简介:近年来,由于不合理的防治措施,黄纹竹斑蛾已成为危害毛竹叶片的主要害虫。为探索有效控制黄纹竹斑蛾危害的无公害防治措施,试验研究了不同浓度的6种植物源杀虫剂:0.5%藜芦碱可溶性液、1%苦皮藤素可溶液、4%鱼藤酮乳油、1.5%苦参碱可溶液、1.2%烟碱·苦参碱可溶液和1.1%苦参碱粉剂对黄纹竹斑蛾幼虫的防治效果,其中前5种药剂采用喷烟技术施药,后一种药剂采用喷粉技术施药。结果表明:施药后3d,6种药剂的防治效果均达90%以上;0.5%藜芦碱可溶性液、1%苦皮藤素可溶液和4%鱼藤酮乳油的田间最佳用药浓度是原药与0号柴油容积比为1:40,用药量为1200mL/hm^2;1.5%苦参碱可溶液、1.2%烟碱·苦参碱可溶液田间最佳用药浓度是原药与0号柴油容积比为1:9,用药量为800mL/hm^2;1.1%苦参碱粉剂田间最佳用药量为22.5kg/hm^2。上述6种植物源杀虫剂均可作为无公害防治黄纹竹斑蛾幼虫的药剂,在黄纹竹斑蛾幼虫危害时施用。
简介:本文采用萝卜子叶扩张法,萝卜、小麦和黄瓜的幼苗生长法,分别对原竹醋液和中和竹醋液进行室内生物活性筛选试验。结果表明:(1)低浓度(<500mg/L),具有植物生长调节剂功效,其功能与2,4-D类、激素类除草剂相似;高浓度竹醋液(2000~5000mg/L)抑制作物生长,具有除草剂活性;也与植物生长调节剂GA3和6-BA具有相似的功效;(2)中和竹醋液的效果明显高于原竹醋液;(3)几种筛选指示物的敏感性从高到低的顺序为:萝卜子叶>黄瓜根茎长>萝卜根茎长>小麦根茎长,其中对于黄瓜、萝卜和小麦,根长敏感性均高于茎长。对原竹醋液和中和竹醋液在苹果、柑橘、草莓等作物上进行应用试验。表明:竹醋液不仅显著地提高农林作物的产量;具有明显改善叶片质量,延长叶片寿命,提高果实硬度从而改善果实的储藏品质,改善果品的内在品质和外观品质等功能;在调节果实成熟期减少锈斑面积、落叶、落果和病害等方面均有显著作用。
简介:以海南省万宁市木麻黄林、马占相思林、桉树林、次生林和椰子林5种森林植被为研究对象,对样地开展0-100cm土层的化学性质测定对比分析。结果表明:5种植被土壤化学性质存在差异性,其中土壤pH介于4.62-9.06间,除了木麻黄林属于碱性土壤外,其它4种林分均属于酸性土壤;土壤有机质含量介于1.79-15.02g/kg,均属于低有机质含量土壤;土壤全氮含量介于0.10-0.78g/kg,属于低氮肥力土壤;土壤全磷介于0.2-1.1g/kg,椰子林土壤全磷含量最高;土壤全钾介于3.7-29.2g/kg,以次生林最高,木麻黄林次之,椰子林和桉树林之间差异不大,马占相思林最低;土壤有效磷含量介于1.62-290.80mg/kg,大小顺序为椰子林〉木麻黄林〉桉树林〉次生林〉相思林;土壤速效钾含量介于4.50-107.13mg/kg,大小顺序为马占相思林〉次生林〉椰子林〉桉树林〉木麻黄林;土壤硝态氮含量介于1.23-18.16mg/kg,大小顺序为马占相思林〉椰子林〉次生林〉桉树林〉木麻黄林;土壤铵态氮含量介于1.78-27.27mg/kg,以马占相思林最高,桉树林次之,椰子林和次生林之间差异不大,木麻黄林最低。该研究从不同土壤土层营养成分方面进行分析,了解木麻黄林、马占相思林、桉树林、次生林和椰子林土壤营养成分的现状情况,旨在揭示万宁市不同林分的土壤养分特征,为万宁市森林的可持续性经营提供参考。
简介:TheimpactsofelevatedtemperatureandCO2onyoungsilverbirch(BetulapendulaRoth)saplingsafter0,25,50or75%artificialdefoliationwereassessedbymeasuringplantheightanddrymassofabovegroundcompartmentsandrootsandvariousmorphologicalandphysiologicalvariables.Defoliationeitherincreasedordecreasedplantgrowthdependingontheseverityofdamageandtheclimatictreatment.At21Cand400mgL-1CO2,defoliatedplantswerenotabletocompensateforthelostfoliage,butgrowthcompensationandadaptationtothechangedconditionsweregreater;growthofyoungdefoliatedsilverbirchsaplingsincreased,whichledtoincreasedheightandatendencytoenhancefinalabovegroundandrootbiomassandleafnitrogenandcarboncontentcomparedtothenondefoliatedcontrols.Nevertheless,theshort-termeffectofthedifferentclimaticconditionsdidnotresultinasignificantovergrowthofdefoliatedplants.AslightincreaseintemperatureandCO2werethemostacceptableconditionsfordefoliatedplants;however,a4CincreasewithcorrespondinglyhigherCO2wasmorestressfulasshownbylessgrowthinheightandbiomassallocationtoleaves,stemsandroots.Thefindingsfromthepilotexperimentaremoreapplicabletoyoungbirchtrees,butstressonyoungtreesmaybereflectedinfuturetreegrowth.
简介:SiberianmothDendcrolimussuperanssibiricusTschetw.isthemainimportantinsectpestnotonlyinSiberianconiferoustaiga,butitoftenformsfociofmassreproductioninlarchstandsintheRussianFarEast.ThisarticlehasdescribedoutbreaksoftheSiberianmothandotherinsectpestssince1960tillnow.
简介:Background:Thispaperexploredthelong-term,ceteris-paribuseffectsofpotentialCO,fertilizationontheglobalforestsector.BasedonthefindingsofNorbyetal.(PNAS2005,102(50))aboutforestresponsetoelevated[CO_2].Methods:ForestproductivitywasincreasedintheGlobalForestProductsModel(GFPM)inproportiontotherising[CO.,]projectedintheIPCCscenarioA1B,A2,andB2.Projectionsoftheforestareaandforeststockandoftheproduction,consumption,prices,andtradeofproductsrangingfromfuelwoodtopaperandpaperboardwereobtainedwiththeGFPMforeachscenario,withandwithoutCO_2fertilizationbeginningin2011andupto2065.Results:C02fertilizationincreasedwoodsupply,leadingtolowerwoodpriceswhichinturninducedmodestlowerpricesofendproductsandhigherglobalconsumption.However,productionandvalueaddedinindustriesdecreasedinsomeregionsduetotherelativecompetitiveadvantagesandtothevaryingregionaleffectsofCO_2fertilization.Conclusion:ThemaineffectofCO,fertilizationwastoraisetheleveloftheworldforeststockin2065by9to10%forscenariosA2andB2andby20%forscenarioA1B.Theriseinforeststockinducedbyfertilizationwasinpartcounteractedbyitsstimulationofthewoodsupplywhichresultedinlowerwoodpricesandincreasedharvests.