甲磺隆的应用技术及对后茬作物的安全性研究   总被引：3，自引：0，他引：3  

曹坳程  姚建仁  张朝贤  郭美霞  张向才 《农药学学报》2001,3(3):59-65

在冬小麦 1～ 2叶期施用甲磺隆 1.8～ 2.5 g/hm2 ,可有效防除北京地区麦田常见阔叶杂草 ,优于当前常用除草剂苯磺隆 15g/hm2 春季施用的除草效果 ,安全性与春季施用苯磺隆 15g/hm2 相当。实验室降解结果表明 ,当甲磺隆初始浓度为 6.25μg/kg以下时 ,经过215d后 ,对后茬玉米安全。研究表明 ,向日葵是甲磺隆理想的生物测定试材 ,对甲磺隆的最低检出浓度达到 0.125μg/kg,其根长抑制率与除草剂浓度有高度的相关性 ,最佳的剂量 -反应模型为 y=a+b lnx  相似文献   

井冈霉素A对水稻纹枯病菌的毒力和作用机理研究   总被引：20，自引：0，他引：20  

张穗  郭永霞  唐文华  牛灿芳 《农药学学报》2001,3(4):31-37

根据水稻纹枯病菌 Rhizoctonia solani AG- 1IA在含系列浓度井冈霉素 A马铃薯葡萄糖琼脂培养基 (PDA)上的菌丝生长速率 ,计算出药剂的毒力回归方程为:Y=3.2 30 9+0 .872 0 X,r=0 .9910 ,药剂的 EC50 =10 6 .9μg/ m L,EC75=6 34.5 μg/ m L。在含 5 0 0 μg/ m L井冈霉素 A的 PDA上水稻纹枯病菌的菌丝生长抑制率为 74 .1% ,而田间水稻植株上人工接菌的药效试验结果表明 ,5 0 μg/ m L药液喷洒后 7d和 14 d的防效即可分别达到 77.4 %和 76 .7% ,即药剂在 PDA平板上的理论抑制作用仅是田间活体植株上对病菌实际作用效果的 1/ 10。比较室内毒力和田间药效试验的结果可以看出 ,井冈霉素 A具有对病原菌和寄主植物双重作用的特性。研究首次发现 ,在室内培养基上不能有效抑制病菌生长的 1μg/ m L的井冈霉素 A可以在水稻植株未喷药部位产生防御水稻纹枯病的作用 ,且能够持续诱导植物防御反应相关酶——过氧化物酶 (PO)和苯丙氨酸解氨酶 (PAL)的活性增高,表明该药剂可以激发水稻抗性防卫反应的表达。  相似文献   

苏云金芽孢杆菌菌种保藏     

戴莲韵 《林业科学》1996,32(6):516-521

采用砂土管和滤纸片两种保藏方法，对分属３１个亚种的６１株有代表性的苏云金芽孢杆菌经过１－２３年保存后的菌体存活情况，形态特征及对林业主要害虫舞毒蛾幼虫的杀虫活性进行了试验，并对苏云金芽孢杆菌５个亚种的标准菌株和保存不同年限后的１１项生理生化特性及酯酶型进行了测定。  相似文献   

Compartmentalization response of two clones of hybrid-poplar     

K. T. Smith  W. C. Shortle 《Forest Pathology》1993,23(1):11-17

A 14-day bioassay indicated the effectiveness of Compartmentalization evident 24 months following wounding of two clones of hybrid-poplar. The boundary pattern adjacent to columns of wound-initiated discoloration indicated that column boundary layer formation was not the sole determinant for the effectiveness of Compartmentalization.  相似文献   

Soil properties and nitrogen availability in silvopastoral plantings of Acacia melanoxylon in North Island, New Zealand     

