棉田除草剂氯胺嘧草醚田间使用技术研究

氯胺嘧草醚为2-嘧啶氧基-N-芳基苄胺类新型棉花田除草剂,本文于2014年和2015年在多地通过田间药效试验对该药剂的棉花安全性、杂草防效、杀草谱、持效期及推荐剂量等使用技术进行了研究。结果表明,该药剂在多数试验点对棉花表现安全,而在部分砂壤和碱性土壤条件下使用高剂量防治则有一定药害风险,需降低剂量使用;氯胺嘧草醚杀草谱较广,棉田多数杂草对其敏感;与对照药剂乙草胺和二甲戊灵相比,供试药剂在150g/hm~2剂量下的总草防效略低,而在225或250g/hm~2剂量下的总草防效与对照药剂基本相当;氯胺嘧草醚在药后15d开始发挥药效,持续期在45~60d左右,持效期较长;推荐该药剂在棉田的使用剂量为225~250g/hm~2,而砂壤和碱性土壤条件下需降低用量到75~150g/hm~2。该药剂在棉花播后苗前土壤封闭处理,然后覆膜,兑水量40~50kg/667m~2,可以用于棉田防除一年生禾本科杂草、阔叶杂草和莎草科杂草。     

20%溴嘧草醚悬浮剂的液相色谱分析

本文介绍了以乙腈 水为流动相,采用C18不锈钢柱,245nm波长紫外检测器,对溴嘧草醚进行液相色谱定量分析。该方法的标准偏差为0.1,变异系数为0.49%,线性相关系数为0.9999,平均回收率为99.9%。     

Fenton试剂降解除草剂溴嘧草醚的反应动力学研究

探讨了Fenton试剂对超高效除草剂溴嘧草醚(ZJ0777)的降解反应。考察了溴嘧草醚、过氧化氢、硫酸亚铁的初始浓度和反应温度等因素对溴嘧草醚降解反应的影响,建立了Fenton试剂降解溴嘧草醚的动力学方程。结果表明:在溴嘧草醚初始浓度分别为0.12和0.24 mmol/L时,达到其降解率90%以上所需的时间分别为32和48 h,而在溴嘧草醚为0.48 mmol/L时,反应84 h只有87%的溴嘧草醚降解;过氧化氢初始浓度在150~300 mmol/L范围内,浓度增加有利于降解反应进行;溴嘧草醚降解反应随亚铁离子浓度的增加而加快(5~20 mmol/L),但过高的亚铁离子浓度对降解反应无效。温度在25~45℃范围内,反应的表观活化能Ea为75.34 kJ/mol。溴嘧草醚的氧化降解符合假一级反应动力学模型。     

土壤环境因子对氯胺嘧草醚除草活性的影响

采用常规室内生物测定法,研究了土壤环境因子对氯胺嘧草醚[开发代号ZJ1835,化学名称为N-(2-氯-6-(4,6-二甲氧基嘧啶-2-氧基)苄基)苯胺]除草活性的影响。结果表明:土壤质地、p H值、有机质含量、土壤湿度和温度对其除草活性均能产生一定影响。氯胺嘧草醚在砂土和黏土中的活性高于壤土,其除草活性随土壤有机质含量、p H值和土壤湿度的升高而升高,而温度偏高或偏低均不利于其药效发挥,在15~25℃环境条件下除草活性最佳。     

