农田尾菜发酵过程中农药残留变化特征

基于尾菜中存在农药残留的现状,以设施农业尾菜黄瓜秧为研究对象,采用气相色谱法和超高效液相色谱-串联质谱法检测了尾菜黄瓜秧在静态好氧发酵过程中多菌灵、吡虫啉、哒螨灵等50种农药残留的动态变化,并分析发酵重要影响因子堆高对农药残留消解的影响。结果表明:在尾菜黄瓜秧中共检测出腐霉利、多菌灵、嘧菌酯、苯醚甲环唑、烯酰吗啉、虫螨腈、吡虫啉、啶虫脒和哒螨灵9种农药残留,其中多菌灵平均残留量最高,达11.2 mg/kg,其他8种农药平均残留量在0.042~0.89 mg/kg之间。在发酵的24 d中,不同堆高条件下9种农药的消解规律均符合一级反应动力学方程,但不同农药半衰期差异较大,其中吡虫啉的平均半衰期最长,为28.9 d,多菌灵的平均半衰期最短,为10.2 d;不同堆高处理中农药的消解速率也有差异,总体上在2.5 m堆高下各农药的消解率最高、半衰期最短。本研究结果可为尾菜发酵参数优化、农业废弃物的高效资源化利用以及研发基于尾菜发酵产物的有机蔬菜专用有机肥提供理论支撑。     

Herbicide Performance in Rainfed Cabbage

Abstract

The effectiveness of butralin (2.0 and 4.0 kg a.i./ha pre-plant, 2.0 and 4.0 kg a.i./ha pre-em), chlorthal-dimethyl (10.0 and 12.0 kg a.i./ha pre-em), trifluralin (0.6 and 1.1 kg a.i./ha pre-plant) chloramben (2.0 kg a.i./ha pre-em) and nitrofen (2.0 kg a.i./ha pre-em) in controlling weeds in transplanted ‘Kono Cross’ cabbage and the influence of these treatments on the yield and quality of marketable heads and on the economics of weed control were evaluated in three replicated field experiments on River Estate loam soil in Trinidad during the wet seasons of 1976 and 1977. While herbicides did not affect the size of the cabbage plant population or the date to maturity of the crops, they reduced the cost of weed control by over 30% and increased the net returns relative to the clean-weeded control by over 9%. Butralin at 4.0 kg a.i./ha pre-plant and pre-em and the trifluralin treatments were superior to nitrofen which gave good weed control up to five weeks and higher yields than the clean-weeded control. Chlorthal-dimethyl gave encouraging results but caused slight, temporary stunting. The application of one of these treatments followed by one hand weeding at about four weeks should give full-season weed control and an acceptable yield of marketable heads with increased financial returns. Chloramben was the least effective herbicide tested and its use may not be justified under similar conditions to those of this study.     

除草剂生物筛选研究进展

生物筛选是除草剂研制开发的重要组成部分。综述了近年来除草剂生物筛选技术的发展概况,重点介绍了除草剂筛选新方法——高通量筛选技术,并指出我国在除草剂筛选方面存在的不足以及解决方案。     

光合作用抑制性除草剂的研究

文章阐述了除草剂中的几类光合作用抑制剂及其应用特点,指出了色素合成抑制剂应该是未来除草剂发展的方向。     

除草剂使用问题及对策

在除草剂使用中存在苗前用量偏低或低 ,整地质量差 ,施药过晚 ,土壤干旱 ;苗后施药期天气干旱 ,高温或喷液量过大 ,施药时期偏晚 ,混用不当 ;喷洒器械及喷洒技术落后等影响了药效 ,苗前除草剂应根据土壤有机质及质地确定用药量。采用混土施药法适期施药 ,苗后应因杂草叶龄确定施药时期。混用除草剂选择比例 ,干旱条件下施药时药液中加植物油喷雾助剂 ,选择合适的喷洒器械 ,使用前应进行调整     

