异唑草酮及其混剂噻酮·异唑的除草活性及对玉米的安全性

异噁唑草酮和噻酮·异噁唑是新型?广谱?高活性的土壤处理除草剂?明确异噁唑草酮和噻酮·异噁唑对玉米田杂草的除草活性及对玉米的安全性是该药剂在玉米田应用的重要内容?本文采用温室整株生物测定法研究了两种药剂对玉米田常见杂草的除草活性及对玉米的安全性?结果表明:20%异噁唑草酮悬浮剂和26%噻酮·异噁唑悬浮剂土壤处理对玉米田杂草有较高的除草活性, 两种药剂对各种杂草的GR90均低于田间推荐剂量?20%异噁唑草酮悬浮剂土壤处理对阔叶杂草藜?苘麻?反枝苋和苍耳均有较高的除草活性, GR90均小于54 g/hm 2, 对禾本科杂草狗尾草?马唐?稗和野黍也有较高的除草活性, GR90均小于63 g/hm 2?26%噻酮·异噁唑悬浮剂对阔叶杂草藜?反枝苋?苘麻和苍耳也有较高的除草活性, GR90均小于62 g/hm 2, 对禾本科杂草狗尾草?马唐?稗和野黍也有较高的除草活性, GR90均小于59 g/hm 2?20%异噁唑草酮悬浮剂和26%噻酮·异噁唑悬浮剂土壤处理对玉米的安全性很高, 对玉米和杂草的选择性指数均高于17?异噁唑草酮及其混剂噻酮·异噁唑用药量低?除草活性强?对玉米安全, 是玉米田土壤处理除草剂较为理想的替代产品?     

75%异噁唑草酮水分散粒剂高效液相色谱分析方法

本文采用高效液相色谱法,以乙腈+冰乙酸(pH=3)溶液为流动相,使用C_(18)色谱柱和二极管阵列检测器,在220nm波长下对试样中的异噁唑草酮进行分离和定量分析。结果表明异噁唑草酮的线性相关系数分别为0.999;标准偏差为0.02;变异系数为0.02%;平均回收率99.75%。     

除草剂对小麦田雀麦的生物活性测定

为筛选防除雀麦Bromus japonicus的高效除草剂,采用室内生物测定法研究了13种除草剂对雀麦的除草活性及5种除草剂的田间药效试验。结果表明,在田间推荐剂量的低剂量下,氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆、磺酰磺隆、丙苯磺隆7种除草剂对雀麦具有很高的防除效果,21 d鲜重抑制率分别为88.30%、86.32%、83.97%、78.47%、76.76%、72.83%、71.39%,高剂量下的21 d鲜重抑制率达98.57%、95.36%、91.58%、91.46%、89.47%、82.48%、82.20%;其中氟唑磺隆各剂量下的防效较其它除草剂高。而嘧啶肟草醚、苯唑草酮、炔草酯、吡氟酰草胺、唑啉草酯、精噁唑禾草灵6种除草剂对雀麦防效较差。氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆5种除草剂的田间药效试验表明,氟唑磺隆对雀麦防效最高,高剂量下20 d株防效达85.04%,药后40 d株防效和鲜重防效分别达83.94%和84.17%,未见小麦有明显药害症状,建议田间推荐用量为21.00~42.00 g(a.i.)/hm~2。表明雀麦对不同除草剂的敏感性存在差异,在供试的13种除草剂中氟唑磺隆对雀麦防效最高,较为安全,为防除雀麦的理想除草剂。     

异噁唑草酮对玉米根际土壤微生物量碳、氮和酶活性的影响

为明确异噁唑草酮对玉米根际土壤微生物碳、氮及酶活性的影响, 采用田间试验的方法, 以1倍、5倍和10倍田间推荐剂量为供试除草剂剂量, 测定了异噁唑草酮土壤封闭处理对玉米根际土壤微生物量碳、氮及土壤脲酶、过氧化氢酶、蔗糖酶、脱氢酶和中性磷酸酶活性的影响。结果表明:推荐剂量的异噁唑草酮对玉米根际土壤微生物量碳、氮含量无显著影响, 5倍和10倍推荐剂量的异噁唑草酮对玉米根际土壤微生物量碳、氮含量具有抑制作用。推荐剂量的异噁唑草酮对玉米根际土壤脲酶、过氧化氢酶和蔗糖酶影响较小, 5倍和10倍推荐剂量的异噁唑草酮对其具有明显的抑制作用。异噁唑草酮对土壤脱氢酶活性具有抑制作用, 且施用剂量越高, 抑制作用越强。异噁唑草酮对土壤中性磷酸酶活性的影响表现为前期促进, 后期抑制, 且施用剂量越大, 促进或抑制作用越强。研究表明:推荐剂量的异噁唑草酮对玉米根际土壤微生物量碳、氮及土壤脲酶、过氧化氢酶和蔗糖酶活性的影响较小, 但对土壤脱氢酶、中性磷酸酶活性有影响。     

