皱果赤爬白绢病病原的生物学特征与防治

在对野生珍稀食用植物皱果赤艇的引种驯化中发现白绢病是皱果赤艇生长期的主要病害。本文研究了皱果赤艇白绢病的症状、病原及其生物学特征和发生规律，提出了防治措施。     

魔芋白绢病发生危害与综合防治

魔芋白绢病主要发生在接近地面 1～2cm的植株基部。初侵染源为土壤中的菌核和病残体及带病种芋。大田 6月中下旬开始发病 ,8月上旬至 9月上旬高温高湿条件下危害最重 ;随着种植年限增加 ,田间菌量累积 ,病害逐年加重 ;植株受机械损伤有利于病菌侵入。建立种芋基地 ,选用抗病品种 ,实行轮作倒茬、拔除病株、推行荫蔽栽培和增施钾肥等措施可减轻发病 ;化学防治应采取土壤消毒、种芋处理和大田统防统治等措施控制魔芋白绢病发生危害     

桑皱鞘叶甲生物学特性及综合防治

桑皱鞘叶甲是桑树春叶期的重要害虫，在江西修水县2年发生1代，以成虫和中等大小的幼虫在桑园土下15－60cm深处的土室内越冬，越冬成虫于次年4月下旬至5月上旬大量出土并繁殖为害，为害高峰期为4月底到6月中旬。幼虫分布范围为土下10－65cm，其中以30－50cm最多。当年孵化的幼虫至11月中下旬开始越冬，次年3月中下旬继续取食和生长，9月上旬至10月中旬化蛹，9月下旬至11月底羽化并静伏于土室内过冬。在自然条件下各虫态发育历期为：卵期9－10d，幼虫期15－16个月，蛹期16－19d。成虫寿命8－9个月，其中土下蛰伏6－7个月，出土生活2－3个月。可用昆虫病原线虫压低土中幼虫密度及成虫高峰期施用杀虫剂，并辅以人工防治的方法防治该虫。     

鸢尾白绢病发生动态与综合防治研究

运用形态学和分子生物学技术对鸢尾白绢病的病原菌进行了鉴定,并对病原菌的生物学特性、发生动态和综合防治进行了初步探索。鸢尾白绢病的病原菌经鉴定为Athelia rolfsii。其菌丝最适生长温度为30℃,最适p H为5~6。根据调查,上海地区鸢尾白绢病发病期为6—10月,8月发病率最高。在各类型的鸢尾中以西伯利亚鸢尾发病最重,西伯利亚鸢尾发病高峰期平均发病率为25%。室内药效试验结果显示丙环唑、烯唑醇有较好的控害效果。     

菱角白绢病及其防治

菱角白绢病近年在孝感地区已成为危害菱角的主要病害。该病以成熟的菌核在菱塘埂土及病株残体上越冬，翌春气温升至２３～２５℃时，越冬菌核或其萌发的菌丝藉流水等传播到菱塘，侵入菱叶，形成初侵染；７～８月份高温高湿是该病发生迅速、暴发成灾的主要气象条件；菱塘埂杂草丛生、菱角生长茂密、塘水串灌、漫灌和菱塘连作以及菱角被其他病虫危害均利于发病；以农业预防为基础、发病期间喷瑞毒霉、多菌灵进行药物保护和治疗是控制该病发生的有效措施     

茉莉花白绢病发生特点与防治措施

近年茉莉花白绢病在犍为县种植老区呈加重发生趋势,造成茉莉花减产。经过长期观测和调查,介绍茉莉花白绢病的为害特点、发生规律、发病因素等,并采取有效的防治措施。     

草乌白绢病的症状特点及药剂防治试验

经调查鉴定草乌白绢病由齐整小核菌(SclerotiumrolfsiiSacc.)引起;对分离纯化的病菌进行室内毒力测定试验表明,药剂浓度为1400μg/ml以下时,75%百菌清WP和70%甲基硫菌灵WP的抑菌率均为98%以上;田间防治试验结果表明,70%甲基硫菌灵WP500、1000倍液对草乌白绢病的防治效果较好,为76.3%和65.8%。     

