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1.
Winegrape is an important perennial crop in California, USA. Each year California winegrape farming consumes about 20 million
kilograms of pesticides that have been a pollutant source to the fresh water systems of the state. The variation of pesticide
use among winegrape growers has been significant. It has been observed that some growers have developed effective ways to
reduce pesticide use, yet control pests efficiently to ensure harvest. Identification of the growers with low and high pesticide
use is very helpful to extension programs that aim on reducing pesticide environmental risk. In this study, an index approach
is proposed to quantitatively measure pesticide use intensity at grower level. An integrated pesticide use index is developed
by taking pesticide quantity and toxicity into account. An additive formula and a multiplying formula were used to calculate
the pesticide use index, i.e., PUI and PUIM. It was found that both PUI and PUIM were capable of identifying the low and high
pesticide users while PUI was slightly more conservative than PUIM. All pesticides used in California winegrape farming were
taken into account for calculating the indices. Madera County, one of the largest winegrape producers in California, was taken
as an example to test the proposed approach. In year 2000, among the total 208 winegrape growers, 28 with PUI≤10 and 34 with
10<PUI≤20 were identified as low pesticide users who were characterized with both low quantity and low toxicity of pesticide
use. Most of the growers had small-sized vineyards, i.e., one field and small planted areas. Furthermore, they had very low
pesticide use intensity, used only 1–2 types of pesticides (mainly fungicides), applied few pesticides (1–3 only), and emphasized
the use of low toxicity compounds. Meanwhile, 19 growers with PUI>60, identified as high pesticide users, had large-sized
vineyards, i.e., more fields and large planted areas. They used all types of pesticides and many compounds, which indicated
that their pest controls heavily depended on pesticides rather than on-farm management. Through the case study, the proposed
approach proved to be useful for analyzing the growers’ pesticide use intensities and interpreting their pesticide use behaviors,
which led to a new start point for further investigation of searching ways to reduce pesticide environmental risk. 相似文献
2.
An incubation study was conducted to investigate the effects of metsulfuron-methyl herbicide on the soil microbial biomass
in loamy sand soil. The herbicide was applied to the soil at four concentrations: control, 0.01, 0.10, and 1.00 μg·g−1 soil. Determinations of microbial biomass-C and microbial biomass-N contents were carried out 1, 3, 5, 7, 10, 15, 25, and
45 days after herbicide application. In comparison to untreated soil, the microbial biomass-C and biomass-N decreased significantly
in soils treated with herbicide at concentrations of 0.1 and 1.0 μg·g−1 soil within the first 7 days of incubation. The application of metsulfuron-methyl herbicide to the soil reduced the Cmic/Corg and Nmic/Ntotal percentages, which decreased with increasing application rate of metsulfuron-methyl herbicide. Compared to the untreated
control, a marked increase in the microbial biomass C: N ratio was observed in the herbicide treated soil. This effect was
transitory and was significant only at the higher rates of metsulfuron-methyl.
Project supported by NSFC (No. 49871044) and the Laboratory of Materials Cycling in Pedosphere, Academia Sinica. 相似文献
3.
草甘膦对3种滩涂动物的急性毒性及安全评价 总被引：2，自引：0，他引：2
采用静水法和半静水法检测不同浓度下除草剂草甘膦对缢蛏、可口革囊星虫和大弹涂鱼的急性毒性,并根据·化学农药环境安全评价试验准则·中农药的毒性分级,评价了草甘膦对三种滩涂生物的安全性．结果显示：草甘膦对于缢蛏、可口革囊星虫和大弹涂鱼的96 h LC50分别为233．60,1267．00,1068．00 mg·L－1,均属于低毒;安全浓度分别为23．36,126．70,106．80 mg·L－1,毒性顺序为缢蛏＞大弹涂鱼＞可口革囊星虫． 相似文献
4.
A laboratory incubation experiment was conducted to study the effect of copper as cupric sulfate (CuSO4.5H2O), and lead as lead acetate (Pb (OAc)2) on the size of the microbial biomass in red soil. The metals were applied, separately at six different levels: Cu at 50,
100, 200, 300, 400, and 600 μg·g−1 soil and Pb at 100, 200, 400, 600, 800, and 1000 μg·g−1 soil. In comparison to uncontaminated soil, the microbial biomass carbon (Cmic) and biomass nitrogen (Nmic) decreased sharply in soils contaminated with Cu and Pb. The microbial biomass C:N ratio in the metal contaminated soil was
observed to be considerably higher than that in untreated control. Between the two tested metals, Cu displayed greater biocidal
effect on microbial biomass carbon and nitrogen than Pb, showing their relative toxicity in the order: Cu≫Pb.