Herbicide options for weed control in papaya

This paper reviews the literature on weeds and weed control in papaya. There is limited research on this topic, and nearly all of the research focuses on herbicides. Effective use of paraquat and glyphosate in papaya is dependent on avoidance of spray contact to green bark and foliage. Pre-emergence herbicide tolerance is dependent on papaya age, size and maturity, and soil type. Only one herbicide, oryzalin is shown to be tolerated by papaya immediately after transplanting. Herbicides such as diuron and oxyfluorfen with a broader spectrum of weed control generally injure young papaya, however they can be effectively used if the initial application of these herbicides is delayed until papaya attains certain size or maturity indices. There is a need for further research on weeds and weed control to improve the efficiency of papaya production     

Systemic fungicide residues in oil from field-treated olive1

A survey was carried out in Sardegna (IT) on residues in olive oil from olive treated against Spilocaea oleugina with several systemic fungicides at normal and double dose rate: benomyl, thiophanate-methyl, bitertanol, penconazole and fenarimol, all currently not registered for this use in Italy. There was a rapid decrease in benomyl, thiophanate-methyl, and bitertanol in the samples of oil from treated olives collected 0, 10, and 20 days after last treatment, but the degradation of fenarimol appeared slower. In contrast, the concentration of penconazole increased with time. It is suggested that registration of the first four compounds for use on olive would be justified.     

我国除草剂登记使用现状及存在问题

概述了我国除草剂登记和使用的基本现状,探讨了除草剂登记和使用中存在的主要突出问题,并分析了为解决这些问题可采取的有效措施或建议等。我国按《农药管理条例》的要求,农药实行登记制度。农药生产和登记随着国家工业技术的蓬勃发展,由原来主要依靠进口,主要以跨国公司的产品登记,到现在以国内企业产品登记为主,我国除草剂原药和制剂都有大量出口。但在新除草剂创制和使用中,仍然存在一些突出问题,如创制新品种能力弱、开发新技术少、除草剂药害和抗药性等问题日益突出。科学、有效的解决这些问题,将有利于保证我国农产品质量安全和我国现代农业的可持续发展。     

Determination of residues arising from fumigation practice

Ways are described in which multiple residues of fumigants can occur in practice as a result of disinfestation procedures. Developments in multi-detection methods for fumigants and their reaction products are surveyed and some possible artefacts indicated. Current experimental work on amino-acid alkylation reactions and the prospects for newer instrumentation and methods are reviewed.     

Dinitroaniline Herbicide Cross-Resistance in Resistant Setaria italica Lines Selected from Interspecific Cross with S. viridis

Breeding of herbicide-resistant foxtail millet (Setaria italica (L.) Beauv.) is desirable in modern agriculture because no selective herbicide is available for this crop. Trifluralin-resistant millet lines obtained from a interspecific cross between a resistant green foxtail (Setaria viridis (L.) Beauv.) and a foxtail millet cultivar were tested for response to five dinitroaniline herbicides in greenhouse and field experiments. The results in the greenhouse study showed that the resistant type was cross-resistant to all tested herbicides. ED₅₀ values indicated that the highest resistance was obtained with trifluralin, the resistant biotype being seven and 33 times more resistant than the parent cultivar at the emergence and seedling stages, respectively. However, the doses recommended for efficient weed control resulted in some detrimental effects on emergence and growth in the field. Strategies for use of this resistance to control weeds in millet fields are proposed. © 1997 SCI.     

Study of pesticides in waters from a chalk catchment,cambridgeshire

WRc are undertaking a long term study of pesticides in the aquatic environment. A study of the pesticides in the rain, river water and groundwater of the Granta catchment in Cambridgeshire is now in its fourth year. Preliminary results are presented and the concentrations of agricultural pesticides in environmental waters are related to the land-use within the catchment. The Granta study is incomplete but certain anomalies in pesticide occurrence can be identified. In particular, the triazines are much more prevalent in the groundwaters than their agricultural usage would lead one to expect. The limited data base gives problems with modelling the contaminant transport in groundwater. The present situation is reviewed and areas of future work necessary to fulfil the modelling needs identified. These areas of study. The historical land-use and pesticide usage; the groundwater quality data base; the pesticide transport in the unsaturated zone.     

PCB's in fish from selected waters of New York State.