噻酮·异噁唑对玉米根际土壤微生物量碳、氮和酶活性的影响

为明确噻酮·异噁唑对玉米根际土壤微生物量碳、氮及酶活性的影响,采用田间试验的方法,测定了田间推荐剂量、5倍推荐剂量和10倍推荐剂量的噻酮·异噁唑土壤封闭处理对玉米根际土壤微生物量碳、氮及土壤脲酶、过氧化氢酶、蔗糖酶、中性磷酸酶和脱氢酶活性的影响。结果表明,推荐剂量的噻酮·异噁唑处理后,玉米根际微生物量碳、氮与对照无显著差异,处理后28 d, 5倍推荐剂量和10倍推荐剂量处理的玉米根际土壤微生物量碳、氮受到抑制,与对照有显著差异。推荐剂量的噻酮·异噁唑对玉米根际土壤酶活性影响小,与对照无显著差异,5倍和10倍推荐剂量的噻酮·异噁唑对土壤脲酶、过氧化氢酶、蔗糖酶和脱氢酶活性具有抑制作用,但试验后期可恢复到对照水平,5倍和10倍推荐剂量的噻酮·异噁唑对中性磷酸酶活性有显著的抑制作用,施药后不可恢复到对照水平。研究表明:推荐剂量的噻酮·异噁唑对玉米根际土壤微生物量碳、氮及土壤酶活性的影响小,试验后期可恢复到对照水平。     

麦田布顿大麦草的化学防除药剂筛选

布顿大麦草为麦田入侵杂草, 为尽早建立对该杂草的化学防除技术, 本研究采用室内盆栽法测定了布顿大麦草对21种除草剂的敏感性?结果表明:土壤处理剂41%氟噻草胺悬浮剂对布顿大麦草具有良好的防除效果, 42%氟啶草酮悬浮剂?60%丁草胺乳油?40%砜吡草唑悬浮剂?960 g/L精异丙甲草胺乳油对布顿大麦草的防除效果一般, 50%扑草净可湿性粉剂?50%异丙隆可湿性粉剂?45%二甲戊灵微囊悬浮剂?50%吡氟酰草胺可湿性粉剂防除效果不理想; 茎叶处理剂7.5%啶磺草胺水分散粒剂?12.5%烯禾啶乳油?41%草甘膦异丙胺盐水剂对布顿大麦草防除效果好, 5%咪唑乙烟酸水剂?8%炔草酯水乳剂?30 g/L甲基二磺隆可分散油悬浮剂?8%烟嘧磺隆可分散油悬浮剂?7%双唑草腈颗粒剂?70%氟唑磺隆水分散粒剂对布顿大麦草的防除效果一般, 5%唑啉草酯乳油?7.5%双环磺草酮颗粒剂?69 g/L精噁唑禾草灵水乳剂防除效果不理想?氟噻草胺?在推荐剂量492 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率为75.40%; 啶磺草胺?草甘膦异丙胺盐?烯禾啶在推荐剂量14?1 500?187.5 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率分别为73.96%?60.60%?65.07%?综合本研究结果及除草剂使用特性, 麦田布顿大麦草可采用氟噻草胺土壤封闭或者啶磺草胺茎叶喷雾处理进行有效防除; 油菜田布顿大麦草可采用烯禾啶进行防除; 非耕地布顿大麦草可采用草甘膦异丙胺盐进行防除?     

