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1987～1989年进行了农抗120与常用化学杀菌剂防治西瓜枯萎病的药效对比,及不同使用期农抗120的防病效果试验,结果表明,全省多点用300倍农抗120,施药2次,防治西瓜枯萎病的效果平均为83.91±11.86％,比常用化学杀菌剂高23～43％,农抗120的防效与施药时期关系密切,两次灌根时间都应在发病之前,第一次施药时间:直播西瓜在4～5片真叶期,移栽西瓜在苗床期,右,据河南省120个县市,11万亩西瓜的防治示范结果,隔7～10天,进行第二次施药,病株率已控制在0～8％左平均防效为70～95％,每亩挽回西瓜损失200～400公斤。 相似文献
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近年来,黄瓜炭疽病和枯萎病日趋严重,一般减产10～20％。1989年我们在运城市北街应用农抗120进行了药效试验。 防治炭疽病:防前调查,病叶率6.2～8.0％,病情指数1.9～2.5％。5月21日喷农抗120(100ppm),7天后防效63.5％,5月28日再喷一次,第二次喷后防效达76.2％,第三次调查防效达80％,而双效灵Ⅱ防效为55.1％。 相似文献
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我们选用美国氰胺公司生产的百垄通 24％水剂 (下称百垄通 )防除花生田杂草试验，结果药后 32 d对香附子的株防效 64％以上，对其他杂草的株防效 95％以上，总草鲜重防效 97％以上。药后 114 d对香附子株防效 96％以上，对其他杂草株防效 95％以上，总草鲜重防效 97％以上。花生田 1次使用可有效防除禾本科、莎草科和绝大部分阔叶杂草，对香附子有特效，并可抑制香附子块茎的再生。 百垄通用量 30 ml/667 m2以下，对花生生长无明显影响，但 60 ml/667 m2对花生有明显控高作用。对花生茎、叶，即使超过推荐用量 (20～ 30 ml)的 2～ 3倍，… 相似文献
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试验表明40％丙溴磷,32％克虫净乳油1000倍液防治第2代棉铃虫,其杀虫、保顶、保蕾效果优于50％甲胺磷1000倍液的处理,药后1、3、7d防效,40％丙溴磷乳油分别为65.0％、89.5％和84.3％,持效期长,且害虫不易对其产生抗药性;32％克虫净乳油防效分别为85.7％、93.9％和70.6％,速效性好,持效期长,40％速杀硫磷速效性较好,药后1、3d防效为83.3％和92.9％。 相似文献
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几种杀虫剂防治花椰菜小菜蛾试验初报 总被引：1，自引：0，他引：1
田间试验结果袁明：5％氟虫腈悬浮剂(锐劲特)1400倍、10％虫螨腈悬浮剂(除尽)1400倍,20％甲氧虫酰肼悬浮剂(美满)2000倍、4．5%高她氯氰菊酯乳油(诺卡)2000倍液、25％溴氰菊酯乳;由2000倍液、5％氟啶脲乳油(扣太保)1400倍液等杀虫制对花椰菜小菜蛾具有较好的防治效果,且持效期长,对蔬菜安全药后3d防效在84．80％～9296％;药后7d防效在87．92％～95．61％。药后10d防效在87.22％～93．77％。这6种杀虫剂是防活蔬菜小菜蛾的理想药剂。 相似文献
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BACKGROUND: Optimization of biocide use could serve to reduce the risks of biocides on human health. To optimize the risk/benefit ratio, it is important to develop procedures for evaluating the efficacy of biocide formulations. The authors examined the effectiveness of ten pyrethroid insecticide aerosol formulations registered for the household control of flies. Tests were performed using adult Musca domestica L. Knockdown effects and mortality were measured in a test chamber using the manufacturer's recommended discharge time. RESULTS: The knockdown effect varied greatly between aerosols of similar composition. The knockdown 15 min post-treatment was 66-98% for flies placed 120 cm above floor level and 53-96% for flies placed at a height of 180 cm. The KDT(50) values ranged from 2.5 to 9.2 min for flies placed at 120 cm and from 3.2 to 12 min for flies placed at 180 cm. The highest rates of mortality were obtained for a formulation containing S-bioallethrin, permethrin and piperonyl butoxide (81% at 120 cm and 79% at 180 cm). CONCLUSION: Formulations similar in insecticide composition exhibit significant differences in efficacy. Consequently, insecticidal efficacy preregistration evaluations should address not only the efficacy of the active ingredient but also the effectiveness of the formulation. 相似文献
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EM38在土壤盐分分带中的运用研究 总被引：2，自引：0，他引：2