PCB residues in fish from 41 stations throughout New York State were monitored in 1975. Nearly all fish contained PCB's in detectable amounts although the levels of contamination and specific Aroclor varied. The Hudson River contained the highest known PCB concentrations within the United States; levels often exceeded 100 ppm. Other waters and fish which were significantly contaminated include Lake Ontario salmonids and Cayuga Lake lake trout. Onondaga Lake, previously closed to fishing because of mercury contamination, also appears to have abnormally high levels of PCB's approaching in some instances the action level of the Food and Drug Administration, U.S. Department of Health, Education, and Welfare. Samples from marine waters generally have contaminant levels substantially below 5.0 ppm.     

日本除草剂登记与使用情况概述

本文综述日本在除草剂登记方面的法律依据、基本登记情况、登记资料要求、除草剂使用情况和存在问题等,重点介绍生测资料、残留资料方面的登记要求。日本农作物以水稻为主,整个耕地的70％都用来种植水稻,在水稻上登记的除草剂的要求最高,除了其他旱田登记的资料要求的冲绳试验、作用特性试验、适应性1试验和适应性2试验之外,试验点的数量大幅度增加．所要求的包括13个点的砂壤土试验在内总的试验报告总数在41个以上。日本在除草剂登记管理及使用方面的风险控制经验值得借鉴。     

Herbicide tank-mixing for post-emergence weed control in sugar beets

Tank-mixtures of selective herbicides were evaluated for 2 years on field-grown sugarbeets under two weed flora situations: (a) mixed floras of broad-leaved and grass weeds and (b) weed floras of broadleaves grown beyond their stages of greatest sensitivity to herbicides. In these situations single herbicides usually fail to provide satisfactory post-emergence weed control in sugarbeets. Of several tank-mixtures, which could be devised for use in the first situation, ethofurnesate + Betanal AM 11, diclofop-methyl + Betanal AM 11 and diclofop-methyl + metamitron gave synergistic phytotoxicity to sugarbeet seedlings. Synergism in weed control, becoming apparent by an accelerated appearance of the herbicidal effects, was obtained with the mixture alloxydimeton + Betanal AM 11. This mixture was not phytotoxic and appears to be the most efficient for simultaneous control of broad-leaved and grass weeds. From trials in the second situation it became apparent that the activity of metamitron, which was reduced on older weeds, could be restored by mixing with a non-phytotoxic oil or a low dose of Betanal AM 11. These mixtures should be useful when growth of sugarbeets has been retarded by carried-over herbicides, drought, frost, etc.     

喹草酮在小麦田的杀草谱及应用效果

喹草酮是一种新型对羟基苯基丙酮酸双氧化酶抑制剂类 (HPPDs) 除草剂,为明确该药剂在小麦田的应用前景,在温室内进行了3个施药时期 (播后苗前、苗后1叶期和苗后2~3叶期) 对小麦田22种杂草的活性测定和3个小麦品种的安全性测定,同时在田间开展了两年的10%喹草酮悬浮剂除草效果测定。温室试验结果表明:于播后苗前、苗后1叶期和苗后2~3叶期3个施药时期施药,喹草酮对小麦安全性高,在推荐最高施药剂量有效成分720 g/hm2条件下,3个供试小麦品种均生长正常;阿拉伯婆婆纳和麦瓶草两种阔叶杂草对喹草酮高度敏感,苗后处理的GR₅₀值(有效成分,下同) 在1.4~5.4 g/hm2之间,GR₉₀值在6.8~14.2 g/hm2之间,播后苗前土壤处理的GR₅₀值在13.3~13.8 g/hm2之间,GR₉₀值在47.7~64.0 g/hm2之间;另外,苗后施药对猪殃殃、麦家公和播娘蒿也有较好防效,GR₅₀值在7.3~98.9 g/hm2之间,且与对阿拉伯婆婆纳和麦瓶草的防效间差异显著。两年田间药效试验结果表明:喹草酮在有效成分300 g/hm2剂量下施用对小麦安全,对阿拉伯婆婆纳和麦瓶草防效高,近100%,对播娘蒿和猪殃殃防效略差,在65.3%~80.1%之间。可见,喹草酮在小麦田具有较好的应用前景,建议进一步开展复配筛选研究以扩大其杀草谱。