26种杀菌剂对橡胶粉孢的毒力测定

开展孢子萌发试验和室内盆栽试验测定26种杀菌剂对橡胶树白粉病菌的毒力.结果表明:在抑制病原菌孢子萌发的能力方面,吡唑醚菌酯、唑胺菌酯、氟菌螨酯、醚菌酯、烯肟菌胺、唑菌酯、氟菌唑、嘧菌酯、氟环唑、四氟醚唑、氟硅唑、乙嘧酚强于三唑酮,苯醚甲环唑、福美双与三唑酮相当;在抑制菌丝生长的能力方面,氟菌唑、唑菌酯、氟菌螨酯强于三唑酮,氟环唑、唑胺菌酯、氟硅唑、吡唑醚菌酯接近三唑酮,四氟醚唑稍弱于三唑酮.氟菌唑、唑菌酯、氟菌螨酯、氟环唑、唑胺菌酯、氟硅唑、吡唑醚菌酯、四氟醚唑8种杀菌剂可作为防治橡胶树白粉病的备选药剂.     

气相色谱法测定氟环唑的含量

[目的]建立一种气相色谱测定氟环唑含量的分析方法。[方法]采用气相色谱法,使用DB-5毛细管色谱柱和氢火焰离子化检测器,以邻苯二甲酸二环己酯为内标物,对试样中的氟环唑进行分离和测定,内标法定量。[结果]当氟环唑质量浓度在4～140 g/L范围内,方法的线性相关系数为0.9999,氟环唑原药的标准偏差为0.35,变异系数为0.36%,平均回收率为99.6%,氟环唑悬浮剂的标准偏差为0.21,变异系数为1.65%,平均回收率为99.8%。[结论]方法简单、快速、准确,适用于氟环唑的定量分析。     

氟环唑的合成综述

氟环唑(Epoxiconazole)商品名欧搏,是一种新型,广谱,持效期长的三唑类杀菌剂,近年来国外对其应用研究较多,德国巴斯夫公司开发了两个以氟环唑为主要成分的混剂。(氟环唑)已在德国     

氟环唑的挥发特性研究

研究了氟环唑在空气中、水中及土壤表面的挥发特性,为该药的环境风险提供数据支持。采用室内模拟的试验方法研究氟环唑的挥发性,通过高效液相色谱法测定氟环唑的挥发率,评价氟环唑的挥发性。结果表明:在(25±1)℃,气体流速为500 mL/min的条件下,氟环唑在空气中、水中及土壤表面的挥发率分别为0.11%、0.07%、0.10%。挥发试验的平均回收率分别为96.2%、99.5%、92.5%,满足回收率试验不低于70%的试验有效性要求。氟环唑在空气中、水中及其土壤表面的挥发率均0.11%,表明氟环唑在空气中、水中及土壤表面均为难挥发,挥发等级均为Ⅳ级。     

苯醚甲环唑合成工艺研究进展

苯醚甲环唑(Difenoconazole)是一种新型、广谱、持效期长的三唑类杀菌剂。本文简述了氟环唑的几种合成方法。     

氟环唑杀菌剂的市场概况

综述了氟环唑的市场概况,评述了开发氟环唑产品市场存在的机遇与挑战,介绍了氟环唑的主要产品及其国内外的登记情况.     

氟环唑生产废水的测定及评价

文章就氟环唑生产废水综合处理工艺流程讨论了其废水中污染物的测定方法,为工业园区氟环唑生产废水的监测方法提供了技术支持,同时通过结果分析与评价,为氟环唑生产废水达标排放提供理论依据。     

氟硅唑·丙环唑混合药剂高效液相色谱分析

[目的]建立一种高效液相色谱法测定氟硅唑·丙环唑混合药剂有效成分含量的定量分析方法。[方法]采用高效液相色谱法,以甲醇和水(体积比85∶15)为流动相,流速为1 m L/min,以220 nm为检测波长,对混合样中氟硅唑和丙环唑进行液相色谱分离测定。[结果]氟硅唑和丙环唑保留时间分别为4.627、5.640 min,线性相关系数分别为0.9999和0.9983,标准偏差分别为0.0873、0.0707,变异系数分别为0.3363%、0.0945%;平均回收率分别为98.80%、97.34%。[结论]该方法操作简便,分离效果好,精密度与准确度高,可同时测定氟硅唑和丙环唑含量。     

