8种杀菌剂防治葡萄霜霉病田间药效试验

比较了8种杀菌剂对葡萄霜霉病的防治效果。结果表明:烯酰吗啉.甲霜灵30%水分散粒剂600倍液、烯酰吗啉40%悬浮剂600倍液、甲霜.锰锌72%水分散粒剂400倍液、嘧菌酯25%悬浮剂1 500倍液以及氯化十二烷基苄基铵10%水剂1 000倍液对葡萄霜霉病的防治效果良好,显著优于传统药剂三乙膦酸铝80%水分散粒剂500倍液、代森锰锌80%可湿性粉剂800倍液、丙森锌70%可湿性粉剂400倍液。其中,烯酰吗啉.甲霜灵30%水分散粒剂600倍液效果尤佳。     

6种杀菌剂防治黄瓜霜霉病的田间药效评价

[目的]霜霉病是黄瓜的重要病害之一,严重影响其产量.通过试验,进行啶氧菌酯、氰霜唑等杀菌剂对防治黄瓜霜霉病的防控效果对比.[方法]利用喷雾法测定6种药剂对黄瓜霜霉病的防治效果.[结果]6种供试药剂的防效由高到低依次为氟噻唑吡乙酮10％OD、氟菌·霜霉威687.5 g/L SC、吡唑醚菌酯25％EC、氰霜唑100 g/L SC、烯酰吗啉50％WP、啶氧菌酯22.5％SC.[结论]10％氟噻唑吡乙酮可分散油悬浮剂对黄瓜霜霉病有优异的防治效果,末次药后7 d平均防效达84.13％,末次药后14 d平均防效仍为79.21％,且对黄瓜安全无药害,可作为防治黄瓜霜霉病的首选药剂.除22.5％啶氧菌酯水悬浮剂和50％烯酰吗啉可湿性粉剂外的其他几种药剂亦可作为防治黄瓜霜霉病的推荐药剂交替使用.     

The Effect of Film-Forming Polymers on Powdery Mildew of Cucumber

In pot experiments, powdery mildew of cucumber, caused bySphaerotheca fuliginea, was reduced by 64-82% by the film-forming polymer Vapor Gard and by up to 55% by Wilt Pruf. In experiments in polyethylene-covered greenhouses, no harmful effect to the crop was caused by these materials. In one experiment significant disease reductions of 19-67% and 60-96% were obtained by 3% Safe Pack and by the fungicide fenarimol (Rubigan), respectively. The combined treatment of Safe Pack with the fungicide was significantly more effective than either treatment alone, 72-78 days after planting. In another experiment, disease that appeared late in the season was reduced by up to 80, 100, 30 and 96% by Vapor Gard, Folicote, Wilt Pruf and fenarimol, respectively, and was statistically different from the nontreated control in some of the treatments and dates. Most tested substances inhibited germination ofS. fuliginea conidia and growth of its hyphae on leaves of cucumber.     

Effect of Grapevine Training Systems on Development of Powdery Mildew

The effects of two training systems and row spacing on development of powdery mildew caused by Uncinula necator on clusters of 'Chardonnay' and 'Cabernet Sauvignon' grapevines were examined. Disease development was monitored in blocks with two different row spacing (2 and 3 m) in vertical shoot positioned vines (VSP) and in free-positioned, topped vines (FC) with no foliage support wires. The FC vines were hedged to about one meter shoot length. No fungicides were applied and disease powdery mildew level was recorded four to seven days after appearance of the first disease symptoms. During five consecutive years (1994–1998), disease incidence was higher in the VSP system than the FC vines. The difference was high when disease level was low (30% of the clusters in VSP vines infected, compared to 5% in the FC vines) and decreased when disease pressure was high (79% in VSP compared to 46% in FC vines). In the 'Cabernet Sauvignon', in four of the years, disease incidence was higher in the narrow spacing of 2 m between the rows than that in the wider 3 m spacing. Microclimate (temperature, relative humidity and light intensity) was monitored in the cluster zone near the spurs of 'Chardonnay' vines during three weeks in the 1998 season. In VSP vines light intensity was lower then that in FC vines both four and one week before disease symptoms appeared (72% and 18% respectively). The differences in temperature and relative humidity were less than 1°C and 3%, respectively, and most likely did not affect disease development. The results suggested that high light intensity is the primary factor, which limits powdery mildew growth development on field-grown grapevines in the Golan region of Israel. The use of the FC system might be useful in reducing the need of fungicides.     

Association of Increase in Some Biochemical Components with Flax Resistance to Powdery Mildew

An outdoor pot experiment was conducted in 2014/2015 growing season at Giza Agricultural Research Station to evaluate powdery mildew (PM) severity on 18 flax lines. The tested lines were divided into two distinct groups. The first group included 12 highly resistant lines (HRLs). Disease severity on these lines ranged from 1 to 10%. The second group included 6 highly susceptible lines (HSLs) where disease severity ranged from 90–100%. Levels and activities of phenols, alkaloids, proteins, proline, polyphenol oxidase and peroxidase significantly increased in the infected leaves of the HRLs, compared with the HSLs. Of these components, phenols and peroxidase showed the highest increases in the HRLs (102.34 and 199.33%, respectively). These results indicate that the tested biochemical components have roles to play in flax defense against PM through a variety of mechanisms. The results also suggest that phenols or peroxidase in infected leaves could be used in breeding programs to select resistant lines at early stage of PM development.     

