广西桉树焦枯病的流行规律研究

桉树焦枯病是广西近年来较严重的桉树病害之一。经常规组织分离鉴定确定广西桉树焦枯病病原菌主要有5种:Cylindrocladium quinqueseptatum,Cy.floridanum,Cy.scoparium,Calonectria sulawesiensis,Ca.hongkongensis。其中Ca.sulawesiensis和Ca.hongkongensis是国内新发现的2种焦枯病菌。在广西,桉树焦枯病4月下旬开始发病,12月初结束,高峰期在7—8月。病害的发展与当地气候条件关系密切,尤其是降雨量、相对湿度和温度直接影响病害的发生程度。该病的发生程度与桉树的树龄、品种、所处地理位置、坡向、坡位有关。一年生以下桉林或桉苗、北坡和山脚洼地的树林发病较重;广西的两大主栽无性系中,广林9号抗病性较强,而DH 32-29相对较感病。     

桉树主要真菌性病害研究进展

桉树（Eucalyptus spp.）是我国南方重要的速生丰产林树种之一,在营林生产过程均会遭受各种病害的危害,其中以真菌性病害为多,主要有茎腐病、灰霉病、焦枯病、紫斑病、叶斑病、枝枯病、溃疡病等,严重影响桉树正常生长.对这几种病害的分布与危害、发病症状、病原、发病规律和综合防治方面进行了综述.     

桉树叶部病害紫斑病和轮斑病——防治病虫害系列科普文章之七

<正>近年,导致桉树林连片枯黄的主要病害为桉树紫斑病和轮斑病。两种病害常混合发生,大部分地区以紫斑病为主,局部以轮斑病为主。病害严重发生时,桉树生长停滞。桉树紫斑病桉树紫斑病是国内外桉树种植区较为常见的叶部病害,可以危害多种桉树。我国在上世纪80年代就有紫斑病危害窿缘桉、细叶桉、斜脉胶桉、赤桉等桉树的报     

国内外桉树焦枯病研究进展

桉树焦枯病是一种世界性土传病害,严重影响桉树的正常生长。本文主要对桉树焦枯病的病原、病害特征、危害状况、桉树抗病性及防治方法等方面进行了概述。     

桉树萌芽林焦枯病预防营林技术及效益分析

指出了广西属亚热带地区,是我国桉树人工林种植的主要栽培区,桉树种植面积达到3000多万亩,桉树具有生长迅速、可多次萌芽更新的生物学特性。大部分种植户对采伐林地进行萌芽更新利用,但焦枯病是广西桉树萌芽林较严重的病害之一。为此,深入探讨了桉树萌芽林焦枯病预防营林技术,并分析了桉树萌芽林焦枯病预防营林技术对桉树种植的经济、生态、社会效益的影响。     

桉树焦枯病综合防治

桉树焦枯病是造成桉树减产的重要病害。总结桉树焦枯病的发病症状与病害流行规律,建议采取选育抗病品种、林业技术防治、物理防治、化学防治、生物防治以及植物检疫等综合防治手段来防治桉树焦枯病。     

桉树的严重病害——焦枯病

近年来,随着桉树速生品种在我区引进、推广,桉树种植面积迅速增加,病虫害的问题越来越突出。据1991年、1992年调查,焦枯病在我区只是零星发生,而1993年桉树的主要种植区青枯病严重发生,焦枯病也很严重,这是历年来所没有过的。桉焦枯病在一、二年生桉幼林普遍发生,尤以钦州市那彭镇、来宾县铁帽山林场、东门林场的二年生桉幼林最为严重。病害严重发生的林地,大片植株中、下部叶子焦枯脱落,有的甚至枯死。一年生桉树下部叶子发病的现象也很普遍,但严重程度不及二年生桉树。桉焦枯病虽然尚未造成大片桉树枯死,但在生长高峰期     

营林措施防治桉树焦枯病试验

2005—2006年,在永安林业股份有限公司大坑林业采育场应用清洁林分+施肥、疏伐+施肥、锄草+施肥、施肥4种营林措施,进行桉树焦枯病防治试验。结果表明:各种营林措施对防治桉树焦枯病均有显著效果且显著促进桉树林分的生长,以清洁林分+施肥最佳,其次是锄草+施肥、疏伐+施肥,单纯施肥效果最弱;清洁林分+施肥虽然成本最高,但桉树生长量的增长也最大,投入产出最高,为1∶4.44,可在桉树焦枯病受害较重的林分中使用。     