氟环唑与氟唑菌酰羟胺及其复配对小麦赤霉病菌的室内毒力及田间防效

为了降低小麦赤霉病菌潜在抗药性的产生,筛选出高效防治药剂,本研究测定氟环唑和氟唑菌酰羟胺及其5种不同配比混剂的室内毒力,并进行了增效组合筛选及田间防效验证试验。结果表明,氟环唑、氟唑菌酰羟胺的EC₅₀分别为0.870 2、0.289 5 mg/L;氟环唑和氟唑菌酰羟胺按照1∶1质量比混配后的EC₅₀为0.270 6 mg/L,协同增效系数为1.605 6,具有增效作用。其按质量比1∶1复配后的组合物防效显著优于其单剂的防效及市场上其他单剂防效,最高可达90.16%。     

加拿大批准先正达苯并烯氟菌唑及数种复配制剂登记

<正>加拿大有害生物管理局(PMRA)近日建议批准先正达苯并烯氟菌唑登记,并批准含有该活性成分的A15457 TO及Aprovia杀菌剂产品,用于防治草坪、观赏植物和数种作物中的真菌病害。此外,PMRA还建议批准数种苯并烯氟菌唑的复配制剂的登记。包括苯并烯氟菌唑和嘧菌酯复配的Mural杀菌剂和Elatus、与丙环唑复配的A18933杀菌剂、与苯醚甲环唑复配的Aprovia Top及     

Olfactory-based behavioral interactions among five species in the southern pine bark beetle group

Olfactory-mediated behavioral interactions were investigated among the five scolytid species comprising the southern pine bark beetle group. Behavioral response, as determined from field trap catch data, showed that each species was attracted in greatest numbers to the pheromonal blend produced by conspecifies. Interspecifically,D. frontalis displayed no cross-attractancy toIps pheromonal blends, but was weakly attracted to the pheromonal blend of femaleD. terebrans. ThreeIps species displayed varying degrees of cross-attraction as well as to theDendroctonus pheromonal blends. More specifically,I. calligraphus was attracted toI. avulsus and, to a very limited extent, also to the maleD. terebrans pheromonal blend.I. avulsus was somewhat more cross-attractive thanI. calligraphus and showed attraction to the pheromonal blends of femaleD. frontalis, male and femaleD. terebrans, maleI. calligraphus, and maleI. grandicollis. I. grandicollis showed the greatest degree of cross-attraction, particularly in response to theDendroctonus pheromonal blends.Research support in part by CSRS grant 86-CRCR-1-2270, NATO grant CRG.0710/86 and Texas Agricultural Experiment Station project MS1525 (while M.T.S. and T.L.P. were with Texas A&M University). The findings, opinions, and recommendations expressed herein are those of the authors and not necessarily those of the U.S. Department of Agriculture.     

Density-Dependent Reduction and Induction of Milkweed Cardenolides by a Sucking Insect Herbivore

The effect of aphid population size on host-plant chemical defense expression and the effect of plant defense on aphid population dynamics were investigated in a milkweed-specialist herbivore system. Density effects of the aposematic oleander aphid, Aphis nerii, on cardenolide expression were measured in two milkweed species, Asclepias curassavica and A. incarnata. These plants vary in constitutive chemical investment with high mean cardenolide concentration in A. curassavica and low to zero in A. incarnata. The second objective was to determine whether cardenolide expression in these two host plants impacts mean A. nerii colony biomass (mg) and density. Cardenolide concentration (microgram/g) of A. curassavica in both aphid-treated leaves and opposite, herbivore-free leaves decreased initially in comparison with aphid-free controls, and then increased significantly with A. nerii density. Thus, A. curassavica responds to aphid herbivory initially with density-dependent phytochemical reduction, followed by induction of cardenolides to concentrations above aphid-free controls. In addition, mean cardenolide concentration of aphid-treated leaves was significantly higher than that of opposite, herbivore-free leaves. Therefore, A. curassavica induction is strongest in herbivore-damage tissue. Conversely, A. incarnata exhibited no such chemical response to aphid herbivory. Furthermore, neither host plant responded chemically to herbivore feeding duration time (days) or to the interaction between herbivore initial density and feeding duration time. There were also no significant differences in mean colony biomass or population density of A. nerii reared on high cardenolide (A. curassavica) and low cardenolide (A. incarnata) hosts.     

