农达对水葫芦象甲的影响

用４１％农达加水分别稀释３０、１００、３００、１０００和３０００倍,在室内测试了对水葫芦象甲的影响。结果表明,象甲卵和初孵幼虫直接接触药液对孵化率和化蛹率没有明显的影响。将药液直接喷施于成虫体表后再饲喂新鲜健康的叶片对象甲存活没有明显的影响。用不同浓度药液处理的叶片饲喂象甲成虫１月后,存活率分别为１０．０％、４５．０％、４２．５％、６６．７％和７７．５％,对照为７２．５％。室外种群动态试验发现,用１００倍以下药液处理有象甲成虫和幼虫的水葫芦小区３个月后,水葫芦和象甲全部死亡;而用３００倍以上农达处理的小区内象甲仍保持一定的种群数量。本项研究表明低浓度农达对象甲比较安全,可与象甲配合控制水葫芦。     

水葫芦象甲对水葫芦的生物防治效应

通过在室内塑箱释放专食性天敌昆虫——水葫芦象甲以控制水葫芦的研究。初步探明了水葫芦象甲不同释放密度对水葫芦植株生长的影响、控制效果以及适宜的水葫芦象甲释放密度,为水葫芦生物防除的推广应用提供了一定的理论基础。     

水葫芦象甲对外来杂草水葫芦的控制效果

外来植物水葫芦是目前我国南方危害最为严重的水生杂草。本文研究了野外释放从国外引进的专食性天敌昆虫控制水葫芦的效果。1996年8月在浙江温州面积为1372m^2、水葫芦覆盖率达100％的河道上释放1000头象甲，放虫2年后，水葫芦植株长势明显受到抑制，但仍有75％的水面被覆盖。防效仅为25％，3年后，发展迅速，效果十分显著，99％的水葫芦被清除。随着放虫区水葫芦数量和长势的减弱，象甲开始向四周扩散，首先扩散到紧邻放虫区面积为3000m^2的河道上，并在1999年4月将70％的水葫芦清除；同年12月发现，从放虫区沿河道向下游20km，均可发现象甲。     

用不同日龄水葫芦叶片饲养对水葫芦象甲的影响

水葫芦(Eichnornia crassipes(Mart)Solms-Laub)是目前世界上危害最严重的多年生水生杂草(私人通信).近年来大面积覆盖我国南方的很多水体,带来严重的生态、经济和社会危害[1].为控制水葫芦的蔓延为害,中国农科院1995从美国和阿根廷引进了两种天敌昆虫(Neochetina eichhorniae和N.brachi),有效地抑制了已释省区水葫芦的生长[2].国外曾就水葫芦叶龄对N.eichhorniae卵和幼虫在植株体内分布的影响进行过研究[3],本文就用不同日龄水葫芦叶片饲养对象甲的影响进行了研究,为人工饲养象甲提供科学依据.     

水葫芦象甲的生物学及其寄主专一性

在室温 2 5～ 2 8℃的养虫室内 ,水葫芦象甲雌成虫寿命最长可达 1 6 1d ,最大卵量为 1 0 91粒。产卵期为 2 0～ 1 59d。卵主要产在叶柄内。幼虫孵化后在叶片内和叶柄中取食 ,并向植株基部钻蛀。幼虫期 30～ 4 0d。老熟幼虫在活的水葫芦植株根部化蛹 ,蛹期 2 5～ 30d。在温州自然条件下 ,象甲年发生 2代 ,并有明显的世代重叠现象。以成虫和幼虫越冬。利用 2 3科 4 6种植物进行的寄主专一性测定发现 ,该象甲只为害水葫芦 ,可安全用于水葫芦的生物防治     