Effect of Microclimate on Leveillula taurica Powdery Mildew of Sweet Pepper

ABSTRACT Sweet pepper-Leveillula taurica microclimate relations were studied under controlled conditions and in commercial greenhouses. Conidial germination occurred at 10 to 37 degrees C and was optimal at 20 degrees C. Conidial viability declined as temperatures increased to 40 degrees C for 6 h. Leaf colonization was optimal at 15 to 25 degrees C. Severe leaf infections occurred at 15 to 20 degrees C and conidiation was suppressed at 20 to 25 degrees C. Highest germination rates were observed at 75 to 85% relative humidity (RH). Severity of leaf coverage by symptoms was high for plants which were subjected to longer periods of temperatures between 10 to 15 degrees C and daytime RH between 85 to 95%, and positively correlated with nighttime RH. Disease severity was negatively correlated with lengthy periods of temperatures >25 degrees C, day and night average temperatures, and average daytime RH. Conversely, leaf shedding was relatively high under conditions characterized by long periods of temperatures >20 degrees C and <13 degrees C, and positively correlated with average daytime temperatures and periods of RH <75%. Increasing nighttime temperatures by heating and daytime temperatures by closing the greenhouse side walls reduced disease in two commercial greenhouse experiments. A midseason shift from a cooler greenhouse climate to warm daytime climate halted epidemic development. Flower number and yield were reduced in infected crops.     

几种药剂对马铃薯晚疫病田间防效及经济效益评价

本文评价分析了几种药剂对马铃薯晚疫病的田间防治效果和经济效益,结果表明,氟菌·霜霉威68.75%悬浮剂+丙森锌70%可湿性粉剂+赤·吲乙·芸薹0.136%可湿性粉剂组合处理的防效和经济收益最高,其次依次为氟啶胺50%悬浮剂+氰霜唑10%悬浮剂、霜脲·嘧菌酯60%水分散粒剂、枯草芽孢杆菌1 000亿芽孢/克可湿性粉剂。     

Ultrastructural and Cytochemical Investigations of the Antagonistic Effect of Verticillium lecanii on Cucumber Powdery Mildew

ABSTRACT Chronological events of the intercellular interaction between Verticillium lecanii and cucumber powdery mildew, caused by Sphaerotheca fuliginea, were investigated at different times after inoculation by transmission electron microscopy. V. lecanii hyphae colonized host structures by tight binding, apparently mediated by a thin mucilaginous matrix. As early as 24 h after application of the antagonist, increased vacuolation and disorganization of the cytoplasm of the pathogen hyphae were easily detected. By 36 h after treatment, plasmalemma retraction and local cytoplasm aggregation were typical features of damage. Labeling chitin with the wheat germ agglutinin (WGA)/ovomucoid-gold complex showed that intracellular invasion of S. fuliginea by V. lecanii did not cause extensive host cell wall alterations, except in the area of hyphal penetration. By 48 h after inoculation, further cytoplasm disorganization was observed, as evidenced by the loss of cell turgor and contortion of the cell wall. Such deformation suggests that penetration of the antagonist results from mechanical pressure or localized enzymatic hydrolysis through the action of chitinases, as confirmed by the pattern of labeling obtained with the WGA/ovomucoid-gold complex. By 72 h after contact between the fungi, S. fuliginea cells were markedly collapsed, depleted of their protoplasm due to extensive multiplication of the antagonist, and totally encircled by the antagonist. Based on the current observations, the antagonism of S. fuliginea by V. lecanii appears to involve the following events: (i) attachment of the antagonist to the powdery mildew fungus; (ii) mechanical pressure and production of cell-wall degrading enzymes such as chitinases; (iii) penetration and active growth of the antagonist inside the pathogen hyphae; and (iv) digestion of host tissues and release of the antagonist from dead cells of S. fuliginea. The interaction between V. lecanii and S. fuliginea also affected the morphological and structural features of the haustorial bodies, as shown by increased vacuolation, distortion, and necrotization of the haustorial lobes. These observations provide the first experimental evidence that V. lecanii, primarily known as an entomopathogenic fungus, also has the potential to colonize mycelial structures of S. fuliginea. V. lecanii, therefore, may become a valuable alternative to current management of cucumber powdery mildew in greenhouses.     