Ancestral semiochemical attraction persists for adjoining populations of siblingIps bark beetles (Coleoptera: Scolytidae)

Three species ofIps pine bark beetles in Hopping's group IX (S.L. Wood'sgrandicollis group),Ips confusus, I. lecontei, andI. paraconfusus, are parapatrically distributed in the American Southwest. They share post-Pleistocene altitudinal ecotones with their host pines. Adjacent to these areas of host overlap, we tested the hypothesis that aggregation pheromones produced by male beetles and/or host volatiles are sufficient to elicit the speciesspecific colonization behaviors typical of these threeIps species in nature. A more distantly related species,I. pini (Hopping's group IV, S.L. Wood'spini group) was used for outgroup comparison. Under the influence of pheromone, males ofI. confusus andI. paraconfusus do not discern among unin-fested log bolts of host and nonhost pine prior to bark contact. Males responding to pheromones emanating from infested bolts are similarly undiscriminating. Females ofI. confusus andI. lecontei olfactorily discern the combination of conspecific males in host pine from other possible beetlepine combinations; females ofI. paraconfusus do not. FemaleI. pini discerned conspecific pheromone from that ofI. lecontei. The bark beetle predator,Enoclerus lecontei, is attracted by, but does not discriminate among, the male-produced volatiles of these Group IXIps species. These results support a hypothesis that divergence in pheromonal responses by these group IXIps species has evolved following their speciation, having been manifested first in the female sex. Evolutionarily, the derived pheromonal messages have preceded their behavioral discrimination by these beetles. Additional speciesspecific cues may operate between the sexes in the field that may preclude heterospecific pairings.     

Interspecific response to sex pheromones,and calling behavior of severalAttagenus species (Coleoptera: Dermestidae)

Females of severalAttagenus species demonstrated calling behaviors similar to those previously reported forA. elongatulus. Attagenus rufipennis females did not call until they were 12–14 days old. OtherAttagenus species called at approx. 4 days of age. All species exhibited diurnal periods of calling activity. Interspecific pheromone responses were tested, withA. megatoma megatoma, A. megatoma canadensis, A. megatoma japonicus, andA. schaefferi spurcus showing equal cross-responses. Male response to females was demonstrated inA. rufipennis andA. bicolor. Attagenus rufipennis, bicolor, andelongatulus males responded only to female extracts of their own species.Mention of a proprietary product does not constitute an endorsement by the USDA.     

Allelopathic interactions among algae

Five species of green algae isolated from the Cleveland County, Oklahoma, area and a commercially obtained yellow-green alga were tested for allelopathic interactions. Axenic cultures ofPandorina morum Bory were stimulated in three sterile filtrates from nonaxenic cultures ofScenedesmus incrassatulus var.mononae G.M. Smith, with the oldest filtrate showing the least stimulation. By measuring the growth of axenic cultures inoculated into sterile filtrates of old cultures, instances of inhibition and stimulation were recorded in three screening experiments.Cosmarium vexatum West filtrate was inhibitory to the five other species, a characteristic probably important in its role of producing waterblooms in ponds and swamps. The allelopathic effects of filtrates of the five other species onBolrydium becherianum Vischer could be a key to its restriction to terrestrial sites. Instances of heat lability of the active substances were noted. These interactions, both allelopathic and stimulatory, probably play a significant role in the succession of algal blooms in nature.     