Project (No. 49671050) supported by National Natural Science Foundation of China.
Wa’el Mohamad—Former Ph. D. Student of Zhejiang University and is working in Ministry Of Agriculture (P. O. box. 2099), Amman,
Jordan. 相似文献
5.
吴瑛 《岳阳职业技术学院学报》2011,26(5):67-71
杀菌剂是现代农药的一个重要组成部分,利用它,人们可以把作物的生长控制在对人有利的方向。为了寻找并筛选具有较高杀菌活性的化合物,将具有优良生物活性的1,3,4-噁二唑结构引入化合物中,合成20个目标化合物。本文采用离体活性测试法对目标化合物进行杀菌活性测试,获得对部分植物病原真菌具有较高活性和应用价值的杀菌剂。 相似文献
6.
Toxicity of cadmium to soil microbial biomass and its activity：Effect of incubation time on Cd ecological dose in a paddy soil 总被引：4，自引：0，他引：4
INTRODUCTION Cadmium (Cd) is ubiquitous in the human en-vironment and has been recognized as one of the mostdeleterious heavy metal pollutants (Robards andWorsfold, 1991; Christine, 1997). It may easily movefrom soil to food plants through root absorption andaccumulate in their tissues (Oliver, 1997). In this way,Cd may enter the food chain and affect human health(Adriano, 1986). Among many heavy metals pollut-ing soil, Cd is of concern because of its potentiallyharmful effects on… 相似文献
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8.
植物源杀虫剂的研究进展 总被引：3，自引：0，他引：3
论述了植物源杀虫剂的研究历史和发展现状,对几种开发较为成功的杀虫成分作了初步分析,展望了新世纪植物源农药的发展前景,指出产业化发展植物源农药的方向和途径。 相似文献
9.
用不同浓度的乙草胺对小麦幼苗染毒处理,检测小麦幼苗内的过氧化氢酶（CAT）活性的变化．结果表明：各实验组随染毒时间的延长,在不同质量浓度乙草胺的胁迫下,小麦幼苗细胞的CAT活性呈现出不同的变化趋势．在低质量浓度时,CAT活性表现出先下降后升高,再降低的特点;在中质量浓度时,CAT活性表现出先升高后下降,再升高的特点;在高质量浓度时,CAT活性表现出缓慢下降的特点．在乙草胺的胁迫下,小麦幼苗内cAT活性与对照组相比,差异极显著（P〈0．01）．结论：乙草胺对小麦幼苗有较强的毒性效应． 相似文献
10.
农药残留对人体健康的危害效应及毒理机制 总被引：1，自引：0，他引：1
有机磷农药和有机氯农药是农药残留的两大类型。探讨这两类农药残留对人体健康的危害效应及其毒理机制,提出一些相关防治农药残留的建议。 相似文献
11.
土壤含水量对浑水入渗能力的影响 总被引：1，自引：0，他引：1
土壤含水量对浑水入渗能力产生明显影响,土壤含水量由小变大,浑水入渗能力减小;3个入渗参数随土壤含水量的增大而减小。研究结果对于指导浑水入渗及引洪补源具有重要意义。 相似文献
12.
食品农药残留分析方法的现状与展望 总被引：1，自引：0，他引：1
曾琪 《四川职业技术学院学报》2006,16(3):119-121
由于农药及其降解产物在环境里引起的危害问题日益受到人们的重视,因而加强环境与食品中农药残留的检测对于保护人类健康、保护环境具有非常重要的现实意义。由于我国常用的农药种类繁多,结构差别很大,而农药残留分析需要对超标的样品给出准确的定性、定量,因此,不可能有一种分析方法适用于所有的农药和样品。本文综述了食品里农药残留的常规分析方法及其最新的进展,提出了农药残贸留分析过程的基本准则及分析方法的发展方向． 相似文献
13.
柴凤瑞 《唐山师范学院学报》2001,23(2):60-61
设计了杀虫剂TH－6040对扬天社蛾和国槐尺蠖两食叶害虫的毒力测定和药效试验。试验结果表明：杀虫剂TH－6040对扬天社蛾的卵有较强的生物活性；该药剂对两食叶害虫的幼虫有较强毒力，是既经济又有效的常用农药。 相似文献
14.