Occurrence of New Powdery Mildew on Greenhouse Tomato Cultivars

During a year-round survey on the occurrence of powdery mildew on greenhouse-cultivated tomato plants, the disease was most severe in June and July. All tomato plants (45 commercial cultivars and 11 breeding lines) tested were infected with the pathogen but had different degrees of susceptibility. The pathogen was epiphytic and produced white, round pustules mainly on leaves of tomato plants. The pathogen produced conidia singly on conidiophores and forked appressoria on inoculated tomato leaves and seemed to be an Oidium sp. of Erysiphe polygoni type. Received 18 December 2000/ Accepted in revised form 22 July 2001     

哈茨木霉T-H-30菌株对黄瓜白粉病的防治效果及其促生作用

用哈茨木霉菌株T-H-30在黄瓜上进行促生作用及生物防治效果研究。结果表明,菌株T-H-30对黄瓜有明显的促生作用,能增加黄瓜的叶片数及藤蔓的长度,从而有效提高黄瓜的产量;菌株T-H-30对黄瓜白粉病具有良好的生物防治效果,可有效控制黄瓜白粉病在大田的发展,相对防效达69.9%～78.8%,且对供试植株安全。     

植物白粉病的化学防治进展

对植物白粉病的化学防治历史和发展进行了综述 ,同时介绍了一些重要的药剂及其作用机制 ,并讨论了白粉病化学防治中存在的问题。     

Integrated Control of Powdery Mildew on Field-grown Mango Trees by Foliar Sprays of Mono-potassium Phosphate Fertilizer, Sterol Inhibitor Fungicides and the Strobilurin Kresoxym-methyl

Foliar sprays of solutions of di-potassium hydrogen orthophosphate, K2HPO4 (DKP) and potassium di-hydrogen orthophosphate, KH2PO4 (MKP), commercial systemic fungicides, and an alternating treatment with phosphate fertilizer and systemic fungicides inhibited development of the powdery mildew fungus, Oidium mangiferae, on flowers and bloom clusters of field-grown mango trees. The effectiveness of the alternation treatments with an appropriate systemic fungicide and 1% solution of mono-potassium phosphate (MKP) in controlling powdery mildew on bloom clusters was similar to that of the commercial treatment with the systemic fungicides. However, application of the systemic fungicides alone, on the same dates on which they were applied in the alternation treatment, without application of the phosphate treatment was significantly less effective in controlling the disease than either the phosphate or the alternation treatment. This indicates that the use of phosphate fertilizer has a significant role in disease control and that it can reduce the number of fungicide treatments necessary against powdery mildew by up to 50%. These results were confirmed in large-scale demonstration trials conducted in commercial orchards in 1994 and 1995. Our 1997 findings also revealed that tank-mix treatments of 1% MKP solution with half the recommended quantity of sterol inhibitor fungicide applied at 14-day intervals provided a protection against powdery mildew comparable with or superior to that given by the standard fungicides-based treatment applied at 7-day intervals. Tank-mix treatments of MKP (1%) with sterol inhibitor at the recommended rate or with the new strobilurin Kresoxym-methyl (BAS 490F, strobi), or the BAS 490F alone, were the most effective, and provided >95% protection against O. mangiferae, compared with the control. Phosphate solutions were found not to be phytotoxic to plant tissue. These treatments affected the yield of mango trees: a significantly lower yield was observed on control untreated trees, probably because of powdery mildew infection on flowers. The inhibitory effectiveness of phosphate salts makes them a potential major component of an integrated pest management program.     

凤仙花白粉寄生孢的生物学特性

对凤仙花白粉寄生孢生物学特性研究表明：凤仙花白粉寄生孢生长温度为10～30℃，pH值为5～10；最适生长及产孢温度为20℃，pH值为7。有利于菌落生长的碳、氮源分别为葡萄糖、乳糖和蛋白胨；乳糖和牛肉膏最适于其产孢。光照对菌落生长及孢子产生有明显促进作用。以乳糖作为碳源，牛肉膏作为氮源的察氏培养基有利于孢子的产生。     

切花月季白粉病发病规律观察

地处秦岭山以南,伏牛山以北的十堰市,群山环抱,地理复杂·东经109°15′~111°45′、北纬31°31′~33°20,′横跨3个纬度线,南北兼有的气候带·盛夏绝对最高气温可达39℃,凌冬最低气温可下降到-12℃,海拔最高3 115 m(神农顶),最低92 m(丹江口市区),年降雨量800~1 500mm,无霜期180 d有余。在这一地带虽有山花烂漫,但切花生产仍属空白·随着改革开放的深入,人民生活水平的提高,切花需求量的增加,单靠南方的鲜花,不单增加了运输成本,鲜花也失去了鲜的韵味(鲜花从剪切到消费者手中最少要3 d时间),1997年十堰试种切花,但引进的几个切花月季品种,…     

几种杀菌剂对小麦条锈病田间防治效果研究

小麦条锈病(Puccinia striiformis West.f.sp.tritici Eriks et Henn)是小麦生产上的重要病害,该病在赫章县发生面积大,流行速度快,常给小麦生产造成重大损失。目前,除了选育抗病品种、开展小麦秋播拌种、处理发病中心外,化学防治仍然是减轻小麦条锈病发生程度的有效措施。本试验引进几种杀菌剂进行药效对比试验,结果表明戊唑·百菌清75%可湿性粉剂、三唑酮15%可湿性粉剂对小麦条锈病防治效果达80%以上,增产幅度40%以上,生产中可以推广应用。