桉树焦枯病和青枯病的分离鉴定与防治方法

简要概述了危害我国华南地区桉树产业发展的主要病害——桉树焦枯病和青枯病,介绍了两种病害的部分研究方法,分析了两种病害的防治方法及其研究方向,以期为相关研究提供借鉴。     

12种桉树焦枯病病原菌对10种桉树无性系致病性初步分析

为了明确在中国发现的桉树叶片焦枯病病原菌Calonectria spp.对桉树的致病力大小,并测定不同桉树无性系对Calonectria病原菌抗病性的强弱,本试验采用在中国发现的12种Calonectria属（Ca. cerciana、Ca. chinensis、Ca. hongkongensis、Ca. microconidialis、Ca. papillata、Ca.parakyotensis、Ca. pauciramosa、Ca. pentaseptata、Ca. pseudoreteaudii、Ca. seminaria、Ca. terrestris、Ca. tetraramosa）共29株致病菌对10个桉树无性系（DH32-22、DH32-29、EC152、EC153、EC155、G1、K31、OC14、U6、W5）进行了室内离体叶片致病性测定。结果显示：12种被测试Calonectria病原菌均能在不同程度上使10个桉树无性系离体叶片产生病斑;不同种Calnectria病原菌对同一桉树无性系的致病性差异显著,不同桉树无性系对同种Calonectria致病菌的抗病能力也存在显著差异。     

Nursery diseases of Eucalyptus in Kerala1

Survey of Eucalyptus (E, grandis and E. tereticornis) nurseries in Kerala State indicates that the most prevalent diseases are damping-off, web blight and seedling blight in seedbeds and stem canker, leaf and shoot blights and Phaeoseptoria leaf spot in container plants. Cylindrocladium spp., Rbizoctonia solani and Pythium spp. arc the main serious pathogens. Pythium myriotylum, P. deliense, R. scilani, Cylindrocladium camellias, C. clavatum and Sclerotium rolfsii are recorded for the first time on Eucalyptus.     

Studies on leaf spot and shoot blight of Eucalyptus caused by Cylindrocladium quinqueseptatum

In glasshouse experiments, Cylindrocladium quinqueseptatum, which was associated with outbreaks of leaf spot and shoot blight in a young plantation of Eucalpytus microcorys in north Queensland during the 1982 and 1983 autumns, was pathogenic on seedlings of E. microcorys and caused varying degrees of leaf spot and shoot blight in ten species of Eucalyptus from major taxonomic groupings of the genus, When the outbreaks occurred, the weather was unusually showery with minimum temperatures above 16°C. In vitro studies showed that free water was essential for conidial germination, which occurred between 14–32°C. The optimum for mycelial growth was 28.5°C. In vivo studies showed that leaf penetration. by germinated conidia was via the stomata. Mancozeb was more effective at controlling the disease than benomyl, captan or copper oxychloride. The potential importance of C. quinqueseptatum and options for control in young Eucalyptus plantations are discussed.     

Effect of some nursery practices on incidence and severity of diseases,and growth of Eucalyptus grandis seedlings*

Nursery practices influenced incidence and severity of diseases of Eucalyptus grandis viz. damping-off caused by Pythium sp., Rhizoctonia solani and Cylindrocladium quinqueseptatum, web might by R. solani, seedling blight by C. quinqueseptatum and shoot wilt by Sclerotium rolfsii. Growth of seedlings of E. grandis and microclimatic conditions were also affected by nursery practices. Shading with coconut leaf thatch led to low light intensity (av. 1463 lux) with high soil water potential, low soil and ambient temperatures, and high severity of damping-off and web blight diseases and poor shoot:root ratio of seedlings. Seed beds under coirmat had dispersed light (av. 22 299 lux), apparently high severity of seedling blight and shoot wilt, and good growth (snoot:root ratio) of seedlings. In both the types of shading high soil moisture regime and high seed rate contributed to high disease severity as well as low shoot:root ratio of seedlings.     

