;在以播娘蒿、荠菜、遏蓝菜等杂草为主麦田,选用56%二甲四氯钠+75%苯磺隆。另外为避免杂草产生抗药性,56%二甲四氯钠+75%苯磺隆、22%唑草酮+14%苯磺隆、40%唑草酮+10%苯磺隆可交互使用。     

Modelling interactions between herbicide dose and multiple weed species interference in crop–weed competition

The effects of a range of herbicide doses on crop–multiple weed competition were investigated. Competitivity of Galium aparine was approximately six times greater than that of Matricaria perforata with no herbicide treatment. Competitivities of both weeds decreased with increasing herbicide dose, being well described by the standard dose–response curve with the competitivity of M. perforata being more sensitive than that of G. aparine to a herbicide mixture, metsulfuron‐methyl and fluroxypyr. A combined model was then developed by incorporating the standard dose–response curve into the multivariate rectangular hyperbola competition model to describe the effects of multiple infestation of G. aparine and M. perforata and the herbicide mixture on crop yield. The model developed in this study was used to predict crop yield and to estimate the herbicide dose required to restrict crop yield loss caused by weeds to an acceptable level. At the acceptable yield loss of 5% and the weed combination of 120 M. perforata plants m^?2 and 20 G. aparine plants m^?2, the model recommends a mixture of 1.2 g a.i. ha^?1 of metsulfuron‐methyl and 120 g a.i. ha^?1 of fluroxypyr.     

氯氟吡氧乙酸在小麦及土壤中残留的分析方法

采用氢氧化钠-甲醇溶液提取,二氯甲烷萃取,定量甲醇、浓H2SO4条件下酯化,气相色谱法测定小麦及土壤中的氯氟吡氧乙酸。氯氟吡氧乙酸质量浓度在0.01~1.0 mg.L-1之间线性关系良好。在添加浓度0.01~0.8 mg.kg-1下,植株、土壤和籽粒中氯氟吡氧乙酸的平均回收率分别为72.3%~86.7%、83.6%~95.8%和77.7%~87.3%,变异系数分别为3.02%~8.59%、2.87%~8.46%和2.75%~7.61%。氯氟吡氧乙酸的最小检测量为1.0×10-11g,在植株、土壤和籽粒中最低检出浓度均为0.01 mg.kg-1。该方法的准确性、精确性和灵敏度均满足农药残留分析的要求。     

助剂对20%氯氟吡氧乙酸乳油润湿性能及对空心莲子草防效的影响

通过田间小区试验,验证了不同助剂对20%氯氟吡氧乙酸乳油(EC)防除空心莲子草的增效作用,并系统研究了不同助剂对20%氯氟吡氧乙酸EC药液在空心莲子草叶面润湿性能的影响。结果表明:添加氮酮、油酸甲酯或聚三硅氧烷可显著提高20%氯氟吡氧乙酸EC对空心莲子草地上部分鲜重及再生能力的抑制效果,其中以添加聚三硅氧烷的处理增效最为显著,添加聚三硅氧烷后,20%氯氟吡氧乙酸EC对空心莲子草地上部分鲜重、再生茎叶鲜重的抑制率分别为86.95%和81.66%;添加氮酮、油酸甲酯或聚三硅氧烷后,20%氯氟吡氧乙酸EC药液在空心莲子草叶面的表面张力显著降低,接触角减小,滞留量增加,其中以添加聚三硅氧烷的处理效果最为显著,添加聚三硅氧烷后,20%氯氟吡氧乙酸EC的初始接触角小于50°,180 s时接触角均小于15°,表面张力为25.09 m N/m,滞留量为1.891 g/cm2;添加氮酮或聚三硅氧烷可缩短20%氯氟吡氧乙酸EC药液在空心莲子草叶面正、反面的干燥时间,而添加油酸甲酯则会延长其干燥时间。研究表明,添加助剂改善了20%氯氟吡氧乙酸EC药液在空心莲子草叶面的润湿性能,可能是助剂提高20%氯氟吡氧乙酸EC对空心莲子草防效的原因之一。     

Improved chemical control of Conyza bonariensis in wheat limits problems in the following fallow

Conyza bonariensis is a major weed infesting zero‐tilled cropping systems in subtropical Australia, particularly in wheat and winter fallows. Uncontrolled C. bonariensis survives to become a problem weed in the following crops or fallows. As no herbicide has been registered for C. bonariensis in wheat, the effectiveness of 11 herbicides, currently registered for other broad‐leaved weeds in wheat, was evaluated in two pot and two field experiments. As previous research showed that the age of C. bonariensis, and to a lesser extent, the soil moisture at spraying affected herbicide efficacy, these factors also were investigated. The efficacy of the majority of herbicide treatments was reduced when large rosettes (5–15 cm diameter) were treated, compared with small rosettes (<5 cm diameter). However, for the majority of herbicide treatments, the soil moisture did not affect the herbicide efficacy in the pot experiments. In the field, a delay in herbicide treatment of 2 weeks reduced the herbicide efficacy consistently across herbicide treatments, which was related to weed age but not to soil moisture differences. Across all the experiments, four herbicides controlled C. bonariensis in wheat consistently (83–100%): 2,4‐D; aminopyralid + fluroxypyr; picloram + MCPA + metsulfuron; and picloram + high rates of 2,4‐D. Thus, this problem weed can be effectively and consistently controlled in wheat, particularly when small rosettes are treated, and therefore C. bonariensis will have a less adverse impact on the following fallow or crop.