Chemical Control of Herbicide Monosulfuron Plus Propazine 44% WP against Weeds in Millet Fields and Study on Factors Influencing Yield of Millet

[Objective] The paper was to resolve the poor efficacy or phytotoxicity problems in promotion of herbicide monosulfuron plus propazine 44% WP. [Method] Using orthogonal test and Duncan＇s new multiple range statistical analysis with four factors four levels and three factors two levels, the effects of factors such as herbi- cide dose, irrigation water volume, quality of soil preparation and soil moisture content on chemical control of monosulfuron plus propazine 44% WP against weeds and millet yield were compared in the test. [Result] Seven factors all had great impact on control effect of monosulfuron plus propazine 44% WP against weeds, of which her- bicide dose, irrigation water volume, quality of soil preparation and soil moisture content were the most important factors affecting millet yield. According to millet yield and economic benefit, the optimal scheme to ensure safe, efficient and economic control of monosulfuron plus propazine 44% WP against weeds was as follows： the dose of monosulfuron plus propazine 44% WP was 1 800 g/hm2, the soil was treat- ed after sowing and before seedling emergence; the soil should be smooth and sol- id; the soil moisture should reach 15%; the fields should not be irrigated after herbi- cide application, and the damage of weeds in millet fields could be effectively con- trolled within 45 d during high efficacy duration, especially the damage of dicotyledonous weeds. [Conclusion] The study provided useful information for comprehensive technology of weeds control and ensuring high yield and good harvest of millet.

Theoretical Study on the Structures,Spectra and Thermodynamic Property of Herbicidal Monosulfuron

The structure optimization and frequency calculation have been carried out at the B3LYP/6-31G＊ level towards herbicidal monosulfuron using density functional theory.The computed results showed that the intramolecular hydrogen bond N-H…N can stabilize the molecule.IR spectra,Raman spectra and thermodynamic properties under different temperatures were also obtained.The first vertical excited state electronic transition energy was calculated by time-dependent density function theory,and absorption wavelength of the lowest energy excitation was obtained at 339.59 nm,belonging to the near UV.These results provided the basis for studies on compound＇s structure-activity relationship.

Herbicide activity of monosulfuron and its mode of action

Monosulfuron was developed for weed control in the field of wheat(Triticum, aestivum L.) and millet(Panicum miliaceum L.) with the application rate ranging from 15 to 60 g ai/hm2. Herbicidal activity of monosulfuron was evaluated systematically by bioassay using maize(Zea mays L.) taproot as indicator and weed fresh weight of Acalypha australis L. and Echinochloa phyllopogon. Maize CAU 3138 was the most tolerant cultivars to monosulfuron with IC_ 50(concentration of 50% inhibition) of 85 μg/kg, Yedan 13 was one of the most sensitive cultivars to monosulfuron with IC_ 50 of 6.4 μg/kg. Monosulfuron inhibited the growth of Acalypha australis L. strongly comparing with that of Echinochloa phyllopogon. Monosulfuron was a good acetolactate synthase(ALS) inhibitor in vitro, the I_ 50(50% of inhibition) of monosulfuron, chlorsulfuron, tribenuron-methyl and nicosulfuron for CAU 3138 were 32, 2, 19 and 26 nmol/L respectively, for Yedan 13 the I_ 50 were 15, 3, 17 and 65 nmol/L respectively. In vivo ALS inhibition occurred only in higher concentration of 4 sulfonylurea herbicide tested. Comparison study of this test indicated that the mode of action of monosulfuron was the same as that of other sulfonylurea herbicides such as chlorsulfuron, tribenuron-methyl and nicosulfuron, they were all inhibitors targeted at the ALS.