异噁唑草酮及其代谢物在玉米中残留分析方法

建立了采用分散固相萃取为样品前处理方法的高效液相色谱-串联质谱(HPLCMS/MS)快速检测玉米中异噁唑草酮及其代谢物DKN的残留的分析方法。样品经乙腈提取,C18吸附剂净化,电喷雾电离、负离子模式采集,多反应监测模式检测,基质匹配标准品外标法定量。结果表明:在0. 005～0. 5mg/L范围内,异噁唑草酮及DKN在玉米等中的质量浓度与对应的峰面积间呈良好的线性关系,其相关系数均0. 992 2。在0. 01～0. 1 mg/kg添加水平下,异噁唑草酮及DKN在玉米、青玉米和秸秆平均回收率为95%～108%,相对标准偏差(RSD)为2%～11%。异噁唑草酮及DKN在玉米等基质中的定量限(LOQ)均为0. 01mg/kg。该方法简便、快速、准确,可用于玉米中异噁唑草酮及DKN的残留检测。     

有效防除麦田抗性杂草荠菜的新型除草剂——双唑草酮

双唑草酮为中国创制的新型对羟基苯基丙酮酸双氧化酶(HPPD)抑制剂类除草剂,已于2018年取得中国农药登记。为了测定其对麦田抗性杂草荠菜的除草效果,共采集了36个荠菜种群,其中1个敏感种群采自未施用过除草剂的路边,其他35个疑似抗性种群均采自于中国苯磺隆使用历史超过20年的冬小麦田。在温室中采用整株盆栽法测定了荠菜种群对双唑草酮、苯磺隆、双氟磺草胺、甲基二磺隆、唑草酮和2甲4氯的抗性水平。结果表明,有28个种群对苯磺隆产生了抗性,其中种群K16009、K17005、15053和17003表现出高水平抗性。这4个种群对其他除草剂的交互抗性检测试验表明:种群K16009、K17005和15053对双氟磺草胺和甲基二磺隆表现出高水平交互抗性,其抗性指数范围为25-321,其GR₅₀值远高于供试药剂登记的田间推荐剂量;而上述4个抗性种群对双唑草酮、唑草酮和2甲4氯均较为敏感,其GR₅₀值均低于供试药剂登记的田间推荐剂量。唑草酮和2甲4氯也可用于小麦田抗性荠菜种群的防治,但该类药剂对施药时间要求较为严格。本研究结果表明,双唑草酮可有效防除对乙酰羟基酸合成酶（AHAS）类除草剂已经产生抗性的荠菜。     

异噁草酮对土壤微生物和土壤酶活性的影响

本试验检测了异噁草酮处理土壤后土壤中微生物群落数量和土壤酶活性变化,目的在于研究异噁草酮对土壤微生态产生的影响。结果表明:土壤中异噁草酮有效成分浓度为200、500μg/kg和700μg/kg时,促进土壤中细菌和真菌数量增长,该数量在处理7d之内就会明显变化,并且此影响随异噁草酮使用浓度的提高而增强,但异噁草酮对放线菌的数量无显著影响。施用异噁草酮后,土壤酶活性反应程度由高到低的顺序为:转化酶多酚氧化酶过氧化氢酶。本研究中异噁草酮施入土壤后,除对多酚氧化酶有明显抑制作用,且该抑制作用在短时间内可恢复外,对土壤微生物数量和土壤酶活性都有促进作用。     

氟噻草胺与氟唑磺隆混配协同作用及在小麦田杂草防治中的应用

本文通过室内生物测定研究了氟噻草胺与氟唑磺隆对小麦及多花黑麦草的活性,田间试验测定了二者混配对阔叶杂草的防效及对小麦分蘖数的影响。室内水培法测定结果表明,氟噻草胺、氟唑磺隆对多花黑麦草有效抑制中剂量(ED50)分别为0.37mg/L和105.91mg/L,氟噻草胺与氟唑磺隆混配比例为8∶2、12∶2、16∶2、20∶2时,共毒系数(CTC)分别为94.3、239.7、198.1、156.5,表明氟噻草胺与氟唑磺隆混用具有相加或增效作用,其中以12∶2、16∶2比例混配对多花黑麦草防治增效最为显著。盆栽试验结果表明,苗前以12∶2和16∶2比例土壤封闭喷施对小麦与多花黑麦草的选择性指数为1.51和1.43;苗后3d及苗后15d茎叶喷施对多花黑麦草与小麦选择性较差,选择性指数低于1。田间测定结果表明,氟噻草胺与氟唑磺隆混配对阔叶杂草荠菜、播娘蒿、婆婆纳防效优于氟噻草胺单独使用,混配条件下株防效为85.45%~100%,鲜重防效为89.57%~100%,对小麦分蘖数无显著影响。     