氯胺嘧草醚在土壤中的吸附行为研究

为评价氯胺嘧草醚的环境安全性,采用批量平衡法测定了氯胺嘧草醚在5种土壤中的吸附-解吸行为,并运用数学模型对其吸附-解吸特性及移动性能进行了分析。结果表明:氯胺嘧草醚在5种土壤中的等温吸附-解吸曲线符合Freundlich模型,吸附常数（Kf值）范围在6.991~18.49之间;不同土壤对其的吸附作用强弱依次为:黑土 > 水稻土 > 褐土 > 潮土 > 红土。氯胺嘧草醚在5种土壤中的有机碳吸附常数（KOC）范围在704.4~1 579之间,推测其在土壤中具有低移动性;薄层层析试验也表明,氯胺嘧草醚在土壤中的移动性较弱。氯胺嘧草醚在5种土壤中的吸附自由能绝对值均小于40 kJ/mol,表明其吸附机理主要是物理吸附。其Kf值与土壤有机质含量、黏粒含量呈正相关,而与土壤pH值呈负相关。解吸试验表明,氯胺醚在其中3种土壤中的解吸过程存在滞后现象。研究表明,在正常使用情况下,氯胺嘧草醚不易对地表水或地下水造成污染风险。     

溴嘧草醚与胺苯磺隆混配制剂对油菜田杂草的室内防除效果筛选研究

溴嘧草醚(代号:ZJ0777)为化学结构新颖的油菜田专用除草剂,为扩大其杀草谱,提高除草活性,我们以日本看麦娘(Alopecurus aequalis)和小藜(Chenopodiumalbum)等为试验靶标进行了与胺苯磺隆(Ethametsulfuron)混用的室内防除效果配方筛选研究,并采用共毒系数法和等效线法对二者混用的联合作用进行评价。结果表明,两者混用后表现相加或增效作用,最佳配比为溴嘧草醚∶胺苯磺隆质量比为1:0.2。     

乙氧氟草醚防除地膜棉田杂草试验初报

随着地膜棉栽培技术的广泛应用 ,棉田杂草的发生期相应提前 ,加之长期使用氟乐灵进行土壤封闭处理 ,棉田草相发生变化 ,禾本科杂草种类和数量下降 ,阔叶草密度增加 ,上升为优势杂草 ,严重影响地膜棉花正常生长。为寻求适宜的除草剂品种与配方 ,2 0 0 0年我们进行了乙氧氟草醚土壤封闭防除地膜棉田杂草试验 ,取得了较好的效果 ,现将试验结果报告如下 :1　材料与方法1 1　供试药剂( 1 ) 50 %乙草胺ＥＣ(大丰农药厂产 ) ;( 2 )2 0 %乙氧氟草醚ＥＣ (响水农药厂产 ) ;( 3)48%氟乐灵ＥＣ(以色列科尔公司产 ,国内加工 )。1 2　防除对象试验棉田…     

呋喃磺草酮原药中主要杂质的结构鉴定及其合成

针对HPPD除草剂呋喃磺草酮原药生产中产生的3个质量分数均大于0.1%的主要杂质,通过高效液相色谱、核磁共振氢谱和高分辨质谱对3个杂质的结构进行了结构鉴定,发现其中2个为未见文献报道的化合物。结合生产工艺对杂质产生的路径进行了分析,并成功进行了合成。该研究对呋喃草酮原药质量控制和安全产生具有重要意义。     

嘧草醚在水稻及其环境中的残留

采用改良的QuEChERS-高效液相色谱-质谱 (HPLC-MS) 技术,建立了嘧草醚在水稻及其环境中残留量的检测方法。样品经V (乙腈) : V (甲酸) = 199 : 1的混合溶液提取,由十八烷基键合硅胶 (C₁₈) 或C₁₈ + 丙基乙二胺 (PSA) 吸附剂净化。以V (乙腈) : V (0.1%甲酸水溶液) = 70 : 30的混合溶液为流动相,经ZORBAX Eclipse XDB-C₁₈色谱柱分离,采用电喷雾正离子 (ESI+) 模式扫描,HPLC-MS检测,外标法定量。结果表明:在0.01~1 mg/L范围内嘧草醚的峰面积与其质量浓度间线性关系良好,在乙腈、稻田水、土壤、稻株、糙米和稻壳中的相关系数均大于0.99。嘧草醚在稻田水中的检出限 (LOD) 为0.0015 mg/L,定量限 (LOQ) 为0.005 mg/L,在土壤、糙米、稻壳和稻株中的LOD分别为0.003、0.015、0.015 和0.003 mg/kg,LOQ分别为0.01、0.05、0.05 和0.01 mg/kg。在0.005、0.01和0.1 mg/L (或mg/kg) 添加水平下,嘧草醚在稻田水、土壤和糙米中的平均回收率分别为95~109%、92%~106%和89%~107%,相对标准偏差 (RSD) 分别为3.0%~5.0%、1.1%~2.9%和3.1%~3.7%;在稻壳和稻株中的平均回收率分别为95%~102%和93%~107%,RSD分别为1.1%~3.8%和3.5%~9.9%。该方法灵敏度、精密度和准确度均符合农药残留分析要求。     