Residue analysis and dissipation of monosulfuron in soil and wheat

HPLC-UV residue analytical method for monosulfuron [N-[( 4' -methyl) pyrimidin- 2' -yl]-2-nitrophenylsulfonyl urea] in soil and wheat was developed. Monosulfuron residues were recovered by solvent extraction, followed by liquid-liquid partition, and C 18 cartrige clean-up. Excellent method recoveries ranging from 95%—104% for both fortified soil and wheat grain were obtained with coefficients of variation 1.5%—11.8%. The minimum detectable quantities in soil and wheat were both 4 ng, the limit of detection was 0.02 mg/kg. When monosulfuron was applied according to double dosage of maximum recommended use direction(120 g ai/hm 2 of 10% monosulfuron wettable powder sprayed for once during development of wheat) in field studies conducted in Shandong Province and near Beijing, monosulfuron residues was not detected in soil and wheat samples collected 75 d after application. Laboratory soil degradation studies showed that monosulfuron degraded faster in acidic soil and strong alkaline soil than in neutral or weak alkaline soil. Half lives in Jiangxi soil, Shijiazhuang soil, Jiangsu soil and Heilongjiang soil were 41, 48, 87 and 84 d respectively. Monosulfuron residues dissipated rapidly in Shandong and Beijing field test sites with half-lives of less than 14 d.

Synthesis and Crystal Structure of Sodium Monosulfuron (N-(4-Methylpyrimidin-2-yl)-N'-2-(nitrophenylsulfonyl) Urea Sodium)

Monosulfuron is a novel sulfonylurea herbicide with ultra-low dosage invented and patented by Nankai University. Herein its sodium salt was firstly synthesized and crystal structure was determined by X-ray diffraction method. The title compound belongs to the triclinic system, space group P1^- with a = 7.306（6）, b = 9.446（8）, c = 11.872（10）A, α = 76.578（14）, β = 78.049（13）, γ = 77.620（14）°, V = 767.7（11）A^3, Mr = 377.32, Z = 2, Dc = 1.632 g/cm^3,μ= 0.283 mm^-1, F（000） = 388, R = 0.0444 and wR = 0.1186. In the title compound, Na（1） coordinates with 0（4） and 0（5） from one monosulfuron molecule, N（4A） and O（5A） from the other monosulfuron molecule and the oxygen atom from H2O to give five coordination bonds. The title complex is further linked into a three-dimensional structure through π…π interactions and intermolecular hydrogen bonds between the oxygen and nitrogen atoms.

Effects of Light and Monosulfuron on Growth and Photosynthetic Pigments of Anabaena Flos-Aquae Breb

The effects of monosulfuron on growth and photosynthetic pigments of the nitrogen-fixing cyanobacterium Anabaena flos-aquae grown exposed to 2000-, 3000-, and 4000-lux light intensity were studied. Exposed to three light intensities, the seven concentrations of monosulfuron tested can significantly inhibit algal growth in a dose-dependent manner. The cell numbers and growth rate were decreased with the increase in mono-sulfuron concentration, and A. flos-aquae had different degrees of sensitivity to monosulfuron with the most sensitive light intensity being 4000-lux followed by 3000-lux and 2000-lux. The herbicide monosulfuron appeared to have different effects on the synthesis of photosynthetic pigments. The chlorophyll appeared to tackle monosulfuron concentrations. The caroteniod content of algae treated with 0.008 and 0.08 mg/L monosulfuron exposed to 2000-lux had a different stimulatory effect from that of treatments exposed to 3000-lux and 4000-lux, but an inhibitory effect at concentration above 0.8 mg/L. The effect of monosulfuron on biliprotein in cells of A. flos-aquae exposed three light intensities displayed contrary dose dependence.

Synthesis and Crystal Structure of a Sodium Monosulfuron-ester (N-[2'-(4-Methyl)pyrimidinyl]-2-carbomethoxy Benzyl Sulfonylurea Sodium)

Monosulfuron-ester is a novel sulfonylurea herbicide with ultra-low dosage Herein sodium monosulfuron-ester was synthesized and its crystal structure was determined by X-ray diffraction method. The title compound belongs to monoclinic, space group P21/c with a = 9.335（5）, b = 20.632（12）, c = 13.853（8） A, β = 107.193（9）°, Mr = 487.46, Z = 4, Dc = 1.270 g/cm^3, μ = 0.293 mm^-1, F（000） = 1015, R = 0.0859 and wR = 0.2633. In the title compound, Na coordinates with N（1）, O（1） and O（3） from one monosulfuron-ester molecule, N（4A） and O（5A） from the other monosulfuron-ester molecule and one oxygen atom from DMSO to give six coordination bonds.

