5种药剂对樟子松苗猝倒病的防治效果研究

为筛选出对樟子松苗木猝倒病防治效果较好的药剂,本试验选择了百菌清、甲基硫菌灵、多菌灵、代森锰锌、敌克松5种药剂进行试验,测定5种药剂不同剂量处理对樟子松苗木猝倒病的防治效果。试验结果表明,在樟子松出苗后进行药剂喷施,试验的5种药剂均对樟子松苗木猝倒病表现出一定的防治效果。其中,敌克松对樟子松苗木猝倒病的防治效果最高,使用70%敌克松可溶性粉剂稀释800倍液处理后对樟子松树苗木猝倒病的防效达84.8%,多菌灵的防治效果次之,使用80%多菌灵可湿性粉剂稀释1 200倍液处理后对樟子松苗木猝倒病的防效达81.6%。百菌清、甲基硫菌灵、代森锰锌对樟子松苗木猝倒病的防治效果较低,但对樟子松苗木猝倒病也具有一定的防效。生产中建议在樟子松出苗后,使用敌克松、多菌灵喷雾进行处理防治樟子松苗木猝倒病。     

云南拟单性木兰苗木猝倒病防治试验

针对云南森林自然中心苗圃和云南林业学校苗圃在培育云南拟单性木兰苗时,苗木受猝倒病危害较为严重的特点,通过选用未耕作过的基质培育苗木与选用苗圃地基质培育苗木进行对比试验,用50%多菌灵可湿性粉剂1000倍液和0 5∶1的波尔多液200倍液交替使用防治苗木猝倒病与其它药物防治苗木猝倒病进行对比试验,通过试验发现前者对防治苗木猝倒病有较好防治效果,苗木发病率控制在18%,发病苗木死亡率控制在8%,在生产中应用成效显著。     

六六六粉防治松、杉苗木猝倒病

猝倒病是松、杉苗期的主要病害之一。苗木出土两个月左右,一旦发生蔓延,将造成大量苗木倒伏死亡,严重地影响了出苗率和苗木的质量。1973年全县受猝倒病危害而死亡的苗木达40%以上。因此,开展防治松、杉苗木猝倒病的研究,是育苗技术中的一个环节。1972年,在湫山公社道林辽水库杉木苗圃进行了六六六粉防治猝倒病的试验,观察结果,效果良好。为了探讨六六六粉防治松、杉猝倒病的效果,于1973年进行了室内病菌接种和室外苗圃防治试验,证明六六六粉剂对猝倒病病菌具有毒杀作用。因而,六六六粉可以防治猝倒病的发生和蔓延。     

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。     

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。     

落叶松苗猝倒病早期简易鉴别法

<正>感染猝倒病的苗木,常表现出幼苗倒伏,根茎或种芽腐烂等症状。在生产中一般根据这些症状判断其发生并进行防治,但具有这些症状的苗木均已不能正常生长。现介绍一种早期确定落叶松苗木猝倒病的方法,供参考。 正常生长的苗木,在木质化以前地下部分是白色的,如果苗木染上了猝倒病,染病前期根茎下0-1.5cm处出现暗灰色圆圈,据此可早     

思茅松猝倒病防治方法简介

苗木猝倒病又称苗木立枯病,云南各地都有发生,而且发病率都很高,严重的甚至绝产,是育苗中一大危害。现介绍思茅松猝倒病的病因和几种防治方法,供营林工作者参考。1猝倒病病原苗木猝倒病主要致病原是真菌中半知菌的茄丝孢菌、腐皮镰孢菌和尖孢镰孢菌、鞭毛菌的终极腐霉和瓜果腐霉,有时还有半知菌的细链格子孢菌等。一些非生物因素也能引起猝倒病,如苗圃地过于阴凉、潮湿,低洼积水、排水不好,土壤粘重、板结,播种时盖土过厚,草帘揭除过迟或浇水过勤等,也能导致苗木猝倒病的发生。2防治猝倒病的方法2.1土壤消毒土壤消毒一般用柴草实行3烧3挖;也…     

怎样用新洁尔灭防治苗木猝倒病

防治苗木猝倒病,是育苗者的一项重要工作。一往人们采用多菌灵等药物防治苗木猝倒病,但效果不够理想。而采用新洁尔灭防治苗木猝倒病,每亩用量仅40克(合人民币0.13元左右),比用多菌灵每亩可节约成本费0.47元。同时可降低苗木发病率13.2～16.4％。每亩减少发病株数约4～5千株。新洁尔灭的使用方法很简单。将5％的医用新洁尔灭配制成1:2000倍液后,喷洒苗木即可达到     