溴嘧草醚悬浮剂防除油菜田杂草的研究

20%溴嘧草醚悬浮剂是具有自主知识产权的油菜田新型除草剂.2003～2005年在不同区域油菜田的试验结果表明,溴密草醚SC 45～90 g a.i./hm2对禾本科杂草看麦娘、日本看麦娘、茼草和阔叶杂草蓼、臭荠、雀舌草等防效达80%以上,对牛繁缕、繁缕、碎米荠和稻茬菜也有中等到良好的防效,对总草防效达72.0%～94.4%.对油菜安全,除草后油菜明显增产.     

Spatial and temporal changes in acetolactate synthase activity as affected by new herbicide ZJ0273 in rapeseed, barley and water chickweed

Propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), derived from a precursor compound pesticide (a derivative of 2-pyrimidinyloxy-N-aryl benzoate), is a novel herbicide used in the rapeseed field. This paper studied the differential tolerance or susceptibility of four plant species viz. Brassica napus L. (rapeseed), Hordeum vulgare L. (barley), Malachium aquaticum (L.) Fries (water chickweed), and Alopecurus aequalis Sobol. (equal alopecurus), to various concentrations of ZJ0273, based on the rate of inhibition of acetolactate synthase (ALS) activity. Brassica napus was observed as the most tolerant among four species in which ALS activity in vivo was hardly affected by ZJ0273 at 100 mg/L (recommended dose in the rapeseed field). In contrast, H. vulgare was found to be more susceptible which was reflected in the relative decline of ALS activity and lower biomass production even under at a lower rate of 10 mg/L of ZJ0273. The two weed species exhibited moderate susceptibility as compared to H. vulgare. The present study confirmed that ZJ0273 at 100 mg/L is the optimal dose of herbicide for rapeseed field. Seedling stage was critical in determining the tolerance of crops and susceptibility of weeds which indicated that over seven leaf stage was much safer for rapeseed whereas the two leaf stage juvenile water chickweed was more susceptible to the same rate of ZJ0273. Spatial and temporal variations in ALS activity as affected by 100 mg/L ZJ0273 in water chickweed, rapeseed and barley also suggested that the synchronized sampling based on the tissue position and seedling stage was necessary to examine precisely, the special difference in tolerance or susceptibility to ALS-inhibiting herbicide. The uppermost younger leaf seemed to be the most appropriate sample for evaluation. Furthermore, the variant tendency of ALS activity from different parts of plants between monocotyledons and dicotyledons to ZJ0273 treatments showed differential response which revealed some possible mechanism related to the altered absorption and translocation of the herbicide.     

Dimethoxypyrimidines as Novel Herbicides. Part 2. Synthesis and Herbicidal Activity of O-Pyrimidinylsalicylates and Analogues

A new series of the O-pyrimidinylsalicylates was synthesized and their herbicidal activity was examined. Some of these compounds showed very strong herbicidal activity under pre- and post-emergent treatment conditions against various kinds of grass and broadleaf weeds. Among these compounds, O-(4, 6-dimethoxypyrimidin-2-yl) salicylic acid and its methyl ester were found to exhibit the highest activity. The herbicidal symptoms observed after the treatments included early cessation of plant growth followed by chlorosis, necrosis and plant death. The symptoms were similar to those caused by sulfonylureas and imidazolinones, which inhibit branched-chain amino acid biosynthesis.     

