海南省胡椒主要病害现状初步调查

为明确海南省胡椒主要病害种类及发生情况,对海南省琼海、文昌、万宁、海口、定安、临高、儋州、澄迈、屯昌等9个市(县)进行了调查,结果表明:(1)目前危害海南胡椒生产的主要病害有9种,其中真菌病害5种,为胡椒瘟病、胡椒枯萎病、胡椒根腐病、胡椒炭疽病和胡椒煤烟病;细菌病害1种,为胡椒细菌性叶斑病;病毒病害1种,为胡椒花叶病;其他病害2种,为胡椒根结线虫病和胡椒藻斑病。(2)分布广且危害严重的有胡椒瘟病、胡椒花叶病、胡椒根结线虫病和胡椒枯萎病。     

中国苹果病害发生与分布现状调查

本研究于2010-2012年在我国18个省(市、自治区)的1 100个苹果园采用隔行踏查法进行了实地调查。调查内容包括果园面积、品种名称、树龄结构以及各种病害发生情况。调查结果表明,3年间在我国苹果主产区共发现病害50种,其中包括新发现的2种病害:丝核菌叶枯病和炭疽菌叶枯病。通过分析确定了各种病害的严重度,明确了腐烂病、轮纹病、褐斑病和斑点落叶病4种主要病害及苹果锈病等8种中度发生病害的发生程度及区域分布,为各苹果主产省开展病害防控提供了理论依据。     

甘肃玉米主要病害发生动态调查

为了掌握甘肃玉米病害的发生动态,明确主要病害的流行趋势,采用随机抽查法调查了甘肃庆阳、平凉、天水、陇南、定西、武威和张掖7个市/地区的玉米病害类群。结果表明,普通锈病、红叶病和穗腐病普遍发生并较严重,在7个市/地区的平均病株率分别为81.6%、80.6%和77.3%;大斑病、纹枯病、交链孢叶斑病、茎腐病、小斑病、瘤黑粉病和鞘腐病局部发生较重,在7个市/地区平均病株率分别为83.3%、44.9%、29.1%、27.5%、25.6%、14.4%和8.3%,矮花叶病和丝黑穗病普遍发生但发病较轻,在7个市/地区病株率分别为3.1%和1.1%,但矮花叶病在旱作区平凉市依然严重,丝黑穗病在武威市和张掖市的玉米制种田发病率依然较高。调查表明,甘肃玉米叶部病害、穗腐病和茎腐病有加重趋势,今后应该加强多病害抗性品种选育和防治用化学药剂的筛选研究。     

烟草苗床的土壤消毒

全国烟草侵染性病害调查研究结果表明,我国烟草的苗期病害已查明有17种,就其为害程度可作下述划分: 主要病害;炭疽病、猝倒病和立枯病; 次要病害:根黑腐病和普通花叶病毒病; 少见病害:菌核病和菟丝子病; 偶发病害;白粉病、灰霉病、角班病、剑叶病、镰刀菌根腐病、黑胫病、蛙眼病、黑霉斑病、根结线虫病和黄瓜花叶病毒病。 就其病原越冬和初染源形成可划分: 病原随病株残体在土壤中越冬者;炭疽病、立枯病、普通花叶病、灰霉病、角斑病、蛙眼病和黑胫病7种;     

吐鲁番地区哈密瓜病虫害发生及防治技术

<正>哈密瓜病虫害严重影响其产量和品质,现将主要病虫害的发生与防治技术简介如下。1主要病虫害1.1主要病害在吐鲁番地区哈密瓜常见的病害有猝倒病、枯萎病、蔓枯病、疫病、炭腐病、白粉病、霜霉病、炭疽病、叶枯病、细菌性叶斑病、病毒病、寄生性植物瓜列当及菟丝子、寄生线虫和生理性病害(如日灼病、裂瓜和缺素病)等。1.2主要虫害在吐鲁番地区哈密瓜上主要虫害有瓜蚜、瓜叶螨、温室白粉虱、守瓜、潜叶蝇及地下害虫蟋     

玉米病害发生现状与推广品种抗性对未来病害发展的影响

 随着全球气候变化、耕作方式改变和新品种推广,我国玉米病害的发生也有所改变。在春玉米区,丝黑穗病仍然持续严重为害,大斑病呈加重趋势;在夏玉米区,局部地区小斑病发生较重,而矮花叶病普遍发生较轻;以往的次要病害已成为重要病害:如,南方锈病在夏玉米区南部严重发生,瘤黑粉病成为生产中的突出问题,土传病害日益加重,细菌性病害发生渐多。对玉米主要推广品种、近年国家和主产省份审定品种的抗病性分析表明,在北方春玉米区,由于品种抗性水平降低、个别感病品种的推广及病原菌致病力变异,大斑病在近年仍将呈现较重发生趋势;丝黑穗病的发生则由于推广抗病品种和种子包衣技术而有所减轻,但局部地区仍会严重发生;由于缺乏抗病品种,灰斑病和弯孢菌叶斑病的发生将主要取决于气候因素。在北方夏玉米区,小斑病暴发的可能性较小,但已有强致病力菌株出现;由于推广品种普遍对茎腐病抗性水平较低并受耕作制度的影响,茎腐病和苗枯病将成为主要病害;多数品种对南方锈病缺乏抗性,南方锈病发生面积将继续扩大,发病程度也将增加。     