苹果白绢病防治药剂的筛选及使用方法

白绢病是苹果苗期和幼树期的重要病害,可导致死树和死苗。为了筛选有效的杀菌剂,提供有效的病害防控技术,通过花盆土壤施药、撒施药土等方法测试了9种杀菌剂和生石灰对白绢病菌的抑制效果。结果表明,95%甲基立枯磷TC和99%噁霉灵TC两种药剂能有效抑制白绢病菌的生长和菌核的形成,抑制率在80%以上;25 g/L咯菌腈FSC和45%抑菌脲SC对白绢病菌的生长和菌核形成也有抑制效果,但其抑制率不足50%。9种杀菌剂都不能杀死菌核中的病菌。生石灰能有效抑制白绢病菌生长扩展,其抑菌范围超过5 cm,但不能抑制病菌形成菌核。将生石灰撒于根围或土表,或混入育苗基质、锯末或土壤中,可预防苹果苗期和幼树期的白绢病。甲基立枯磷和噁霉灵可用于苗木消毒、浇施、地面喷雾或随滴灌使用。     

绿邦‘98防治菜豆白绢病的药效试验

菜豆白绢病（ＳｃｌｅｒｏｔｉｕｍｒｏｌｆｓｉＳａｃ）是海南菜豆生产中的主要病害之一。笔者采用绿邦｀９８（蔬菜型）防治该病,现将试验结果报道如下：一、试验材料与方法１．供试药剂：绿邦′９８ＷＰ８００倍（北京农业大学产）;枯萎立克ＷＰ（３７％多菌灵草酸盐...     

黄菖蒲白绢病发生规律与防治方法

黄菖蒲(Iris pseudacorus Linn.)又名菖蒲鸢尾,是鸢尾科多年生宿根草本植物,原产欧洲及亚洲西部[1],在长江中下游地区的浅水池中能安全越冬。随着湿地生态系统保护工程的开展,黄菖蒲在水湿地、湖畔、池边的栽植逐渐增多,而黄菖蒲的病害问题也越来越突出,其中黄菖蒲白绢病是发生普遍且比较严重的病害之一。我们对长三角地区花卉苗圃中黄菖蒲白绢病的发生情况进行了调查,现将该病调查的结果报道如下。1症状病害主要发生在黄菖蒲近地面的叶基部。发病部位无异味,病部的皮层初呈水渍状,以后逐渐变褐腐烂,并在病部产生白色绢丝状菌丝。菌丝呈辐…     

Molecular diversity and fingerprints of Trichoderma associated with antagonistic potentials against Sclerotium rolfsii Sacc.

Journal of Plant Diseases and Protection - Antagonistic potentials of Trichoderma isolates were evaluated against the phytopathogen Sclerotium rolfsii causing stem rot in groundnut. The in vitro...     

Biological control of southern blight disease of tomato caused by Sclerotium rolfsii with simplified mycelial formulations of Trichoderma koningii

Two simple formulations of an antagonistic strain of Trichoderma koningii were employed against southern blight disease caused by Sclerotium rolfsii in seedling, potted outdoor and field-grown tomatoes (cvs. Ife No. 1 and Ibadan Local). Corn cob germling inoculum and mycelium powder of T. koningii significantly controlled ( P ≤0·05) symptoms of damping off, blight and wilting in both tomato cultivars. The populations of the antagonist increased from an initial 1 × 10⁴ to about 1 × 10⁶ colony-forming units per g of soil in the protected plants. Moreover, sclerotial counts decreased significantly ( P ≤0·05) in these soils and those sclerotia found had been parasitized by T. koningii. Trichoderma -protected plants were more vigorous than those in the other treatment categories. The significance of these results is discussed in relation to the use of Trichoderma in appropriately simplified formulations.     