新型N-芳基-2-((5-((4,6-二甲基嘧啶-2-基)硫甲基)-1,3,4-噻二唑-2-基)硫)乙酰胺类化合物的合成及杀菌活性

为寻找新型杂环活性化合物,通过活性亚结构拼接,以硫脲和乙酰丙酮为起始原料合成4,6-二甲基嘧啶-2-硫醇,随后经酯化、肼化、环化和缩合反应,设计并采用微波辅助合成了10个新型N-芳基-2-（（5-（（4,6-二甲基嘧啶-2-基）硫甲基）-1,3,4-噻二唑-2-基）硫）乙酰胺类化合物,其结构通过核磁共振氢谱和碳谱、红外光谱、质谱及元素分析确认。初步生物活性测试结果表明,在50 mg/L下,大部分目标化合物对植物病原真菌具有一定的抑制活性,其中化合物8h对黄瓜炭疽病菌Colletotrichum orbiculare的抑制率达77.3%。     

2-[4-(对氟苯基)噻唑-2-基]-3-羟基-3-烃氧基丙烯腈的合成及杀菌活性

为了寻找生物活性良好的噻唑基丙烯腈类化合物,利用2-氰甲基-4-(对氟苯基)噻唑( 3 )与取代氯甲酸酯( 4 )在碱存在下反应,合成了15个未见文献报道的2- -3-羟基-3-烃氧基丙烯腈化合物( 5 ),其结构经核磁共振氢谱、质谱和元素分析表征。初步杀菌活性测试结果表明:所有化合物在试验浓度下均具有一定的抑菌活性,尤其对炭疽病菌Colletotrichum gossypii表现出较好的抑制活性,在质量浓度25 mg/L下,所有化合物的抑制率均在50%以上,其中化合物 5a、5e、5g、5k、5n和5o 的抑制率在80%以上。     

N-(芳基磺酰氨基乙基)-1,6-己内酰胺的合成及杀菌活性

以环己酮为原料,合成了9个结构新颖的N-(芳基磺酰氨基乙基)-1,6-己内酰胺( 3 ),其结构均经IR、1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,部分化合物对供试的6种病原真菌具有一定的杀菌活性,其中 3a、3b、3d和3g 对番茄叶霉病菌的抑制活性与对照药剂百菌清相当,抑制率大于90％。     

Differential morphological and physiological responses of two oilseed Brassica species to a new herbicide ZJ0273 used in rapeseed fields

Weeds are considered as a major threat to the production of oilseed Brassica crops. The use of herbicides that are safe for crops and effective in controlling weeds is crucial for the agronomists and farmers. Propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), a derivative of 2-pyrimidinyloxy-N-aryl benzoate, is a new herbicide used in the rapeseed field. To evaluate the tolerance of Brassica species against this new herbicide, two cultivars of rapeseed Brassica napus cv. ZS 758 and Brassica rapa cv. Xiaoyoucai were tested by a foliar spray of ZJ0273 at the rate of 100, 500 and 1000 mg/L and a currently used ALS (acetolactate synthase)-inhibiting herbicide bispyribac-sodium (BS) at the rate of 100 mg/L. The results showed that both the cultivars of Brassica were less affected by ZJ0273 as compared to BS. Increasing level of ZJ0273 herbicide from 100 to 1000 mg/L increased the stress for the plants of both the cultivars as indicated by enhanced accumulation of malondialdehyde content. The activities of ALS and antioxidant enzymes (superoxide dismutase and peroxidase), soluble protein and sugar contents, photosynthetic system (SPAD value, photosynthetic rate and chlorophyll fluorescence) as well as the agronomic characters also declined consistently with each successive increase in ZJ0273 concentration. In general, the plants treated with 100 mg/L ZJ0273 recovered from the herbicide stress after 28 days. B. napus showed more tolerance than B. rapa to the new herbicide. Nevertheless, BS application at 100 mg/L did not allow the plants of both the cultivars to recover from the herbicidal stress.