通过分析EM38所测的大地电导率与土水比（1∶5）浸提液电导率之间的相关关系,建立以土壤浸提液电导率（EC）为因变量,大地电导率（EM）为自变量的预测模型。在预测模型建立的基础上,对其精度进行了评定,以确保预测模型在土壤盐分含量预测中的可信度。利用EM38所测的大地电导率来预测土壤中盐分含量,进而分析土壤盐分含量的空间变异性。结果表明：研究区土壤盐分的空间变异特征为表聚性、分带性;并且分析了土壤盐分含量的带状走向,其浅层（0～30 cm）的走向与中层（30～60 cm）、深层（60～90 cm）、底层（90～120 cm）盐带走向的夹角在5°以上,而其他各层相差3°以内,尤其是浅层（0～30 cm）土层的盐分含量走向与植被的带状走向一致,较好地拟合了研究区的地貌变化特征。 相似文献
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通过田间试验,研究了陕西关中塿土区地膜覆盖和秸秆覆盖对表层土壤有机碳、全氮和微生物量碳氮,以及0~200 cm土壤剖面水分及硝态氮分布的影响。结果表明:与不覆盖(NM)相比,白色全膜覆盖(WF)、黑色全膜覆盖(BF)和秸秆覆盖(SM)的表层土壤有机碳分别降低了19.8%、26.3%和20.9%,土壤全氮也分别降低了4.8%、9.6%和10.6%。与NM相比,覆盖处理(WF、BF和SM)可以提高表层(0~20 cm)土壤硝态氮的含量,增加0~40 cm土层的硝态氮累积量(BF的差异不显著),降低40~120 cm土层的硝态氮累积量,但120~200 cm土层的硝态氮累积量差异不显著。SM和BF显著降低0~200 cm土层的硝态氮总累积量,而WF没有显著差异。与NM相比,地膜覆盖(WF和BF)和秸秆覆盖(SM)均可以提高表层0~40 cm土壤水分含量和储水量,但SM的效果低于地膜覆盖;WF可以降低深层土壤水分含量和储水量,而SM和BF与NM无显著差异。0~200 cm土层的总储水量,SM显著高于NM,而地膜覆盖则与NM无显著差异。各覆盖处理均显著降低了表层土壤微生物碳(MBC)和微生物氮(MBN)的含量,与NM相比,MBC分别降低了27.4%、55.4%和66.5%,MBN分别降低了4.6%、4.8%和6.8%。地膜覆盖(WF和BF)和秸秆覆盖(SM)均能够加速土壤有机碳的矿化分解,降低土壤微生物,减少土壤硝态氮的深层淋溶,其对塿土碳氮和水分的长期影响值得进一步研究关注。 相似文献
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Effects of temperature, humidity, rewetting and removal of deposits on penetration of NAA [2-(1-naphthyl)acetic acid] through isolated tomato (Lycopersicon esculentum Mill) fruit cuticles were studied using a finite dose diffusion system. In this system, an aqueous 5-microliter droplet (0.1 mM NAA in 20 mM citric acid buffer) is applied to the outer surface of a cuticle, which is mounted in a glass diffusion half-cell. The cell wall surface is in contact with a receiver solution (20 mM citrate). Penetration is monitored by repeated sampling of the receiver solution. Droplets appeared dry on visual inspection within 1 h of application, but significant NAA penetration continued after droplet drying. Maximum rates of NAA penetration increased exponentially as temperature was increased (from 5 degrees to 35 degrees C), the energy of activation averaging 153 (+/- 11.6)kJ mol-1. At 35 degrees C, penetration reached a plateau within 10 h of application (at 91.1 (+/- 1.0)% of dose applied) while at 5 degrees C penetration after 800 h reached only 30.2 (+/- 7.5)%. Increasing relative humidity from 20 to 80% increased maximum rates [from 1.0 (+/- 0.21) to 2.7 (+/- 0.80)% h-1] and penetration at 120 h after application [from 36.8 (+/- 2.1) to 64.3 (+/- 3.7)%]. Rewetting deposits at 120, 240 and 360 h after application resulted in increased NAA penetration. However, amounts and rates of NAA penetration progressively decreased with each subsequent rewetting. Removal of deposits by cellulose acetate stripping at various times after droplet application resulted in a rapid decrease in NAA penetration. NAA penetration following deposit removal was always less than 6.1% of the amount of NAA applied and averaged 0.5 (+/- 0.2)% when deposits were removed immediately after droplet drying. 相似文献
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博尔塔拉河下游河岸带土壤养分特征及其相关性分析 总被引：2，自引：0，他引：2
对博尔塔拉河下游河岸带土壤有机质、全氮、速效磷、速效钾、pH进行了分析。结果表明：① 土壤有机质在表层和80 cm土层属于强变异;20 cm、40 cm和60 cm土层属于中等变异。② 有机质含量为0.03%～4.19%,差值较大;不同深度土壤有机质含量从表层到深层逐渐减少,递减规律显著;5层（0~10 cm、20 cm、40 cm、60 cm和80 cm）土壤之间有机质含量垂直方向的相关性特征显示,60 cm深度与其他层次土壤有机质含量呈弱正和弱负相关,0 cm与80 cm、20 cm与40 cm之间的相关性极显著。③ 土壤有机质含量与pH、速效钾含量呈负相关,与速效磷含量呈正相关,与全氮呈极显著正相关（[WTBX]R[WTBZ]=0.934）。④ 通过对土壤样品养分含量分级显示,土壤有机质含量和速效磷含量平均值分别为0.44%和1.99 mg•kg-1,均属于极缺乏型;全氮含量和速效钾含量平均为0.07%和39.78 mg•kg-1,属于很缺乏型;pH平均为7.47,属于中性。 相似文献