Sorption of isoxaflutole by five different soils varying in physical and chemical properties

Isoxaflutole is a new pre-emergence corn herbicide which controls both grass and broadleaf weeds. Experiments were performed in the laboratory to study the sorption of isoxaflutole in five different soils (Moorhead, MN; East Monroe, CO; Ellendale, MN; South Deerfield, MA; and Chelsea, MI) using the batch equilibration technique. Total initial isoxaflutole solution concentrations for each soil were 0.05, 0.15, 0.3. 0.8, 1.5, 2.0 and 4.0 mg litre⁻¹. Analysis of [ring-¹⁴C] isoxaflutole was performed using liquid scintillation counting, and sorption data were fitted with the Freundlich model. Isotherms of isoxaflutole in all the soils were non-linear as depicted by the exponent (n < 1.0), indicating differential distribution of sorption site energies in various soils. Since the isotherms were non-linear the data fit Freundlich's isotherm well, as was indicated by high values of the regression coefficient (r²). The Freundlich sorption coefficient ranged from 0.555 to 50.0 (litre ⁿmg ^l−nkg⁻¹). Multiple regression of the sorption constant, K_F against selected soil properties indicated that organic matter content was the best single predictor of isoxaflutole sorption (r² = 0.999) followed by soil pH (r² = 0.954). Clay content of the soils did not have a high correlation with K_F values (r² = 0.453), while the sorption of isoxaflutole was not influenced by the Ca²⁺ concentration in the soil solution. Isoxaflutole sorption increased with an increase in organic matter content of soils. Sorption of isoxaflutole decreased as the soil pH increased from 4.5 to 8.5, which was depicted by the reduction of K_F values. Sorption of isoxaflutole to the soils varied with differences in binding energies. At a particular net energy value (E*), the corresponding site energy distribution [F(E*)] values followed the order, Chelsea, MI > Moorhead, MN > East Monroe, CO > South Deerfield, MA > Ellendale, MN. The negative magnitude of Gibbs free energy of sorption (ΔG ^x) indicates the spontaneity of the given sorption process in the soils from Moorhead, MN; East Monroe, CO and Chelsea, MI. © 1999 Society of Chemical Industry     

Influence of nitrogen fertilization and isoxaflutole on the nodulation of chickpea (Cicer arietinum)

The effects of soil nitrate and the herbicide, isoxaflutole, on chickpea nodulation were examined in a glasshouse experiment. The treatments consisted of one isoxaflutole‐tolerant and one isoxaflutole‐sensitive chickpea cultivar, five nitrate concentrations (0, 0.75, 1.5, 3.0, and 6.0 mmol L^?1), and three herbicide rates (0, 75 [the recommended rate], and 300 g ha^?1). The sensitive cultivar was more susceptible to isoxaflutole damage with an increasing herbicide rate and nitrate concentration, compared with the tolerant cultivar. Isoxaflutole at the recommended rate reduced the nodule dry weight of the sensitive cultivar by 51% and by 33% in the tolerant cultivar. The nodule dry weight of the sensitive cultivar was reduced by 28%, 40%, 64%, and 76% with the addition of the 0.75, 1.5, 3.0, and 6.0 mmol L^?1 nitrate concentrations, respectively. In comparison, the nodule dry weight of the tolerant cultivar was reduced by 50% and 79% at the 3.0 and 6.0 mmol L^?1 nitrate concentrations, respectively. In addition, the level of damage from increasing rates of isoxaflutole increased with the highest nitrate concentrations of 3.0 and 6.0 mmol L^?1, regardless of the cultivar. Isoxaflutole at the recommended application rate had a detrimental effect on the nodulation of both chickpea cultivars, but the isoxaflutole‐tolerant cultivar suffered less injury than the sensitive one in relation to some growth parameters. The damage to chickpea from the recommended rate of isoxaflutole also increased with soils of higher nitrate content.     