苗木猝倒病及研究进展

苗木猝倒病是1种危害针叶树和阔叶树发芽种子和幼苗的病害,能引起幼嫩组织的腐烂、萎蔫和种苗死亡。笔者就苗木猝倒病的分布和寄主、病原、症状、病害发展、管理和最新研究进展进行了描述。     

学习外省森林病虫害防治经验

一、六六六粉防治松、杉苗木猝倒病浙江省仙居县农林局报导:在湫山公社道林辽水库杉木苗圃进行了六六六粉防治猝倒病的试验,观察结果,效果较好。苗圃的土壤消毒处理:1972—73年,先后在两个苗圃试验。在育苗前,每亩用6—8斤六六六粉土壤消毒。1972年6月     

不同轻基质组配与密度对枫香苗木生长的影响

枫香是在观赏、药用、用材方面都有着重要作用且颇具潜力的造林绿化树种,为了加快培育优质的枫香苗木,笔者根据枫香的生长特性,采用不同的轻基质组配、不同的栽种密度和是否进行苗期大小苗分级的方法设置7个处理,对枫香苗木进行容器育苗试验。结果表明：使用LQ基质的处理组在种苗保存率、Ⅰ级苗率、合格苗出圃率、每平方米合格苗出圃数、平均苗高和平均地径等方面均高于使用SX基质或LZ基质的处理组。在轻基质组配和分盘处理相同的情况下,采用143株/m^2的密度培育枫香容器苗,较采用195株/m^2、238株/m^2密度培育枫香苗有着更高的保存率、Ⅰ级苗率和合格苗出圃率,且平均苗高、地径以及苗木整齐度也更优。而进行大小苗分级培养的处理组与未分级培养的处理组在种苗成活率、合格苗出圃率、每平方米合格苗出圃数等指标上差距不大,但进行分级处理后的大苗盘的Ⅰ级苗率远高于未分级组和小苗组。     

Effects of soil and stem base heating on survival, resprouting and gas exchange of Acer and Quercus seedlings

Acer rubrum L., A. saccharum Marsh., Quercus alba L. and Q. rubra L. seedlings subjected to soil and stem base heat treatments showed rapid declines in rates of transpiration and photosynthesis. Reductions in photosynthetic rate were partly attributable to mesophyll inhibition. Quercus seedlings were less able to maintain transpiration and photosynthesis after heat treatment than Acer seedlings. Declines in rates of transpiration and photosynthesis of Quercus seedlings were observed 1 h after heat treatment and became more pronounced over time. In contrast, rates of transpiration and photosynthesis of Acer seedlings initially declined in response to heat treatment, partially recovered after one or two days, but then declined again six to eight days after the heat treatment. Observed changes in leaf water potential after heating were small, suggesting that hydraulic factors were not the primary signal eliciting the gas exchange response to soil and stem heating. Ultimately, the heat treatments caused stem die-back of most seedlings. For all species, seedlings that resprouted had a greater chance of surviving heat stress than seedlings that did not resprout. Despite the rapid loss of photosynthetic capacity in response to heat treatment in Quercus seedlings, survival was higher in Quercus seedlings than in Acer seedlings, and was associated with a greater capacity for resprouting. We suggest that the reduced allocation of resources toward recovery of photosynthesis in existing Quercus stems after heat stress is a physiological mechanism that facilitates resprouting and hence survival of Quercus seedlings after fire.     

The effects of acid rain and ozone on biomass and leaf area parameters of shortleaf pine (Pinus echinata Mill.)

Shortleaf pine (Pinus echinata Mill.) seedlings in 24 open-top chambers were exposed to combinations of ozone (carbon-filtered (control), ambient, 1.7 x ambient, and 2.5 x ambient) and acidic precipitation (pH 5.3, 4.3 and 3.3) for 16 months (1989 harvest) or 28 months (1990 harvest). Although the effects of acid rain were generally not significant, there was a trend toward increased aboveground biomass and leaf area in seedlings subjected to the low pH treatments. Because N concentrations in the soils generally increased with decreasing pH, we concluded that the effects of acid rain on aboveground biomass and leaf area were a consequence of an increasing concentration of soil N. In the 1989 harvest, seedlings in the 2.5 x ambient ozone treatment had significantly less biomass in all aboveground plant components and significantly less total leaf area than seedlings in the 1.7 x ambient ozone treatment. In the 1990 harvest, there were no significant effects of ozone on total aboveground biomass, although there was a trend toward reduced biomass in seedlings in the 2.5 x ambient ozone treatment. Both total leaf area and leaf biomass were significantly less in seedlings exposed to 2.5 x ambient ozone for 28 months than in both control seedlings and seedlings in the 1.7 x ambient ozone treatment. The greater, but not always significant, aboveground biomass and leaf area of seedlings in the 1.7 x ambient ozone treatment compared with control seedlings may be associated with the observed increase in soil nitrate concentration as a result of increased rates of leaf senescence and litterfall.     

