苗圃地苗木病害的防治探讨

指出了苗圃地是以生产合格苗木,进行引种树种苗木训化和稀有树种苗木培植的基地,而苗木的产量、质量及生产成本等不仅仅只限于苗圃地所在地的自然环境因素,要培育出合格优质的苗木,除了要有科学的育苗方法外还要注意苗圃苗木病害的防治,对苗圃地主要病害例举两类,即苗木猝倒病和苗木根腐病,就其防治进行了探讨。     

松杉苗木立枯病的防治

苗木立枯病，又叫苗木猝倒病，是一种世界性病害，各地苗圃均有发生，针叶类（松、杉）苗木发生更甚。     

辽西地区林果苗圃主要病害种类及防控技术

林果苗圃用地由于连茬耕作,导致苗木病害的高几率发生,给种苗生产带来了较大的经济损失。正确分析林果苗圃病害发生的成因,采取有效防控技术可大大降低林果苗木病害的发生与程度。文章就辽西地区林果苗圃普遍发生的苗木白绢病、茎腐病、猝倒病的发生症状和防控技术作以简介,可供广大林农参考。     

苗木生产谨防侵染性

侵染性病害往往会在短期内造成苗木大量死亡,给苗农带来很大损失。常见的苗木幼苗侵染性病害有猝倒病、立枯病、叶斑病、炭疽病等,现介绍几种综合防治措施。     

日本落叶松苗接种菌根真菌的研究

采用厚环乳牛肝、血红铆钉菇、彩色豆马勃等3种外生菌根菌纯培养接种物。对日本落叶松播种苗进行接种试验，测定其对苗木根部病害的生物防治作用。实验表明，3种外生菌根真菌对苗木根部病害及苗木猝倒病均有明显的抑制作用。接种不同菌根真菌的松苗猝倒病发病率比对照组降低30．3％--58．6％，苗高、地径、单株鲜重等生长指标提高5．9％-65．0％，菌根侵染率达61．3％-68．1％。     

六六六防治松、杉苗木猝倒病的初步研究

猝倒病是松、杉苗木的主要病害之一。在苗木出土后二个月左右,往往由于发生猝倒病造成大量死亡,严重影响苗木产量和质量。据不完全统计,一九七三年我县松、杉苗木由于遭受猝倒病危害损失达40%以上,部分社队高达90%以上。因此,防治猝倒病是当前松、杉育苗工作中急待解决的一个技术问题。     

苗木猝倒病的综合防治

苗木猝倒病是我国各省区苗期病害中一种最普遍而严重的病害,除为害杉木属、松属、落叶松属等苗木外,也为害油橄榄、檫木、银杏、桦木、刺槐、木荷、臭椿等多种阔叶树种苗木,苗木因病死亡率平均20％,严重时超过50％。病菌种类和特点苗木猝倒病主要是由丝核菌(Rhizoc-     

针叶树苗木猝倒病发病机理及防治技术

针叶树苗木猝倒病是危害针叶树育苗的主要病害。本文介绍了猝倒病发病的主要症状、发生原因、发病规律,提出了防治猝倒病发生的有效措施。     

苗木生产谨防侵染性病害

侵染性病害往往会在短期内造成苗木大量死亡,给苗农带来很大损失。常见的苗木幼苗侵染性病害有猝倒病、立枯病、叶斑病、炭疽病等,现介绍几种综合防治措施。一、选好圃地。应选水源较好且地势较高的轻粘壤土或沙壤土作圃地,轮作制,不在同一块圃地     

菌根真菌对树苗根部病害的防治作用

采厚环乳牛肝、血红铆钉菇、彩色豆马勃３种外生菌根菌纯培养接种物,对日本落叶松、油松播种苗进行接种试验,测定其对苗木根部病害的生物防治作用。试验表明,３种外生菌根真菌对苗木猝倒病均有的抑制作用。接种不同菌根真菌的松苗猝倒病发病率双对照降低４．０％～５５．９％,苗高、地径、单株鲜重等生长指标提高２．８％～６２．９％,菌根侵染率达８２．０％～９６．０％。     

