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杨树溃疡病的发生规律和防治 总被引:2,自引:0,他引:2
近年来退耕还林、绿色长廊等工程项目的实施,肥东县杨树面积已达10余万亩,大面积杨树纯林造成杨树溃疡病在肥东县发病率已达到30%以上,以当年定植的幼树受害最重,生长量损失在30%左右。 相似文献
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杨树草履蚧的综合防治 总被引:3,自引:0,他引:3
杨树,是蚌埠市的主要树种,现全市杨树已达85万亩.杨树草履蚧危害较重,2001年全市发生面积1.2万亩,造成枯死杨树3 000株;2002年春,全市发生1.5万亩,导致5~10年生杨树20万株成片突然枯死,造成木材生长量减少达5 000m3,直接经济损失达300万元.如果该虫一旦蔓延传播开来,短短3~5年将造成全市杨树毁灭性的危害.为此,经过3年努力,已摸索出了一套实用有效的综合防治技术,现综述如下. 相似文献
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山西杨树蛀干害虫成灾主要原因及防灾基本对策郭美云(山西省林业科学研究所)近十几年来,以光肩星天牛为主的杨树蛀干害虫在我省蔓延为害,在许多地方已泛滥成灾。据1993年统计,全省成灾面积达50余万亩,被害株率一般60%以上,最高达100%,虫口密度最高达... 相似文献
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翻耕灭蛹防治杨小舟蛾的效果评价 总被引:2,自引:1,他引:2
<正> 杨树是石首市主要速生用材树种之一。1981年以来,在全市17个乡镇、办事处广泛栽植,造林面积近十万亩。近几年随着杨树面积的扩大,害虫的发生日趋严重。1987-1988年全市杨树,有一半以上被杨小舟蛾危害,严重的地方,受害株率达85-90%,单株虫口密度高达2317头,叶片全被吃光。严重的影响了杨树正常生长,给林业生产造成了巨大的经济损失。为了保证林业的稳步发展和林木的正常生长。笔者经过几年的观察,试验研究,在掌握杨小舟蛾生物学特性及危害规律的基础上,使用了人工物理防治,即“翻耕灭蛹防治杨小舟蛾”的方法,收到了明显的效果。 相似文献
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梨齿盾蚧Quadraspidiotus perniciosus(Comstok)是国际检疫对象,我国分布于二十几个省市,过去主要危害果树和花卉。随着欧美杨的大量引进,在杨树上的发生面积逐年扩大,危害程度越来越重,潍坊市杨树受害面积达23万余亩,虫株率达79%,平均虫口为323.7头/10cm~2,杨树2万多株。为此我们于1985年~1988年间,在潍坊、泰安的部分县、市对该虫进行了调查研究和防治试验,现报告如下。 相似文献
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用截头法栽植杨树防治溃疡病机理的研究 总被引:2,自引:0,他引:2
由Dothiorella gregaria Sacc.引起的杨树大斑型溃疡病在辽宁、河北和山西等省为害严重,它是影响造林成活率的主要因素之一。国内外许多学者一致肯定树皮含水量的增加能提高对皮部溃疡病的抗性。钟兆康曾认为,由Dothichiza populea Sacc.etBr.所致的杨树溃疡病的发生还与树干失水有关。我们的试验表明,由D.gregaria引起的大斑型溃疡病受木质部相对含水量的影响最大。因此使用截头法栽植杨树,对防治溃疡病、提高幼树成活率和生长量均有显著作用。这一结论已为大面积推广应用所证实。本文着重对这种栽植技术的防病机理是否与提高了树体含水量有关作进一步探讨。 相似文献
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Xiang Cunti Sun Haifeng Li GuishengNortheast Forestry UniversityWu Xingyin Li Zhuo DangWenqiang Zhang Jinghua Zou XipinAcheng Forest Bureau of Heilongjiang Province 《林业研究》1991,2(1):48-55
The bacterial swollen stem canker of poplar is prevalent in planted poplars ofnortheast China.Serious damage occurs in the form of necrosis,putridity,cankers,swollen stemsand discolored wood of trunks and branches of young and mature trees.Tests of allergic reaction,pathogenicity,culture characteristic,Gram stain and anaerobic culture revealed that the pathogen isErwinia sp.Its occurrence depends mainly on the predisposing factors of the disease among whichthe susceptibility of poplars is the most important one.The disease becomes widespread in associa-tion with low-lying and high-humidity terrain,frost injury,node wounds,insect damage,and prun-ing and other mechanical wounds.Harmful factors promote the disease. 相似文献
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白银地区优良林草品种选择与林草复合经营技术试验 总被引:1,自引:0,他引:1
对优良林草品种的选择和林草复合经营技术试验结果表明 :引进的速生杨、速生柳各无性系间的扦插繁育和植苗造林成活率均不存在显著性差异 ;速生杨、柳苗期生长量与对照 (新疆杨、旱柳 )相比差异显著 ,90 %以上可当年育成一级壮苗 ,造林后速生杨、柳幼树初期生长量显著快于对照 ;引进的美国紫花苜蓿品种在林草复合经营中的品质和产量与对照相比有明显优势 ;林草间作的经济效益远远高于普通农作物种植 ,林草复合系统中草的收益完全可以保证林木成材前幼林的抚育费用 ,并可实现盈利 90 0~ 15 0 0元 /hm2 。 相似文献
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T. R. Gordon S. C. Kirkpatrick B. J. Aegerter A. J. Fisher A. J. Storer D. L. Wood 《Forest Pathology》2011,41(3):227-232
Pitch canker, caused by Gibberella circinata, was discovered in California in 1986. Although initially quite damaging to Monterey pines (Pinus radiata), the severity of pitch canker has moderated in areas where the disease was first observed and some trees appear to have recovered completely. The absence of symptoms on trees that were once severely affected implies they have become more resistant to the disease. Experimental work has shown that P. radiata can manifest systemic induced resistance (SIR) in response to infection by the pitch canker pathogen and observations of disease remission may indicate that SIR is operative under natural conditions as well. As a test of this hypothesis, the susceptibility of trees in remission was assessed by inoculating them with G. circinata and recording the extent of lesion development. In addition, randomly selected trees in areas that differed in residence time of pitch canker were inoculated to determine if trees with a longer period of exposure to the pathogen were more resistant to the disease. The results of these tests showed that 89% of trees observed to be in remission sustained very limited lesion development, consistent with resistance to pitch canker. Furthermore, trees in areas where pitch canker was well established tended to be more resistant than trees in areas where the disease was of more recent occurrence. In sum, these findings support the view that SIR occurs in P. radiata and is contributing to a moderation of the impact of pitch canker under natural conditions. 相似文献