Sorption–desorption of 'aged' isoxaflutole and diketonitrile degradate in soil

Isoxaflutole is a relatively new herbicide used for weed control in maize. The objective of this research was to increase the understanding of the behaviour and environmental fate of isoxaflutole and its diketonitrile (DKN) degradate in soil, including determination of the strength of sorption to soil and whether sorption is affected by ageing. In sandy loam (SL) and silty clay (SiCl) soils, ¹⁴C‐isoxaflutole was found to dissipate rapidly after application to soil; recovery ranged from ～42% to 68% at week 0, and recovery had decreased to <10% at week 12. Decreases in ¹⁴C isoxaflutole residues over time in SL and SiCl soils are consistent with hydrolysis of isoxaflutole and formation of bound DKN residues in the soil. DKN recovery from freshly treated SiCl and SL soils was 41% to 52%. After a 12‐week incubation in SL soil at pH 7.1 and 8.0, recoveries were similar, ～40%. However, at week 12 in SL soil pH 5.7, DKN recovery decreased to ～28%. DKN recovery in SiCl soil at week 12 was <10%. Increases in sorption of DKN in SL at pH 5.7 and SiCl soil over time indicate that the DKN degradate is tightly bound to the soil and sorption is affected by soil pH and soil type. Sorption of ¹⁴C‐DKN in the SiCl soil more than doubled with ageing compared with the lower K_d sorption coefficient values of the SL soils. In the SiCl soil at time 0, the K_d was 0.6; at 1 week, K_d increased to 2; and at the end of the 12‐week incubation period, K_d was 4.5. This strong binding of DKN to the soil may be due to chelate formation in the interlayer of the clay.     

异噁唑草酮在土壤表面光解及在土壤中的降解和淋溶特性

为合理评估除草剂异唑草酮的环境风险,在实验室模拟条件下,研究了异唑草酮在土壤 (红壤土)表面光解以及在不同质地土壤 (潮土、水稻土和红壤土) 中的降解和淋溶特性。结果表明:异唑草酮在土壤表面的光解遵循一级反应动力学方程c_t = 4.23e–0.008t (r = 0.937),半衰期为82.5 h;其在潮土、水稻土和红壤土中的降解均符合一级动力学方程,好氧条件下,异唑草酮在3种土壤中的降解半衰期分别为10.5、43.3和139 h,厌氧条件下的降解半衰期分别为19.4、18.4和158 h;其在潮土、水稻土和红壤土中的淋溶系数 (R_f) 分别为0.417 0、0.083 3和0.083 3。研究表明:异唑草酮在土壤表面光解速率较慢,而在土壤中好氧及厌氧条件下降解速率均较快,残留期短;其在土壤中淋溶性较弱,不易对周围环境及地下水造成污染风险。     

25％福美双·克百威·萎锈灵悬浮种衣剂液相色谱分析

本文采用高效液相色谱法,以C18为固定相,甲醇+水为流动相,用紫外检测器定量测定混剂中福美双、克百威和萎锈灵的含量。本方法的变异系数分别为0.11%、0.01%、0.03%;标准偏差分别为0.013、0.007、0.021;平均回收率分别为99.35%、99.17%、99.60%;线性相关系数分别为0.9996、0.9989、0.9994。     

胺苯磺隆·草除灵·噁唑禾草灵悬浮剂液相色谱分析

本文采用高效液相色谱法，以C18柱为固定相，甲醇 水为流动相，用236nm紫外检测器定量测定胺苯磺隆、草除灵、恶唑禾草灵混剂的含量。本方法的变异系数分别为0．65％、0．06％、0．40％；标准偏差分别为0．013、0．009、0．0323平均回收率分别为98．31％、100．05％、99.13％；线性相关系数分别为0．9956、0．9978、0.9988。     

2种增效剂对春玉米田除草剂的减量增效作用

为了明确2种增效剂对除草剂的减量效应,为除草剂科学减施及增效剂安全使用提供数据基础,2019年在西北荒漠绿洲生态区春玉米田,以38.5％硝·精·莠去津CS和26.7％噻隆·异噁酮SC作为茎叶处理剂,测定了激健和辉丰2种增效剂在不同施药剂量下的除草效果.结果 表明:在38.5％硝·精·莠去津CS 2310 mL/hm和2...     

12％氟唑菌酰胺·氟环唑乳油高效液相色谱分析

本文采用高效液相色谱法,以乙腈加0.1%磷酸水溶液为流动相,使用Eclipse Plus C 18色谱柱和二极管阵列检测器,在210nm波长下对12%氟唑菌酰胺·氟环唑乳油进行分离和定量测定。结果表明,该分析方法条件下氟唑菌酰胺和氟环唑的线性相关系数分别为0.9997和0.9991,标准偏差分别为0.02和0.02,变异系数分别为0.31%和0.32%,平均回收率分别为100.18%和100.44%。