三种化学除草剂对水葫芦象甲的影响

室内外就草甘膦、克芜踪、农得时３种除草剂对水葫芦象甲卵、幼虫、蛹和成虫的影响进行了初步测试。象甲卵直接接触３种除草剂药液和清水对照后,孵化率分别为８３．３％、９３．３％、９２．２％和９５．６％;处理有卵植株叶片后,卵的孵化率分别为９０．０％、５３．４％、８５．６％和９３．６％。３种除草剂对初孵幼虫存活和蛹的羽化影响不大。但用克芜踪和农得时处理的叶片喂食象甲后,成虫产卵量分别为０．１７和０．２７粒／（对ｄ－１）,取食量分别为１０．８０和８．７０个取食斑／（对ｄ－１）,明显低于对照的产卵量１．１４粒和取食量１５．４０个／（对ｄ－１）,而草甘膦处理后象甲产卵量为１．１４粒／（对ｄ－１）,取食斑为１６．５０个／（对ｄ－１）,与对照差异不显著;克芜踪处理后７０天,象甲全部死亡,而草甘膦、农得时和对照的存活率分别为９２．５％、９５．０％和９７．５％。综合比较结果,３种除草剂对象甲的毒性影响依次为克芜踪＞农得时＞草甘膦     

水葫芦的综合利用

该文简述了水葫芦的生物学特性,详细介绍了这种水生植物在造纸、肥料、饲料、食用和药用以及污水治理等方面的应用现状与前景,并提出了水葫芦利用过程中须要注意的问题。     

巴佰金+农达防除苹果园杂草效果研究

采用70％巴佰金水分散粒剂和41％农达混用,再加入不同种类助剂,防除苹果园主要杂草,特别是对农达已经产生较强耐药性的阔叶杂草的防除效果、速效性及持效期的影响进行了研究。     

稻象甲和稻水象甲

稻象甲(Fchironmus squameusBillberg)和稻水象甲(Lissorhoptrus o-ryzophilus Keschel)是全世界为害水稻的两种重要害虫。稻水象甲为我国进口植物检疫对象,国内目前尚未见有分布报道。本文结合国外资料,对两虫的生物学及防治措施进行了比较研究。稻象甲主要分布我国、     

化学除草剂对恶性杂草水葫芦的控制效果

水葫芦[Eichhornia crassipes(Martius)Solms-Laubach]分布于我国南方10余省市,给农业、水产养殖业、旅游业和周围环境带来了极大的危害。采用综合治理措施、发挥生物和化学防治的优势可以达到快速、有效、持续控制的目的。本文报道了4种除草剂对水葫芦的控制效果。     

水葫芦花期不同部位的资源性化学成分分析与评价

分别采用减重、电感耦合等离子体-原子发射光谱法(ICP-AES)、凯氏定氮法和BCA试剂盒法、硝酸铝-分光光度法以及超高效液相-质谱联用HILIC-UPLC-TQ-MS/MS方法,对水葫芦花期不同部位水分和灰分、重金属、粗蛋白、总黄酮类、核苷类、氨基酸类成分的组成及含量进行分析评价。结果表明水葫芦花期须根、短缩茎、匍匐茎、叶柄、叶片、花序中水分含量分别为93.67%、96.34%、97.13%、96.65%、90.85%、96.03%,总灰分和酸不溶性灰分含量分别为25.83%、24.24%、26.32%、17.33%、18.64%、17.16%和6.83%、6.19%、7.36%、5.24%、4.97%、4.85%;砷、镉、铅含量之和分别为29.77、14.01、11.67、12.36、140.43、20.85 mg/kg;2种方法测得的粗蛋白含量分别为7.79%、7.17%、10.21%、8.29%、17.67%、18.23%,4.64%、3.95%、7.83%、5.14%、13.74%、14.02%;总黄酮类含量分别为2.81%、4.18%、3.38%、3.04%、8.29%、4.17%;总核苷类成分含量分别为0.46%、0.57%、0.64%、0.29%、1.04%、1.52%;总氨基酸类成分含量分别为0.21%、0.25%、0.55%、0.21%、1.44%、1.37%。水葫芦花期各部位均含有丰富的资源性化学成分,叶片和花序中粗蛋白、总黄酮类、核苷类、氨基酸类成分含量在各部位中最高,具有潜在的药用和营养保健价值。本研究结果可为水葫芦的资源化利用提供科学依据。     