红豆树苗木根瘤及其对生长的影响

红豆树根瘤的形成时间和根瘤的数量与圃地土壤的质量有关,在土壤水肥条件好的环境中,1 a生苗木中的根瘤少见,且根瘤个体极小;在土壤较贫瘠的圃地中,红豆树根瘤十分发达,数量多且形成时间早。红豆树根瘤能够促进苗木生长,有根瘤生长比无根瘤生长的1年生红豆树植株中,根系的干物质增长率46%、根系鲜重的增长率41.9%、茎干物质增长率40.3%、植株总干物质的增长率35.0%、植株总鲜重增长率22.4%、植株叶的干物质增长率14.8%。截根处理有助于根瘤菌感染苗木植株,苗木生长更健壮:截根处理的苗木径高比为4.1%,未截根处理的为3.4%;截根处理促进根系的发育,截根处理的侧根总长度47cm/株、未截根处理的侧根总长度为26cm/株、侧根增加率为80.8%,截根处理的须根总长度228cm/株、未截根处理的侧根总长度为102cm/株、须根增加比率123.5%;截根处理促进苗木根幅的扩大,比未截根处理的根幅增大27.3%。     

Effects of tip-pruning treatment on source-sink regulation of Catharanthus roseus seedlings

Introduction The photo-assimilates produced in the source organs are transported into the sink organs mostly in the form of sucrose. Sucrose is released from the sieve elements of the phloem into the apoplast by a sucrose transporter, where it is irrevers…     

落叶松菌根苗培育及造林技术应用

为培育落叶松菌根苗木,营造速生丰产林,应遵循一定的操作规程,采取相应的技术措施。即严格把好菌种关,进行常规种子处理及苗床准备,对播种苗、容器苗、移植苗、扦插苗接菌,实现苗木菌根化,加强菌根苗管理。在菌根苗造林起苗时,应避免菌根的脱落,并对菌根苗分级,做到适地适树适菌,只有按科学合理的方法操作管理,才能有效地发挥菌根的作用。     

Physiological responses of seedlings of two oak species to flooding stress

The physiological responses of 2-year-old seedlings of Nuttall＇s oak （Quercus nuttallii） and Southern red oak （Q.falcata） with two treatments i.e., deep-drowning and shallow-drowning, were studied. Taxodium distichum was selected as a control. The survival rates of seedlings were calculated, the photosynthetic indices were detected by Licor-6400 photosynthetic system instrument, and the root activities of seedlings were tested by the method of triphenyltetrazolium chloride （TTC）. Results showed that： 1） By experiencing flooding for 76 d and recovering for 60 d after water was drained off, all seedlings survived under the shallow-drowning treatment. None of Q. falcata seedlings died in the deep-drowning treatment until the 49th day. The survival rate of Q. falcata in the deep-drowning treatment was 30%. 2） Within 61 d of waterlogging treatments, the net photosynthetic rate （Pn）, stomatal conductance （gs） and transpiration rate （Tr） showed a tendency of declining, but intercellular concentration of CO2 （Ci） increased. With the prolongation of flooding stress, the extents of variation for all indices under deep-drowning treatment were larger than those under the shallow-drowning treatment. The variation of Q. falcata in flooding stress was larger than that of Q. nuttallii. 3） The root vigor and alcohol dehydrogenase （ADH） activities were detected at the 61st day in flooding stress. Waterlogging obviously inhibited root activities. Shallow-drowning made root vigor of Q. nuttallii decreased by 11.7%, and for Q. falcata, by 51.88%. Shallow-drowning treatment had no remarkable effects on ADH activities of seedlings, but deep-drowning increased those of Q. nuttallii seedlings by 227.24%, and decreased those of Q. falcata seedlings by 59.22% in the meantime. We conclude that Q. nuttallii had a stronger waterlogging resistance than Q. falcata, but weaker than T. distichum.     