I.L. Power  B.S. Thorrold  M.R. Balks 《Agroforestry Systems》2003,57(3):225-237

Acacia melanoxylon, a N₂-fixing timber tree occurring naturally in eastern Australia, is now promoted as a component of silvopastoral systems; but the interaction of the tree with pasture and soils has not been adequately studied. This study investigated the effects of Acacia melanoxylon on soil nitrogen (N) levels, N availability, soil pH, bulk density, organic carbon, C:N ratios and soil moisture in three separate silvopastoral sites with contrasting soil types in the North Island of New Zealand. At each site four tree stocking rates were studied (0, 500, 800, and 1700 stems ha^–1). The trees were nine years old at the time of the study. Soil samples from each study site were taken once at three depths (0 to 75 mm, 75 to 150 mm, and 150 to 300 mm), with three replicates per tree stocking rate. Soil analyses showed that although there were differences between soil types, few statistically significant differences occurred due to tree stocking rate. A greenhouse pot trial growing ryegrass (Lolium multiflorum L. cv. Concord) in soil from the A horizon of each soil type from under the trees and the open pasture found that ryegrass yield, N uptake and N supply increased with increasing tree stocking rate. Increased N supply under the trees, coupled with greater soil moisture compared to the open pasture may have accounted for the higher pasture yield under Acacia melanoxylon compared to non dinitrogen fixing tree species. This study suggested that Acacia melanoxylon in a silvopastoral system had the potential to increase soil N availability.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

Pb²⁺对甘肃纹党种子萌发和幼苗生理特性的影响     

叶文斌  樊亮  贠汉伯 《西北农业学报》2012,21(12):142-148

以甘肃道地中药材纹党(Codonopsis pilosula)为对象，通过室内培养试验，研究不同浓度10^-6、10^-5、10^-4、10^-3 mol/L Pb²⁺处理对纹党种子萌发、幼苗生长以及生理特性的影响，为探究Pb²⁺污染对纹党品质的影响提供依据。结果表明，Pb²⁺对纹党种子吸胀过程中相对吸水量的增加有抑制作用，随着Pb²⁺浓度的提高，党参种子的萌发率、萌发指数、幼苗生长及根尖微核和有丝分裂率变化，表现出先升高后降低的趋势；低浓度的Pb²⁺处理能够促进叶绿素的形成，高浓度则抑制叶绿素形成；可溶性糖、游离脯氨酸和丙二醛含量，随Pb²⁺浓度的升高而增加；Pb²⁺对SOD、POD和CAT活性有较强的抑制作用。可见，生物测定结果大多达到显著差异水平。  相似文献   

黄瓜子叶法筛选蔬菜灰霉病杀菌剂的研究   总被引：20，自引：1，他引：20  

李树正  包如棣 《华北农学报》1991,6(3):94-99

研究了以“黄瓜子叶法”为特征的蔬菜灰霉病杀菌剂的筛选模式.采用本方法标准药剂速克灵、扑海因获得很好的重复性;接种最适宜的分生孢子浓度为1×10~5/ml;菌丝菌龄对实验结果有明显的影响;采用浸渍法或喷雾法进行药剂处理对实验结果影响不大,但前者操作似更简单.供试乳化剂、溶剂中,除农乳700号及二甲基甲酰胺之外,对蔬菜灰霉病菌均无明显的影响.  相似文献   

A new plant-based bioassay for aquatic sediments     

Ute?FeilerEmail author  Ilona?Kirchesch  Peter?Heininger 《Journal of Soils and Sediments》2004,4(4):261-266