Random amplified polymorphic DNA markers reveal low genetic variation and a single dominant genotype in Eichhornia crassipes populations throughout China

Genetic variation within and between 34 populations of Eichhornia crassipes (water hyacinth) in China was surveyed using random amplified polymorphic DNA (RAPD) markers. A total of 1009 individuals were analysed, for which 12 RAPD primers amplified 69 reproducible bands, with 22 (32%) being polymorphic. The percentage of polymorphic loci (p) within a population ranged from 4.4% to 17.4%, and the mean Nei's gene diversity (H_e) was 0.046 ± 0.0145, indicating a low genetic diversity of E. crassipes in China. Each population contained at least four RAPD phenotypes (genotypes), and the same particular genotype was invariably dominant in all the populations sampled. The mean proportion of distinguishable genotypes was 0.29. Analysis of molecular variance revealed a large proportion of genetic variation (83.9%) residing within populations and a slightly larger proportion (88.1%) within localities, indicating a low genetic differentiation of E. crassipes populations, both locally and regionally. Human-mediated dispersal, vigorous clonal growth, and a generally low level of sexual reproduction were thought to be responsible for such a pattern of genetic structure.     

Successful biological control of water hyacinth (Eichhornia Crassipes) by Neochetina eichhorniae (Coleoptera: curculionidae) in Bangalore,India

Abstract

Water hyacinth is the most serious aquatic weed in India, infesting more than 200000 ha of water surface. Successful biological control of this weed was achieved in a fully infested tank covering 20 ha at Bangalore. More than 95% of the infestation was cleared within 32 months by releases of Neochetina eichhorniae Warner. The insect also spread along a water channel and controlled water hyacinth infesting a nearby tank. Drying up of the tank after the insect population had spread throughout and increased to 3.1 adults/plant hastened weed control. Fresh plants emerging after rains were suppressed by the residual population of insects. N. eichhorniae along with N. bruchi Hustache is being supplied to centres throughout the country for multiplication and releases. Sustained efforts with these insects holds out promise of control of water hyacinth in India.     

外来恶性杂草——空心莲子草、水葫芦的分布调查及防控建议

从20世纪60年代起,尤其是对外改革开放以来,随着国际贸易交往,国外引种、人员交流的日益频繁,为外来影响农业的恶性杂草传入创造了便利条件,使其不断地向新地域扩散蔓延,繁殖生存为害。     

Comparison of the effect of Roundup Ultra 360 SL pesticide and its active compound glyphosate on human erythrocytes

The effects of exposure of human erythrocytes to different concentrations of Roundup Ultra 360 SL and its active compound glyphosate were studied. We studied hemolysis after 1, 5, and 24 h incubation; lipid peroxidation, hemoglobin oxidation, the level of reduced glutathione, and the activity of catalase after 1 h. Human erythrocytes were incubated with 100-1500 ppm (100 μg/ml erythrocytes at 5% hematocrite) Roundup Ultra 360 SL and glyphosate. We have found that after 1 h of incubation only Roundup Ultra 360 SL increased the level of methemoglobin, products of lipid peroxidation at 500 ppm and hemolysis at 1500 ppm [Curr. Top. Biophys. 26 (2002) 245], while its active compound glyphosate increased the level of methemoglobin and the level of lipid peroxidation at much higher dose—1000 ppm. At the same time hemolysis was observed to only at the highest dose of glyphosate (1500 ppm) and the longest time of incubation (24 h). Both Roundup Ultra 360 SL and glyphosate did not cause statistically significant changes in the level of GSH, but increased the activity of catalase. Roundup Ultra 360 SL provokes more changes in the function of erythrocytes than its active substance glyphosate, which is probably a result of the properties of additives. Taking into account the limited accumulation of Roundup Ultra 360 SL and glyphosate in the organism as well as the fact that the threshold doses which caused changes in erythrocytes for Roundup Ultra 360 SL were only 500 and 1000 ppm for glyphosate, one may conclude that this pesticide is safe towards human erythrocytes.     