苗圃松苗立枯病的发生与防治

从3个方面对苗圃松苗木立枯病的发生与防治进行实践性阐述。     

引进木霉菌株T43对立枯病的抑制效果及对苗木的促生作用

把从以色列引进、室内抑菌试验显示对苗木立枯病菌(立枯丝核菌Rhizoctonia solani、腐霉Pythium sp.和腐皮镰刀菌Fusarium oxysporum)具有显著抑制效果的绿木霉Trichoderma virens菌株T43制成不同浓度菌剂,对落叶松Larix sp.和红松Pinus koraiensis 1年生苗木进行室外灌根处理,30 d后测定苗木生长及病害发生情况。结果表明:引进的绿木霉T43菌剂在显著控制落叶松和红松立枯病发生的同时,还显著提高苗木的生长、土壤微生物种群数量及土壤酶活性,该菌株液体菌剂适合落叶松苗木,孢子悬浮液适合红松苗木。     

外生菌根菌对高寒地区松苗猝倒病的防病效应

用外生菌根菌纯培养的固体和液体菌剂在田间落叶松、樟子松幼苗进行人工接种试验,以研究外生菌根菌对松苗猝倒病的生物防治效应。结果:1、兴安落叶松幼苗猝倒病的发病率比对照区降低14.01％～21.91％;樟子松幼苗猝倒病的发病率比对照区降低11.48％～20.26％。2、试验筛选出Suillus grevillei,Boletus sp.,Gomphidius rutilus,Russula foetens 等优良菌种。3、母种培养基以松针(浸膏)培养基、马铃薯葡萄糖麦芽汁琼脂培养基为最佳;原种培养基则以草炭(石至)石玉米粉葡萄糖松针(浸膏)培养基、草炭(石至)石MMN液培养基为最佳。     

松苗猝倒病防治技术

根据多年育苗实践,简述了松苗猝倒病田间识别症状,发病流行规律。提出了防治松树苗木猝倒病应把握土壤处理、种子筛选与处理和苗木管理三个关键技术环节。     

Efficacy of Trichoderma harzianum as a biological control of Fusarium oxysporum in container-grown Douglas-fir seedlings

Inoculating a soilless medium with encapsulated Trichoderma harzianum did not affect any aspect of Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) seed germination or subsequent growth. Results of inoculating medium with a known pathogenic isolate of Fusarium oxysporum alone, or concurrently with T. harzianum, were the same: high levels of damping-off, low amounts of hypocotyl and root disease in midsummer, and significant reductions in height growth. When seedling roots grew through T. harzianum-inoculated medium before growing into a mixture of T. harzianum-F. oxysporum-inoculated medium, mortality was reduced about 50%. Although contamination by resident Fusarium occurred, subsequent root colonization was significantly reduced in T. harzianum-amended growing medium.     

湿地松幼苗根系微生物数量变化规律的研究

采用平板稀释法研究了湿地松幼苗1 a中微生物根系数量的变化规律,为合理的生物防治时期提供科学依据。结果表明:湿地松苗圃土壤中存在着大量的微生物。湿地松幼苗根系的生长和发展可以大大促进其周围微生物的生长,受湿地松根系生长和环境变化等因素的影响,在松苗移栽后的几个月内,根际细菌和真菌的种群数量迅速增加,细菌比真菌的种群增长速度要快。利用生物防治细菌进行苗木猝倒病防治的最佳时期应该是在芽苗移栽后1个月以内。     

苗圃幼苗立枯病防治

简要介绍了苗圃幼苗立枯病的症状、病原及防治方法。     

Aggressiveness of Fusarium oxysporum and F. verticillioides isolates on stone and scots pine under greenhouse conditions

Scots pine (Pinus sylvestris) and Stone pine (Pinus pinea) are two important species used in re-forestation that are subject to damage by damping-off fungi in forest nurseries. Twenty-two isolates of Fusarium oxysporum and F. verticillioides from diseased seedlings of eight different hosts were tested for aggressiveness on seeds and seedlings of both pine species, including the effects on seedling emergence and mortality. Scots pine was more susceptible to damping-off than Stone pine, as indicated both by reduced seedling emergence and elevated seedling mortality. The impact of F. oxysporum and F. verticillioides on seeds and seedlings did not differ significantly for either pine species. Our findings support previous studies that found that these are damping-off pathogens on the studied pines. Whereas most isolates proved to be pathogenic, some isolates of both Fusarium species showed to be non-pathogenic.     

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.     

森保1号防治苗木立枯病药效试验

药效试验证明，在保1号对苗木立枯病的防治效果显著或极显著高于多效唑、多菌灵和增产又，经森保1号处理后，有效控制了立枯病的发生，枯死率显著减少。最佳处理为浸种并喷苗．具体做法如下：在播种前3d，对经催芽处理的种子用700×10－6mg／ml的森保1号浸种4h后播种，待苗木出土3～5d时，用500×10－6mg／ml的森保1号喷苗1～2次。