共查询到20条相似文献,搜索用时 109 毫秒
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茄丝核菌(Rhizoctoniasolani)引起的苗木猝倒病是一类世界性的苗期病害。受害林木种类多,松杉类针叶树幼苗,发病率达20%~50%,严重时可致80%幼苗死亡。该类病害早就引起了国内外广大植物病理工作者的重视并先后对Rhizoctonia的... 相似文献
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<正> 青龙山林场自六十年代以来,每年都有大量松杉育苗生产任务,而与此同时,松杉苗猝倒病也相续发生发展,致使许多幼苗死亡,严重时死亡率可达40-60%,经济损失较大。为了摸清本地松杉苗猝倒病的病害类型及发生规律,为防治工作提供科学依据,1979年以来,我们调查了花山、青龙山、八分山等分场,并对该病害进行了观察和药土防治试验。现将结 相似文献
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松杉苗圃化学除草试验初报 总被引:1,自引:0,他引:1
松杉苗圃应用除草醚、氟乐灵等8种除草剂,采用随机对比和正交设计方法共设144个小区,接后芽前施药除草率最高达99.8%,苗期杂草减少75%。全年施药2—3次,除草成本只占人工除草的23.5—35.5%。 相似文献
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对腾冲红花油茶苗期病害进行了3年的调查,确定茶饼病、茶立秙病、茶炭疽病、白绢病4种为苗期主要病害.对其病原、植株受害状况、传播途径、发病期等进行了论述,并提出了相应的农业、化学防治措施,认为在茶苗生严中应积极预防、及时防治,病害未发生时以农业预防和化学防治措施为主,病害发生后,应多种农药轮流施用或混合施用,以有效防止腾冲红花油茶苗期病害发生. 相似文献
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正西瓜的整个培育过程中,常出现多种病害,严重影响西瓜的正常生长和产量的提高。其中最为常见的有猝倒病、蔓枯病、疫病、炭疽病四大病害。猝倒病此病是西瓜苗期的主要病害。苗期根颈部呈水浸状病斑,而后病部变褐,幼苗近地面处明显缢缩而倒伏。土壤温度低、温度大时有利菌的生长与繁殖,所以 相似文献
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介绍昭通市林木种苗工作的基本情况,分析全市林木种苗工作发展中存在的主要问题,提出今后一段时期内,昭通市林木种苗管理工作的解决思路。 相似文献
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ZHU Xiaolong Research Institute of Forestry Policy Information Chinese Academy of Forestry Beijing P. R. China 《中国林业科技(英文版)》2007,6(3):66-71
Effects of three gaps which are large (118 m^2), medium (86 m^2) and small (20 m^2), respectively, and under canopy of Tsuga longibracteata forest on the seedling establishment of T. longibracteata were studied through seed burial experiments from December 2003 to January 2005 in Tianbaoyan National Nature Reserve of Fujian, China. The results showed that the area of gap had an evident effect on the seedling establishment of T. longibracteata. The seedling emergence rates of T. longibracteata in plots of large gap, medium gap, small gap and under canopy were 10%, 10%, 4% and 6%, representing an increasing trend along with the gap size increasing without a significant difference. Rain eroding and insects feeding were two main factors leading to seedling death. The larger the gap size was, the more seedlings were killed by rain erosion and the fewer seedlings were killed by insects feeding. The emergence time of seedlings was almost same in all plots while their death time was different respectively. The gap size had a significant impact on seedling survival rate. The seedling survival rate was highest in the medium gap plot (27.0%) and next to the highest in large gap plot (7.3%), and seedling in small gap plot and under canopy plot died out after one growing season. Increased light supply in gaps was favorable for the seedlings growth and survival. Increased light supply in the large gap could enhance the growth of seedling leaf and root of T. longibracteata, and the seedling in turn allocated more dry mass to root and leaf, but it has little impact on the growth of stem. This research indicates that T. longibracteata is a pioneer species and its seedling establishment need a medium or large gap (〉50 m^2). 相似文献
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红豆树总生物量、总干物质、根、茎、苗高、地径等18个苗木性状关系矩阵及主分量分析结果表明:主分量分析中,总生物量指标的特征向量值最大,植株总生物量指标是反映苗木质量的相关中心,最能体现苗木的质量水平,植株生物量可以作为红豆树苗木质量评价的主要指标;除了生物量指标以外,特征向量值次之的为苗高和地径2个指标。植株生物量鲜重、苗高、地径3个因子最能反映红豆树苗木质量水平。 相似文献