Jan Douglas-Morris Helen Ritchie Catherine Willis Darren Reed 《Anatomical sciences education》2021,14(3):287-295
Multiple-choice (MC) anatomy “spot-tests” (identification-based assessments on tagged cadaveric specimens) offer a practical alternative to traditional free-response (FR) spot-tests. Conversion of the two spot-tests in an upper limb musculoskeletal anatomy unit of study from FR to a novel MC format, where one of five tagged structures on a specimen was the answer to each question, provided a unique opportunity to assess the comparative validity and reliability of FR- and MC-formatted spot-tests and the impact on student performance following the change of test format to MC. Three successive year cohorts of health science students (n = 1,442) were each assessed by spot-tests formatted as FR (first cohort) or MC (following two cohorts). Comparative question difficulty was assessed independently by three examiners. There were more higher-order cognitive skill questions and more of the course objectives tested in the MC-formatted tests. Spot-test reliability was maintained with Cronbach’s alpha reliability coefficients ≥ 0.80 and 80% of the MC items of high quality (having point-biserial correlation coefficients > 0.25). These results also demonstrated guessing was not an issue. The mean final score for the MC-formatted cohorts increased by 4.9%, but did not change for the final theory examination that was common to all three cohorts. Subgroup analysis revealed that the greatest change in spot-test marks was for the lower-performing students. In conclusion, our results indicate spot-tests formatted as MC are suitable alternatives to FR tests. The increase in mean scores for the MC-formatted spot-tests was attributed to the lower demand of the MC format. 相似文献
15.
Liujia SHI Fangfang YANG Yanyan XU Shoufeng WANG 《Journal of Zhejiang University. Science. B》2021,22(3):204-213
Acetylcholinesterase(AChE) is a key enzyme used to detect organophosphorus pesticide residues by the enzyme inhibition method.An accidental discovery of a mutant strain with AChE activity was made in our laboratory during the process of AChE expression by Pichia pastoris.The pPIC9 K-Drosophila melanogaster acetylcholinesterase(DmAChE)-like expression vector was constructed by codon optimization of this mutant strain,which was transformed into P.pastoris GS115,and positive clones were selected on yeast peptone dextrose(YPD) plate with G418 at 4.0 mg/mL.The GS115-pPIC9 K-DmAChE-like strain was subjected to 0.5% methanol induction expression for 120 h,with a protein band at 4.3 kDa found by the tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) pattern of the fermentation supernatant.After preliminary purification by ammonium sulfate precipitation,the enzyme activity was detected to be 76.9 U/(mL·min).In addition,the pesticide sensitivity test proved that DmAChE-like is selective and sensitive to organophosphorus pesticides. 相似文献
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17.
微生物源杀虫剂的研究进展概况 总被引：2，自引：0，他引：2
黄敏 《广东轻工职业技术学院学报》2005,4(4):12-15
总结了近几年来微生物源杀虫剂的研究成果,逐一介绍其作用机理和目标物,并从机理出发分析其对人类和环境的影响,列举了各种微生物源杀虫剂的生产方法,通过与化学杀虫剂的比较,展望了微生物源杀虫剂的应用前景。 相似文献
18.
黄晓梅 《十堰职业技术学院学报》2007,20(5):89-91
分析5种高毒农药的发展的基本情况以及高毒农药禁用的必要性与可行性,及其禁用高毒农药应采取的对策。最后提出了相关的结论与建议。 相似文献
19.
对宿州市近郊农田土壤中4种重金属元素Cu、Pb、Zn和As的含量、空间分布及来源状况进行了分析,并采用综合指数法对其农田土壤重金属污染水平进行了评价。结果发现:宿州市近郊农田土壤中Cu、Pb、Zn的平均含量低于安徽省土壤背景值,As高于背景值;Pb和Zn的含量空间分布受交通污染源的影响,Cu与生活垃圾及废弃物的排放有关,As则来源于农药产品的使用;近郊农田土壤重金属为轻污染水平,以As污染最严重。 相似文献
20.
国内外生物农药概况与发展趋势 总被引：1，自引：0，他引：1
分析了国外抗生素农药、细菌杀虫剂、微生物除草剂、微生物农药及国内生物杀虫剂、生物除草剂、转基因植物类农药的发展状况.从低碳、清洁方面看,生物农药具有良好的市场前景. 相似文献