Background, Goal and Scope  To date, standardised bioassays for the assessment of the ecotoxicological potential in sediments and dredged material use test organisms like bacteria, algae and crustaceae. This paper presents the development and application of a novel sediment contact test (whole sediment) withMyriophyllum aquaticum, a representative of rooted aquatic macrophytes. The aim of the present study is to demonstrate the value of a sediment contact test with rooted macrophytes as a supplement to existing test batteries in order to improve the assessment of sediment toxicity. Methods  The newly developed sediment contact test withMyriophylhim aquaticum was applied to natural whole sediments. For performing the test, whorls ofMyriophyllum aquaticum were directly planted in the native sediment and incubated in the light at 24°C (cf. section results and discussion). The end points of the test were the number of the shoots and the fresh weight of the whole plants. The duckweed growth inhibition test withLemna minor according to ISO/DIS 20079 was performed in pore waters from sediment samples. The results of the sediment contact test withMyriophyllum aquaticum were compared with each other and with those of the aquatic duckweed test. Results and Discussion  A test protocol for the new plant-based sediment contact test using the aquatic plantMyriophyllum aquaticum as an indicator was developed. The best control sediment proved to be the OECD sediment (OECD 207). A test period of 10 days appeared to be sufficient for the test. The increase of biomass and the derived growth rate were found to be the most suitable evaluation parameters. The growth behaviour ofMyriophyllum aquaticum differed depending on the origin of sediments. Therefore, plant-affecting contamination, that is bound in sediments, was indicated. Conclusions  The novel sediment contact test withMyriophyllum aquaticum can indicate phytotoxic effects in sediments. Therefore, it allows a better assessment of the overall-toxicity in whole sediments. Recommendations and Outlook  The sediment contact test withMyriophyllum aquaticum is a valuable tool for the evaluation of the ecotoxicological risk potential of waters and sediments. It should become a complement to a standardised test battery generally used for the assessment of sediment toxicity.  相似文献   

Protozoan bioassays of soil amended with sewage sludge and heavy metals,using the common soil ciliate Colpoda steinii     

T. A. Forge  M. L. Berrow  J. F. Darbyshire  A. Warren 《Biology and Fertility of Soils》1993,16(4):282-286

The common soil protozoan Colpoda steinii was used to study the toxicity of sulphate solutions of Ni, Cd, Cu, and Zn. The growth of C. steinii was reduced by 50% in the presence of 0.10, 0.22, 0.25, and 0.85 mg litre^-1 of Ni, Cd, Cu and Zn, respectively, during 24 h of incubation at 25°C, as calculated from a regression analysis of probit-transformed data. The same growth assay was used to assess the toxicity of soil solution extracted by centrifugation from soil samples of field plots of a grass/clover ley on a sandy loam treated with sewage sludge spiked with additional Cd, Cu, Cr, Ni, Pb, or Zn at concentrations either equivalent to or twice the limits for heavy metals recommended in recent EC guidelines (Commission of European Communities directive 86/278/EEC). The toxicity of these soil solutions varied with the season of the year. None of the soil solutions extracted in winter (February 1991) inhibited the growth of C. steinii. In summer (July 1991), the growth was reduced in solutions extracted from plots that were amended with sludge plus additional Zn or Ni at twice the maxima recommended by the EC. The changes in toxicity to C. steinii of the soil solutions between February and July were positively correlated with increases in heavy metal concentrations of Zn and Ni between winter and summer. These preliminary results suggest that regular protozoan bioassays may be used to monitor the biological availability of heavy metals in soils, especially when combined with other microbial assays and with chemical analyses of soil solutions.  相似文献   

螺虫乙酯对烟粉虱的防治效果评价   总被引：8，自引：0，他引：8  

谢文  吴青君  徐宝云  王少丽  张友军 《中国蔬菜》2011,1(14):69-73

采用室内毒力测定与田间试验相结合的方法,研究了螺虫乙酯（Movento）对烟粉虱的防治效果。室内毒力测定结果表明：96 %螺虫乙酯原药对烟粉虱卵和若虫都具有非常高的杀虫活性,LC50分别为18.91 mg?L-1和14.97 mg?L-1,与对照95 %吡虫啉没有显著差异|但对烟粉虱成虫的杀虫效果并不十分理想,LC50达到了453.34 mg?L-1,且显著高于对照95 %吡虫啉。田间试验结果表明：24 %螺虫乙酯悬浮剂（SC）对烟粉虱有良好的防效和持效性,且螺虫乙酯与Biopower（助剂）混用的防效明显优于螺虫乙酯单独使用的效果|螺虫乙酯与0.2 %〔0.24 g?（667 m2）-1〕Biopower混用,药后1～28 d对烟粉虱的防效分别为64.91 %～66.92 %、82.00 %～82.59 %、88.11 %～89.97 %、89.99 %～93.94 %和91.10 %～93.56 %。  相似文献