柬埔寨木薯主要病害及从中国引进品种花叶病发生情况

2016—2018年,笔者对柬埔寨木薯主栽区病害进行了调查。普查结果表明,花叶病、褐斑病、细菌性萎蔫病、丛枝病、炭疽病和根腐病是当地木薯种植中的主要病害。花叶病是为害最为严重的病害,而褐斑病发生面积最大。调查了引种至当地的中国木薯主栽品种发病情况,发现华南系列、桂热系列等品种均受花叶病严重为害。分子鉴定结果表明,引起当地花叶病的病原为斯里兰卡木薯花叶病毒株系。     

重庆市草坪草病害种类调查及病原鉴定初报

为了明确重庆草坪草主要病害及其病原菌的种类,作者调查了重庆草坪草病害种类,并分离鉴定了病原。结果表明：重庆草坪草常见病害有锈病、结缕草炭疽病、褐斑病、镰刀枯萎病、结缕草弯孢霉叶枯病和结缕草根结线虫等病害,分别由柄锈菌（Puccinia spp.）、尾状炭疽菌（Colletotrichum caudatum）、立枯丝核菌（Rhizoctonia solani）、镰刀菌（Fusarium sp.）、弯孢霉（Curvularia spp.）和根结线虫（Meloidogyne sp.）危害所致。     

剑河县大白菜主要病害发生特点及防治对策

2013—2017年田间调查表明,剑河县大白菜病害主要有病毒病、霜霉病、软腐病、褐腐病、炭疽病、黑斑病、白斑病、干烧心8种。结合8种病害的发生特点及防治水平,提出综合防治方法。     

保定市山药病害种类及为害特点调查初报

2006～2008年,通过调查鉴定,基本摸清了保定市当前山药生产上发生的病害种类及其为害特点,明确了威胁生产的病害有叶斑类4种,地下部真菌病害4种、线虫类2种.重要病害是炭疽病、镰刀茵枯萎病、短体线虫病,具有潜在为害性的病害是镰孢褐腐病、根结线虫病、病毒病.     

Rice Diseases in Nigeria

Abstract

The two major fungal diseases of rice in Nigeria are rice blast (Pyricularia oryzae Cav.) and brown spot (Cochliobolus miyabeanus (Ito and Kuribayashi) Dreschler ex Dastur). The loss in grain yield attributable to these diseases ranges from 11.5–39.6% and 12–43% respectively, Mancozeb, blasticidin-S, fentin hydroxide, benomyl and edifenphos as foliar sprays effectively control rice blast in the laboratory and field. Brown spot is controlled by spraying with thiram, mancozeb or blasticidin-S. A more useful approach to the control of these diseases being adopted in Nigeria is the search for horizontally resistant varieties. Other fungal diseases of rice in Nigeria are the green smut (Ustilaginoidea virens (Cooke) Tak.), basal sheath rot (Rhizoctonia solani Kühn), sheath blight (Corticium sasakii (Shirai), Matsumoto.), leaf scald (Rhynchosporium oryzae Hashioka and Yokogi), narrow brown leaf spot (Cercospora oryzae Miyake) and bakanae disease, a foot rot caused by Fusarium moniliforme Sheldon. Two suspected cases of virus diseases have been reported; grassy stunt disease (transmitted by Nilaparvata lugens Stal.), and orange leaf disease (transmitted by Inazuma dorsalis (Motschulsky). No bacterial disease of rice has been found in Nigeria.     

Control of Plant Diseases by Extracts of Inula viscosa

ABSTRACT Leaves of Inula viscosa were collected from the field, dried, and extracted with a mixture of acetone and n-hexane. The oily, water-insoluble pastes obtained after evaporation of the solvents were used for the control of foliar diseases in growth chambers. The pastes, either dissolved in acetone or emulsified in water, effectively controlled downy mildew of cucumber, late blight of potato or tomato, powdery mildew of wheat, and rust of sunflower. Mean effective dose (concentration) required for 90% inhibition of disease values for acetone solutions and water emulsions ranged from 0.68 to 1.02% and 0.65 to 1.00% (wt/vol), respectively. Dry matter content in fresh leaves, paste-extract yield in dry leaves, and disease control efficacy of paste extracts were similar in leaves of I. viscosa collected during May to October, suggesting that, for practical use, harvests can be conducted during most of the growing season. The results show that I. viscosa may be used as an herbal source for fungicidal preparations against foliar diseases caused by pathogens belonging to the families Oomycetes, Ascomycetes, and Basidiomycetes.     