Damage to foliage and stems caused by fungal pathogens in young eucalypt plantations in Zambia

Plantations consisting of non-native tree species were established on the Copperbelt of Zambia to supplement timber supply from natural forests and to meet the increasing demand of round wood and fuel wood for the copper mines. In early 2004, a disease characterised by severe leaf defoliation and death of juvenile trees suddenly occurred in plantations of the Copperbelt Forestry Company. This study was undertaken to determine the nature of the disease and extent of damage caused with a view of providing a framework for sustainable management of the plantations. Disease incidence, severity and impact on plantations using the crown damage index were assessed for three consecutive years. Eucalyptus grandis was more affected than E. cloeziana and leaf spot incidence and severity were higher in Kalibu, Kitwe District, than in Kafubu, Kalulushi District. The incidence in Kalibu was 90.4%, causing tree crown damage of 18.6% at the end of the assessment in 2006 compared to 17.5% incidence and 1.02% crown damage recorded in Kafubu. Fungi collected from leaf tissues included species of Aulographina, Cryptosporiopsis, Cylindrocladium and fungi in the Teratosphaeriaceae. Stem pathogens were identified as fungi in the Botryosphaeriaceae and Kirramyces sp. Diseases induced by these pathogens are increasingly becoming major threats to young eucalypts, resulting in poor stem form. Factors favouring disease development are described and these need to be properly managed to minimise the impact of diseases in addition to the need to establish selection and breeding programmes to develop tolerant genotypes to ensure a sustainable future for the forestry industry in Zambia.     

Pseudocercospora kaiseri sp. nov. causing a necrotic leaf spot of Erythrina

A new species, Pseudocercospora kaiseri, causing leaf spot of Erythrina stricta Roxb. from India is described and illustrated.     

Relative susceptibility of Eucalyptus provenances to Cylindrocladium leaf blight in Kerala,India1

Susceptibility of 46 provenances belonging to 16 species of Eucalyptus to Cylindrocladium leaf blight caused by Cylindrocladium quinqueseptatum, C. clavatum and C. ilicicola differed significantly in detached leaf inoculations. Generally, susceptibility of a provenance to the three species of Cylindrocladium showed significant differences; only a few provenances gave either equally resistant or susceptible reactions to all the three species. C. clavatum was the most virulent species, C. ilicicola the least and C. quinqueseptatum intermediate.     

气流对广东侵染性林木病害发生的影响

在2002—2016年对广东省部分重要林木病害进行现场调查,分析气流与林木侵染性病害发生之间的关系.结果表明,在广东省广泛发生的黧蒴(Castanopsis fissa)枝枯病和桉树(Eucalyptus sp.)梢枯病属于气传病害;气流运动为杉木(Cunninghamia lanceolata)细菌性叶枯病、红豆杉(Taxus chinensis)根腐病、相思(Acaciasp.)根腐病和木麻黄(Casuarina equisetifolia)青枯病病原菌开辟了入侵通道;这些病害的防治策略可进行相应调整.气流运动导致广东省部分重要林木病害的发生,建议开展针对气传病害的试验研究来推动今后的防控工作.     

Long term losses caused by foliar diseases on growth and survival of Eucalyptus globulus in Uruguay

Eucalyptus globulus is the most important forest species in Uruguay, with more than 250,000 ha of commercial plantations. Despite its high susceptibility to diseases, production losses caused by foliar diseases have not been properly quantified in this country. This study analyzes the effects of foliar damage on growth and survival using data from a progeny test of E. globulus naturally infected by Teratosphaeria leaf disease and eucalypt rust (Puccinia psidii). The severity of leaf spots and defoliation were quantified 8 months after planting and tree growth and mortality were evaluated 2, 4 and 6 years later. The trial had a high incidence of foliar damage, with a mean leaf spot severity of 28.7% and a mean defoliation of 37%. The greatest impact of foliar damage, both on growth rate and mortality, occurred in the first 2 years after damage was assessed. During this period, leaf spot severity less than 40% and defoliation below 50% did not affect growth, while survival was affected when leaf damage was 70% or greater. By the sixth year both stem growth and survival were affected by severe foliar damage (spotting or defoliation of 80% or more), with a loss of up to 25% in diameter and an accumulated mortality over 70%. It has been established for the first time that under the intensive Uruguayan productive conditions, E. globulus trees can tolerate a relatively high degree of leaf spotting or defoliation but severe foliar damage in the first months can cause considerable production losses, putting at risk the economical viability of this species.