国外生物降解聚合物的种类及主要组分

据１９９６～１９９８年国外有关文献的汇集,由美,日,德等国主要研制,生产的生物降解聚合物种类为：１,单一型生物降解聚合物;（１）合成酯（酸）类;（２）淀粉基材料;（３）天然高分子材料;２、复合型生物降解聚合物;（１）不同种类的烃基互聚物;（２）烃酯（酸）／聚酯（３）脂肪族聚酯／芳香族聚酯共聚物;（３）淀粉基复合型,（５）光／生物降解聚合物;３、可生物降解水溶性聚合物。     

Plant-determined variation in the cardenolide content,thin-layer chromatography profiles,and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa

The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 g of cardenolide per 0.1 g dry weight with a mean of 90 g per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 g of cardenolide per 0.1 g dry weight with a mean of 179 g. Total cardenolide per butterfly ranged from 54 to 1279 g with a mean of 319 g. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED₅₀ units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications. About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR _f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR _f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR _f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.Lepidoptera: Danaidae.Apocynales: Asclepiadaceae.This study was supported by U.S. National Science Foundation grants DEB 75-14265 and 78-10658 to Amherst College and BSR-8119382 to the University of Florida with L.P. Brower as Principal Investigator and DEB75-14266, DEB78-15419, and DEB-81-19391 to the University of California at Davis with J.N. Seiber as Principal Investigator.     

Modified dynamic matrix control

DMC (Dynamic Matrix Control) has been used successfully in industry for the last decade. It can deal with constraints and unusual dynamic behavior directly. It also shows a good control performance for the servo problem. Relatively, it can’t reject disturbances systematically. We propose a modified DMC method to control the regulatory process more efficiently. The proposed DMC method makes the control output by subtracting the estimated disturbance from the control output of the original DMC. Here, the disturbance is estimated by a new disturbance estimator. It shows better control performances than the original DMC.     

Soil nutrient depletion by agricultural production in Southern Mali

The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.     

Influence of life history differences of two tachinid parasitoids ofHelicoverpa zea (Boddie) (Lepidoptera: Noctuidae) on their interactions with glandular trichome/methyl ketone-based insect resistance in tomato

The effects of glandular trichome/methyl ketone (2-tridecanone and 2-undecanone) -based insect resistance in the wild tomato,Lycopersicon hirsutum f.glabratum C.H. Mull, accession PI 134417, onArchytas marmoratus (Townsend) andEucelatoria bryani (Sabrosky) (Diptera: Tachinidae), both parasitoids ofHelicoverpa (=Heliothis)zea (Boddie) (Lepidoptera: Noctuidae), were investigated in the laboratory.A. marmoratus deposits larvae (planidia) on the foliage of its host's food plant; planidia attach to passing hosts, penetrate the cuticle, and develop in the host pupae.E. bryani larviposits directly into its host; its larvae develop in the host larva.A. marmoratus planidia are killed by glandular trichomes of PI 134417 and also by trichomes of hybrid lines with no methyl ketones. The methyl ketones are toxic to planidia, but at least part of the effect is due to other factors, possibly physical entanglement. Both species can be affected indirectly by methyl ketones in the diet of the host. 2-Undecanone reduces the percentage ofA. marmoratus larvae that reach pupation. This effect is evidently due to premature death and desiccation of the host pupa caused by 2-undecanone. 2-Tridecanone in host diets had no effect onA. marmoratus. InE. bryani, 2-tridecanone in the diet of the host reduced the number of parasitoids yielded by each parasitized host, although not the overall percentage of hosts parasitized. 2-Undecanone in the diet of the host had no effect onE. bryani.We thank M. Woodall for typing; V.B. Covington, D. Bumgarner, and B. O'Brien for technical assistance; L.A. Jones for assistance with gas chromatography; P.H. Adler for supplyingE. bryani puparia to initiate colony; and Drs. F. Gould, G.C. Rock, and M. Barbercheck for comments.