Agricultural and Horticultural Fungicides - Past,Present and Future

Abstract

Maize is produced primarily in temperate and warm-temperate zones of the world, but its production is increasing in many tropical regions. Some diseases are common to both of these environmental zones even though their importance may vary greatly. Other diseases are confined to a single zone. The important factors influencing the geographical distribution of maize diseases and some of their vectors are temperature, moisture, cultural practices, and the type and diversity of maize germplasm used. Within tropical zones maize diseases may be segregated into those in humid environments and those favoured by drier, upland climatic conditions. Elevation within the tropics, as this influences temperature, is a factor in distribution of maize diseases.

Late wilt, banded leaf and sheath blight, and Rhizoctonia, Botryodiplodia and grey ear rots occur only in the tropical zone and the warm, temperate areas, while the Sclerospora-incited downy mildew diseases, southern rust, Pythium and bacterial stalk rots, Curvularia leaf spot, and ear rot caused by Diplodia macrospora are much more prevalent there, occurring only occasionally beyond latitudes 34°N and 34°S. Conversely, bacterial wilt, eye spot, and yellow leaf blight have been found to occur only in the temperate zones. Ergot has been found only in a few locations at high elevation (250–270 m) in Central Mexico. Northern leaf blight, common rust, and stalk and ear rots caused by Diplodia maydis and Gibberella zeae prevail in the temperate zones and at high elevations and in winter seasons within tropical latitudes.     

毛叶枣病害调查及炭疽病的研究进展

本文对云南省毛叶枣的炭疽病、焦腐病、白粉病、疫病、黑斑病等真菌性病害和缺硼、缺镁及缺铁的发生情况作了介绍，并简单地概述了炭疽病的研究进展。     

A survey of rice diseases in Bangladesh

Abstract

A survey conducted during 1979–81 in Bangladesh revealed 20 rice diseases, including two viral, two bacterial, 13 fungal, two nematode and one micronutrient deficiency problem. Of these diseases. 16 appeared as major during the period under report. The number of diseases were 17, 16 and 16 during the Boro. Aus and transplant Aman seasons, respectively, with 12 common in all three seasons. Thirteen diseases including bacterial blight, bacterial leaf streak, sheath blight, sheath rot, blast, brown spot, grain spot, stem rot and leaf scald were classified as major; and tungro, bakanae, cercospora leaf spot and zinc‐deficiency were classified as either major or minor, and were common to all regions. Diseases not common in all regions were stack burn, root knot, and ufra classified as major or minor, and false smut, seedling blight. Yellow dwarf and damping off which were always classified as minor. Diseases which were typical for Boro. Aus and transplant Aman seasons were seedling blight and damping off. Yellow dwarf, and false smut respectively. Aus the most humid and warmest season, and the coastal humid areas experienced more major diseases. Seasonal and regional differences in the disease incidence appeared related to agro‐climatic variations.     

Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi

The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1).     

苯并-1,2,3-噻二唑羧酸酯的合成及生物活性

为了寻找更多具有高诱导抗病活性的新化合物,基于对植物抗病激活剂S-甲基苯并 噻二唑-7-羧酸酯(BTH)的结构修饰,设计合成了5个新的含有柔性链及卤原子的苯并噻二唑-7-羧酸酯衍生物,其结构均经过核磁共振氢谱、质谱或元素分析及红外光谱确证。生物活性筛选结果显示,在500 mg/L质量浓度下,化合物 5e及5c对供试的细菌性病害和真菌性病害具有较好的防治效果,其中5e 对瓜类白粉病、瓜类炭疽病和水稻白叶枯病的防治效果均高于90%。     

A broad diversity survey of Rhizoctonia species from the Brazilian Amazon reveals the prevalence of R. solani AG-1 IA on signal grass and the new record of AG-1 IF on cowpea and soybeans

Leaf blight, sheath blight, and web blight are major diseases caused by Rhizoctonia species on both Fabaceae and Poaceae plant hosts in the Brazilian Amazon agroecosystem. To determine the diversity of Rhizoctonia species associated with foliar diseases on fabaceous (cowpea and soybean) and poaceous (rice and signal grass [Urochloa brizantha]) hosts, a broad survey was conducted in Pará, Rondônia, Roraima, and Mato Grosso, in the Amazon, from 2012 to 2013. We extended our survey to Cerrado areas of Mato Grosso, and the lowlands of Paraíba Valley, in São Paulo, where these Rhizoctonia foliar diseases have not been reported so far. Our findings revealed that these diseases are caused by a diversity of Rhizoctonia solani AG-1 complex. We detected that R. solani AG-1 IA (sexual phase Thanatephorus cucumeris) was the predominant pathogen associated with signal grass leaf blight and collar rot diseases in the Amazon, especially in Rondônia and northern Mato Grosso. In addition, a subgroup of R. solani (AG-1 IF), not previously reported in Brazil, was associated with leaf blight on cowpea and soybean, in Roraima. Another subgroup (AG-1 ID) was also detected in Roraima. In Mato Grosso Cerrados we did not find any of the major Rhizoctonia foliar pathogens. Instead, R. oryzae (Waitea circinata) was the predominant species associated with a collar rot on U. brizantha. In the lowlands of São Paulo, R. oryzae-sativae (Ceratobasidium oryzae-sativae) was the predominant pathogen detected causing the rice sheath spot disease.