Adsorption and desorption of herbicide monosulfuron-ester in Chinese soils

Monosulfuron-ester is a new,low rate,sulfonylurea herbicide that is being promoted for annual broadleaf and gramineal weed control;however,there is a lack of published information on its behavior in soils.The adsorption and desorption of monosulfuronester by seven type soils were measured using a batch equilibrium technique.The results showed that the Freundlich equation fitted its adsorption and desorption well,and the Freundlich constant values （K f-ads ） ranged from 0.88 to 5.66.Adsorption isotherms were nonlinear with 1/n f-ads values 1.Soil pH,organic matter （OM）,and clay content were the main factors influencing its adsorption and desorption.Adsorption and desorption were negatively correlated with pH 4.0–8.0 while positively correlated with OM and clay content.The adsorption of monosulfuron-ester was mainly a physical process,because its free energy （？G） in seven soils was less than 40 kJ/mol.Monosulfuron-ester adsorption by three soils increased with increasing CaCl 2 concentration using CaCl 2 as a background electrolyte.Monosulfuron-ester desorption was hysteretic in all tested soils.

10%单嘧磺隆可湿性粉剂防除谷子地杂草田间药效试验

河北和山西的田间药效试验结果表明 ,10 %单嘧磺隆可湿性粉剂 2 2 5、45 0、90 0g/hm2 对谷子地的双子叶杂草有较好的防除效果 ,对单子叶杂草仅有一定的防效 ,试验剂量下对谷子安全 ,有增产作用。田间使用以 10 %单嘧磺隆可湿性粉剂用药 45 0g/hm2 为宜 ,在单子叶杂草较多的地块 。

单嘧磺隆防除小麦田难除杂草碱茅

田间试验证明10%单嘧磺隆可湿性粉剂可有效防除小麦田碱茅的为害,在推荐剂量下防效达到95%以上,优于对照药剂50%丹.乙乳油和45%甲草胺乳油,对小麦安全,而10%苯磺隆可湿性粉剂对碱茅的防效较差,建议与其它药剂混合使用。

单嘧磺隆除草剂分子印迹聚合物的识别特性研究

为了研究印迹聚合物作为固相提取剂在环境分析中的应用,合成了以除草剂单嘧磺隆为印迹分子的印迹聚合物,通过平衡吸附和液相色谱的方法分析了印迹聚合物的识别特性,并研究了不同色谱条件对单嘧磺隆保留因子的影响。研究结果表明,印迹聚合物对印迹分子具有很好的亲和性和特定的选择性,可作为固相提取剂,在单嘧磺隆的残留分析中,对土壤提取样品进行有效的富集与净化。

单嘧磺隆在土壤中的残留分析和消解动态研究

研究了新磺酰脲除草剂单嘧磺隆在土壤中的残留分析方法及其土壤消解动态和最终残留。土壤经甲醇和稀氨水混合液提取 ,液液分配及 C18净化 ,浓缩后用带紫外检测器的高效液相色谱仪进行测定。单嘧磺隆的最低检出量为 4 ng,在土壤中的最低检出浓度为0 .0 2 mg/ kg。本方法的添加回收率为 95.10 %～ 10 3.77% ,变异系数为 1.4 7%～ 11.80 % ,符合农药残留分析的要求。运用上述方法 ,测定了单嘧磺隆在北京和山东土壤中的消解动态以及最终残留。结果表明 :单嘧磺隆在土壤中消解的速度较慢 ,在北京土壤中的半衰期为 9.2 4 d,山东土壤中的半衰期为 13.59d。按推荐剂量施药 ,小麦收获时 ,在北京和山东两地土壤中均未检出单嘧磺隆。

单嘧磺隆对不同小麦品种的耐药性研究

以主根长为指标，研究了５个小麦品系对磺酰脲类除草剂单嘧磺隆的敏感性。 比较了单嘧磺隆对它们的乙酰乳酸合成酶（简称ＡＬＳ）在离体条件下的活性的影响。研 究表明单嘧磺隆对不同小麦品种的耐药能力与其ＡＬＳ的敏感性无关。

单嘧磺隆对小麦的安全性及在麦田除草效果的研究

小麦主根长法测定结果表明 ,小麦品种对单嘧磺隆的相对敏感性有差异 ,以氯磺隆和苯磺隆为对照测定了单嘧磺隆对 9个小麦品种的相对安全性 ,结果表明 ,单嘧磺隆对小麦的安全性与苯磺隆基本相当。温室盆栽试验结果显示 ,茎叶处理和土壤处理 ,0 0 6kg hm2 施药量时油菜产生药害 ;低于 0 0 6kg hm2 施药量时对玉米安全 ;低于 0 12kg hm2 时 ,小麦和谷子的生长均不受影响。田间试验表明 ,10 %单嘧磺隆可湿性粉剂能有效防除麦田杂草如碱茅 [Puccinelliadisants(L .) ]、播娘蒿 [Descurainiasophia (L .)Schur.]、荠菜 [Capsellabursapastoris (L .)Medic .]、早熟禾 (PoaannualL .)等杂草 ,而对小麦安全 ,且茎叶处理优于土壤处理。