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从玉米成株期根、茎组织中分离获得232株内生细菌,在离体条件下筛选获得20株对玉米纹枯病菌具有显著拮抗作用的内生细菌,其中7株为枯草芽孢杆菌,占拮抗菌株的35%.B20-120、B20-006、B20-122、B21-072、B21-016、B20-070等6株拮抗细菌的发酵液对玉米种子萌发没有影响,进一步对其内生性(以抗利福平120 mg·mL-1为标记)及其对玉米的促生作用和玉米纹枯病的防治效果进行了研究.结果表明,供试6个拮抗菌株对玉米生长没有抑制作用,有的甚至有促进作用,并且能在体内繁殖,具可转移性.拮抗菌株B20-006和B20-120对纹枯病的防治效果最好,菌液浸种处理苗期防治效果分别为67.9%和62.3%,成株期分别为40.2%和39.1%. 相似文献
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Patterns, magnitude, and controlling factors of hydraulic redistribution of soil water by Tamarix ramosissima roots 总被引：1，自引：0，他引：1
Tamarix spp.(Saltcedar)is a facultative phreatophyte that can tolerate drought when groundwater is not accessed.In addition to deep water uptake,hydraulic redistribution(HR)is another factor contributing to the drought tolerance of Tamarix spp.In this study,data on soil volumetric moisture content(θ),lateral root sap flow,and relevant climate variables were used to investigate the patterns,magnitude,and controlling factors of HR of soil water by roots of Tamarix ramosissima Ledeb.in an extremely arid land in Northwest China.Results showed evident diurnal fluctuations in θ at the depths of 30 and 50 cm,indicating "hydraulic lift"(HL).θ increased remarkably at 10 and 140 cm but decreased at 30 and 50 cm and slightly changed at 80 cm after rainfall,suggesting a possible "hydraulic descent"(HD).However,no direct evidence was observed in the negative flow of lateral roots,supporting HR(including HL and HD)of T.ramosissima.The HR pathway unlikely occurred via lateral roots;instead,HR possibly occurred through adventitious roots with a diameter of 2-5 mm and a length of 60-100 cm.HR at depths of 20-60 cm ranged from 0.01-1.77 mm/d with an average of 0.43 mm/d,which accounted for an average of 22% of the estimated seasonal total water depletion at 0-160 cm during the growing season.The climate factors,particularly vapor pressure deficit and soil water potential gradient,accounted for at least 33% and 45% of HR variations with depths and years,respectively.In summary,T.ramosissima can be added to the wide list of existing species involved in HR.High levels of HR may represent a considerable fraction of daily soil water depletion and substantially improve plant water status.HR could vary tremendously in terms of years and depths,and this variation could be attributed to climate factors and soil water potential gradient. 相似文献
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以14C标记碳酸钡(Ba14CO3)为起始物,采用4步反应合成14C-1,2,4-三唑,总强度为5.813 1 mci,比强为15.53 μci/mg, 纯度大于99%,放化收率84.21%。在此基础上,参照文献报道的有关腈菌唑合成的方法,以4-氯苯乙腈为原料,经取代、缩合等3步反应合成了14C-腈菌唑,其总强度为0.556 6 mci,比强为2.53 μci/mg,纯度大于96%,放化收率85.4%。应用同位素示踪技术研究了14C-腈菌唑在2~3叶期小麦幼苗上的吸收、分布和传导。结果表明,根部给药后6~120 h,小麦根部放射性物质分布比例由59.88%下降为 24.87%;在幼苗茎基部和叶片中,放射性物质分布比例分别由14.18%、1.19%上升为 19.47%和33.75%;14C-腈菌唑被小麦幼苗吸收后向顶传导的速度很快,在叶片中的分布和积累与根部给药时间呈正相关,放射强度由2.94×10-6 μci上升为322.72×10-6 μci。放射性自显影表明,根部给药后120 h,14C-腈菌唑可以内吸传导到整个小麦植株。 相似文献