Effects of brassinolide on the survival,growth and drought resistance of <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> seedlings under water-stress

We conducted field and pot experiments to investigate the effects of brassinolide on 1-year-old Robinia pseudoacacia L. seedlings. In the field experiment, seedling roots were soaked in brassinolide solutions containing 0–0.4 mg/l pure brassinolide before planting. Survival and growth of the seedlings were determined 8 months later. The results showed that soaking roots in brassinolide prior to planting significantly increased the survival and growth of seedlings. The best results were in the 0.2 mg/l brassinolide treatment. In the pot experiment, roots were soaked in 0–0.4 mg/l brassinolide before planting followed by a foliar application of brassinolide when the seedlings leafed out. After the seedlings were established, the soil water content in the pots was regulated to simulate drought conditions and various physiological parameters were measured. The results showed that treatment with 0.2 mg/l brassinolide decreased the transpiration rate, stomatal conductance and malondialdehyde (MDA) content of seedlings growing under moderate or severe water stress compared to untreated seedlings. Leaf water content, predawn water potential, soluble sugar content, free proline content, and superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were all greater in water-stressed seedlings in the 0.2 mg/l brassinolide treatment compared to the control. The results indicate that the application of brassinolide can ameliorate the effects of water stress and enhance drought resistance of Robinia seedlings. Treatment of seedlings with brassinolide may be a useful management tool for afforestation projects in arid and semiarid areas.     

Acclimation of loblolly pine (Pinus taeda) seedlings to high temperatures

To determine the extent to which loblolly pine seedlings (Pinus taeda L.) acclimate to high temperatures, seedlings from three provenances-southeastern Texas (mean annual temperature 20.3 degrees C), southwestern Arkansas (mean annual temperature 16.2 degrees C) and Chesapeake, Maryland (mean annual temperature 12.8 degrees C)-were grown at constant temperatures of 25, 30, 35 or 40 degrees C in growth chambers. After two months, only 14% of the seedlings in the 40 degrees C treatment survived, so the treatment was dropped from the experiment. Provenance and family differences were not significant for most measured variables. Total biomass was similar in the 25 and 30 degrees C treatments, and less in the 35 degrees C treatment. Foliage biomass was higher, and root biomass lower, in the 30 degrees C treatment compared with the 25 degrees C treatment. Net photosynthesis and dark respiration of all seedlings were measured at 25, 30 and 35 degrees C. Both net photosynthesis and dark respiration exhibited acclimation to the temperature at which the seedlings were grown. For each temperature treatment, the highest rate of net photosynthesis was measured at the growth temperature. Dark respiration rates increased with increasing measurement temperature, but the basal rate of respiration, measured at 25 degrees C, decreased from 0.617 &mgr;mol m(-2) s(-1) in the 25 degrees C treatment to 0.348 &mgr;mol m(-2) s(-1) in the 35 degrees C treatment, resulting in less carbon loss in the higher temperature treatments than if the seedlings had not acclimated to the growth conditions. Temperature acclimation, particularly of dark respiration, may explain why total biomass of seedlings grown at 30 degrees C was similar to that of seedlings grown at 25 degrees C.     

Survival and growth of drought hardened <Emphasis Type="Italic">Eucalyptus pilularis</Emphasis> Sm. seedlings and vegetative cuttings

Forestry requires low mortality of transplanted seedlings. Mortality shortly after planting is often associated with inadequate hydration of transplants. Seedlings can be hardened to the drought conditions they may experience after transplanting by exposing them to controlled drought conditions in the nursery. Eucalyptus pilularis Sm. seedlings were drought hardened by providing nil (severe treatment) or half (mild treatment) the daily irrigation routinely received (control treatment) for up to two non-consecutive days per week during the last 4 weeks of growth in the nursery. Drought hardening reduced stem diameter, seedling leaf area, leaf area per root biomass and seedling quality measured by the Dickson quality index, but increased root:shoot ratio. Hardened seedlings had lower stomatal conductance and leaf water potential on the days they received less irrigation that the control treatment. Hardened seedlings had greater stomatal conductance and were less water stressed than seedlings experiencing drought for the first time indicating hardened seedlings had adjusted physiologically to drought. Survival after transplanting in the controlled drought environment in a glasshouse was enhanced by the hardening treatments. Non hardened seedlings that had had their upper leaves manually removed immediately prior to transplanting to reduce leaf area (top-clipped) had similar survival to hardened seedlings. Stomatal conductance and leaf water potential after transplanting were higher in hardened and top-clipped seedlings than unhardened control seedlings or vegetative cuttings. Survival in the field trial was over 95% for all treatments, possibly as rain fell within 4 days of planting and follow-up rain occurred in the subsequent weeks. Neither the hardened or top-clipped seedlings planted in the field trial had reduced growth, increased propensity to form double leaders or worse stem form than control seedlings when measured at age 3 years.