Survey and Assessment of the Natural Enemies of Water Hyacinth,Eichhornia crassipes

Abstract

In northern Queensland, the addition of 2,4,5‐T butyl ester was found to be unnecessary to maintain the control of Echinochloa colona (L.) Link and Cyperus Iria L. In dry seeded rice when propanil rates were reduced below the registered rate of 4 kg a.i. ha^?1. Adequate weed control was obtained with 1.3 kg a.i. ha^?1 propanil alone. No adverse effects on rice yield were found with any of the propanil × 2,4,5‐T treatments. Low rates of propanil, 1.3 and 0.72 kg a.i. ha^?1, compared favourably with pre‐emergence treatments of thiobencarb, butachlor, oxyfluorfen and pretilachlor (plus a safener) when weed yields were low. Where water management was poor and Ischaemum rugosum Salisb. was the dominant weed, oxyfluorfen applied pre‐emergence at 0.96 kg a.i. ha^?1 produced a higher rice and a lower weed yield than the low rates of propanil. In three of the five experiments, weed growth was insufficient to depress rice yields significantly.     

Integrated control of potato late blight: predicting the combined efficacy of host resistance and fungicides

Integrating cultivars that are partially resistant with reduced fungicide doses offers growers an opportunity to decrease fungicide input but still maintain disease control. To use integrated control strategies in practice requires a method to determine the combined effectiveness of particular cultivar and fungicide dose combinations. Simple models, such as additive dose models (ADM) and multiplicative survival models (MSM), have been used previously to determine the joint action of two or more pesticides. This study tests whether a model based on multiplicative survival principles can predict the joint action of fungicide doses combined with cultivars of differing partial host resistance. Data from eight field experiments on potato late blight (Phytophthora infestans) were used to test the model; the severity of foliar blight was assessed and scores used to calculate the area under the disease progress curve (AUDPC). A subset of data, derived from the most susceptible cultivar, King Edward, was used to produce dose–response curves from which parameter values were estimated, quantifying fungicide efficacy. These values, along with the untreated values for the more resistant cultivars, Cara and Sarpo Mira, were used to predict the combined efficacy of the remaining cultivar by fungicide dose combinations. Predicted efficacy was compared against observations from an independent subset of treatments from the field experiments. The analysis demonstrated that multiplicative survival principles can be applied to describe the joint efficacy of host resistance and fungicide dose combinations.     

Herbicidal potential of allelochemicals from Lantana camara against Eichhornia crassipes and the alga Microcystis aeruginosa

In the field, the growth of the aquatic weed Eichhornia crassipes and the alga Microcystis aeruginosa may be inhibited by fallen leaves of Lantana camara. This study showed that extracts of L. camara leaves and their fractions reduced the biomass of E. crassipes and M. aeruginosa within 7 days under laboratory conditions. Two fractions with highly inhibitory activity from the extract were isolated and subsequently identified as the pentacyclic triterpenoids, lantadene A and lantadene B. Both compounds significantly inhibited E. crassipes and M. aeruginosa growth, even at a low concentration. At all concentrations tested, their inhibitory activities were much higher than that of salicylic acid, a putative allelochemical from L. camara. The results indicated that the predominant allelochemicals involved in L. camara against either E. crassipes or M. aeruginosa are not phenolic acids, but lantadene A and lantadene B. Field trials showed that released levels of lantadene A and lantadene B were significantly correlated with amounts and decomposition periods of L. camara leaves floated in water. The amount released from 5 kg L. camara leaves was over the inhibition threshold of both E. crassipes and M. aeruginosa and reached a maximum at days 15–20. This study suggested that allelochemicals of L. camara could potentially be used to improve the management of weeds and algae in aquatic systems.