Properties and inhibition of Sclerotium rolfsii chitin synthetase

A chitin synthetase (CS) preparation was obtained from mycelium of the plant pathogen Sclerotium rolfsii and partially characterised. The CS activity was stimulated by N-acetyl-D-glucosamine and magnesium cations with an optimum temperature of 30°C and an optimum pH of 6.4. The enzyme required proteolytic activation and so apparently existed in a zymogenic form. The fungal CS was strongly inhibited by the nucleoside-peptide antibiotics polyoxin-D and nikkomycin, and weakly inhibited by the terpenoyl benzimidazole, 1-geranyl-2-methylbenzimidazole. It was insensitive to captan and to insecticidal benzoylphenyl ureas. Disrupted chitin formation caused by polyoxin-D showed as swollen hyphae containing numerous depressions. The antibiotic also reduced formation of sclerotia and the few that did form were large, irregular in shape and light coloured.     

魔芋白绢病菌生物学特性及药剂化肥的抑制与影响研究

魔芋白绢病作为魔芋的主要病害之一,对魔芋生产造成较大的为害.我们虽然从生产实践中对其进行了许多研究,但生产实践中各种试验因子受天气和自然条件以及人为因素影响较大,往往给试验造成不确定性.     

Biological Control of Sclerotium rolfsii and Verticillium dahliae by Talaromyces flavus Is Mediated by Different Mechanisms

ABSTRACT Ten wild-type strains and two benomyl-resistant mutants of Talaromyces flavus were examined for their ability to secrete the cell wall-degrading enzymes chitinase, beta-1,3-glucanase, and cellulase, to parasitize sclerotia of Sclerotium rolfsii, to reduce bean stem rot caused by S. rolfsii, and to secrete antifungal substance(s) active against Verticillium dahliae. The benomyl-resistant mutant Ben(R)TF1-R6 overproduced extracellular enzymes and exhibited enhanced antagonistic activity against S. rolfsii and V. dahliae compared to the wild-type strains and other mu tants. Correlation analyses between the extracellular enzymatic activities of different isolates of T. flavus and their ability to antagonize S. rolfsii indicated that mycoparasitism by T. flavus and biological control of S rolfsii were related to the chitinase activity of T. flavus. On the other hand, production of antifungal compounds and glucose-oxidase activity may play a role in antagonism of V. dahliae by retardation of germination and hyphal growth and melanization of newly formed microsclerotia.     

Effect of propiconazole on growth and sterol biosynthesis by Sclerotium rolfsii

Germination of sclerotia ofSclerotium rolfsii on agar nutrient medium was delayed or slightly inhibited by concentrations of propiconazole between 0.4 and 4.0 μg ml^?1, but was strongly inhibited by 8 μg ml^?1 and completely inhibited by 16 μg ml^?1. On the other hand, growth of hyphae from the germinated sclerotia was strongly inhibited by propiconazole at 1 μg ml^?1 or greater. Hyphal growth from agar discs on agar medium was about 8 times less sensitive than hyphal growth from the sclerotia or from hyphal inoculum in liquid media. Propiconazole at 0.25 and 1.0 μg ml^?1 strongly inhibited ergosterol biosynthesis, but this was not associated with large accumulations of C-14 methyl sterols. The ratio of eburicol to ergosterol in hyphae grown in the presence of 0.25 μg ml^?1 propiconazole for 16, 30 or 45 h was 0.11, 0.13 and 0.04, respectively, for the three intervals while for hyphae grown in the presence of 1 μg ml^?1, the ratios were 0.29, 0.36 and 0.30, respectively, for the same intervals. In view of a ratio of 23.5 for¹⁴C-acetate incorporation into the two sterols during the initial 6 h growth period in the presence of propiconazole, it is believed that the lack of large accumulation of C-14 methyl sterols is due to the feedback inhibition by eburicol or to cell lysis when the content of ergosterol becomes too low in the actively growing cells.     

辣椒白绢病的发生影响因子调查分析及综合防治技术探讨

辣椒白绢病(Sclerotium rolfsii Sacc.)是南方辣椒种植区的一种严重的土传病害.近年来,永定县引进种植加工型小辣椒.2008年该病在小辣椒上严重发生.全县发病面积63.3 hm2,占小辣椒种植面积的41.3%,病田平均病株率19.3%(5.4%～41.5%),造成产量损失达35.65万kg.为更好控制该病在本县的发生为害.笔者对该病的发生规律及其综合防治技术进行了初步探索.