单嘧磺隆稳定性的研究

通过高效液相色谱的方法 ,测定了单嘧磺隆在不同有机溶剂中的稳定性 ,研究了温度和光照对单嘧磺隆溶液中单嘧磺隆分解率的影响 .结果表明 ,单嘧磺隆在四氢呋喃和丙酮中较稳定 ,在甲醇中稳定性较差 ,在N ,N 二甲基甲酰胺中极不稳定 ;

单嘧磺隆对靶标乙酰乳酸合成酶活性的影响

本文利用3个对单嘧磺隆敏感性不同的玉米品种为材料,研究了离体和活体条件下单嘧磺隆对乙酰乳酸合成酶(ALS)活性影响的差异,结果发现,单嘧磺隆对不同玉米品种离体ALS的活性影响存在差异,但对同一自交系玉米离体ALS的影响差异不大。活体条件下,低浓度的单嘧磺隆对ALS酶无抑制作用,高浓度则具有抑制作用,这一差异与玉米品种的耐药力无相关性。

创制除草剂单嘧磺隆应用研究

单嘧磺隆是一种高效、低毒除草剂。详细介绍了单嘧磺隆的理化性质、毒理学、环境行为和残留研究。并对单嘧磺隆及其相关产品在小麦、谷子、玉米、水稻等作物田的广泛应用进行了系统的总结。结果表明:单嘧磺隆为低毒农药且对环境安全,无致畸、无致突变、无致癌作用。在推荐剂量下,能有效防除一年生阔叶杂草,而且对作物安全,适宜加工成多种混剂和剂型。

44%谷友WP对谷田杂草的防除及其对谷子产量的影响

为了解决44%谷友WP在推广中的药效不佳或药害问题,采用4因素4水平和3因素2水平的正交试验和新复极差法统计分析,针对施药剂量、喷灌水量、整地质量、土壤墒情等影响因素进行44%谷友(单嘧.扑灭)WP防控杂草及其对谷子产量影响的比较试验。结果表明:7个试验因素对44%谷友WP防控杂草效果均具有重要的影响,其中,施药剂量、灌溉水量、整地质量、土壤墒情是影响谷子产量的最重要因素。根据谷子产量和经济效益,确定了44%谷友WP经济、安全、高效防控谷田杂草技术的最优方案:44%谷友WP的剂量为1800g/hm^2,在播种后出苗前进行土壤处理;耕耙地要坚实;土壤含水量要达到15%;药后不进行喷灌;在45天高药效持续期内能有效控制谷田杂草,尤其是双子叶杂草。

单嘧磺隆除草剂水解机理的理论研究

用量子化学中密度泛函B3LYP方法在6-31G*水平上,对单嘧磺隆的水解机理进行了理论研究.优化了反应过程中反应物、中间体、过渡态及产物的几何构型,并对各个过渡态和中间体进行了振动分析确认其真实性.结果表明:在碱性条件下,水解反应主要经历一个五元环的过渡态TS1,该反应速控步骤的能垒为25.7kJ/mol;在中性条件下,水解反应涉及到一个三元环的过渡态和两个四元环的过渡态,反应的速控步骤为M3'+H2O→TS2',能垒为236.5kJ/mol.从能量上看,碱性条件更有利于水解反应的进行,与实验结果吻合.同时,我们还考虑了溶剂效应对水解反应的影响.

单嘧磺隆对谷子营养价值的影响

采用完全随机设计,通过设置除草剂单嘧磺隆2254、506、75 g/hm23个浓度,研究其对谷子营养价值的影响。结果表明,随着喷药浓度的增加,谷子的粗脂肪含量显著降低,谷子总淀粉、直链淀粉、支链淀粉及氨基酸含量增加,但都低于对照。合理的喷药浓度为450g/hm2,可以改善谷子田间生长环境,相对提高谷子的营养价值。