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大豆食叶性害虫食叶量的初步研究 总被引：1，自引：0，他引：1
我地大豆食叶性害虫主要包括豆天蛾(Clanis bilineata Walker)、银纹夜蛾(Plu-sia agnata Stgr.)、大豆小夜蛾(Amyna oeto(Guenee)),云纹夜蛾(MocisundAta(Fabricius))、棉大造桥虫(Ascotis selenaria Sehif.et Denis)、长须夜蛾(Hypena rostralis L.)等几种。为了摸清其为害习性及食叶量,给制定统一的防治指标提供依据,我们于1986—1987年对大豆食叶性害虫的为害习性进行了观察,并分别在田间和 相似文献
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近年来大豆除草剂的施用面积逐年增加,在生产中时常出现人为原因造成的除草效果差、作物发生药害等问题,为此就大豆田如何科学使用除草剂谈一些看法. 1针对作物田间杂草种类选用适宜的除草剂品种 任何品种除草剂都有其一定的杀草谱,有防阔叶的,有防窄叶的(禾本科、莎草科),也有部分窄叶、阔叶草兼防的,但一种除草剂即使再好也不可能有效地防治田间所有杂草,所以,使用除草剂之前要弄清楚田间有些什么杂草,要分清哪些是主要杂草,哪些是次要杂草,要根据田间主要杂草兼防次要杂草的原则来选择除草剂. 相似文献
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大豆食叶性害虫主要有大豆造桥虫及豆天蛾。大豆造桥虫的优势种是银纹夜蛾和大豆小夜蛾,长须夜蛾、云纹夜蛾等也造成一定的为害。过去所提大豆造桥虫的防治指标是一个混合概念,豆天蛾尚无统一的防治指标。为判定更为科学的化学防治指标,于1984年以来,对银纹夜蛾、大豆小夜蛾和豆天蛾幼虫为害损失和防治指标进行了研究,通过5年的试验研究,拟定出了不同产量水平下,几种食叶性害虫混合发生时的防治指标。本防治指标是根据经济允许损失率,通过实验分析而制订出的。其方法是,首先根据 相似文献
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一、前言大豆食心虫防治指标是以三增(增产、增收、增加天敌),三减(减轻病虫危害、减少农药用量、减少对环境污染)为目的的综合防治的组成部分。对于大豆食心虫来说,虫食率达到多少,产量损失和经济损失达到什么水平,才必须预报准备防治呢?因此,大豆食心虫的防治指标,是结合预报使用的,其实质是预报的防治指标。为此,在对大豆食心虫危害产量损失进行研究基础上,结合品质下降经济损失,同时考虑到与预报结合使用,提出了大豆食心虫预报防治指标,通过多年指 相似文献
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橘全爪螨有螨叶率防治指标的初步研究 总被引：1，自引：1，他引：0
橘全爪螨 (ＰａｎｏｎｙｃｈｕｓｃｉｔｒｉＭｃｇｒｅｇｏｒ)是为害柑橘的一种主要害虫 ,常因防治不及时而造成减产和品质下降。如何快速准确地实施虫情调查监测 ,适时指导药剂防治 ,是橘全爪螨综合治理的一个重要环节。但由于国内现有关于橘全爪螨防治指标的研究均以平均每叶头数来度量 ,而在实际调查时又因其个体小 ,数量多 ,使得计数工作非常繁琐 ,在防治实践中难以推行。为简化橘全爪螨的调查方法 ,根据大量的田间调查资料 ,力图建立起橘全爪螨平均每叶头数与有螨叶率之间的回归模型 ,使得橘全爪螨的种群监测可以通过调查有螨叶率来实… 相似文献
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山西省苹果园山楂叶螨对5种杀虫剂抗药性监测 总被引：1，自引：0，他引：1
为了明确山西省苹果园山楂叶螨(Amphitetranychus viennensis Zacher)对化学杀虫剂的抗性现状及发展趋势,本文采用玻片浸渍法建立了山楂叶螨相对敏感种群对5种杀虫剂的敏感基线,连续3年(2013-2015年)监测了采自山西省苹果主产区运城苹果园的山楂叶螨对5种杀虫剂的抗性水平及变化动态。监测结果表明:田间监测种群对阿维菌素和三唑锡均处于敏感性下降及低水平抗性阶段,对哒螨灵和噻螨酮的抗性由低水平抗性升至中等水平抗性,对炔螨特处于低水平抗性。田间防治山楂叶螨时,哒螨灵与噻螨酮应淘汰不再使用,阿维菌素、三唑锡、炔螨特则应注意减少用药量及轮换用药,以延缓产生更高水平的抗药性。 相似文献
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为明确草地贪夜蛾Spodoptera frugiperda对我国玉米产量造成的损失,并制订相应的防治指标,在玉米不同生育期分别接入不同数量的草地贪夜蛾3龄幼虫,研究其为害玉米后对产量和其他相关指标造成的影响,建立不同生育期产量损失与不同为害率之间的回归方程。结果显示,大喇叭口期接虫对玉米成株期株高有显著影响,玉米各生长时期接入不同数量草地贪夜蛾后对产量损失均有显著影响。根据防治成本及玉米产量等指标计算出国内玉米的经济危害允许水平为5.56%。利用回归方程计算出玉米小喇叭口期、大喇叭口期以及吐丝期的防治指标分别是为害率达8.72%、7.99%和6.17%。 相似文献
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为制定大豆蚜Aphis glycines阶段特异性经济阈值,于2015—2018年连续4年开展田间试验,通过定点、定株调查和产量测定,运用回归分析法研究大豆4个特定生长阶段下不同密度大豆蚜侵染对其产量损失的影响。结果表明,在大豆4叶期—初花期阶段,大豆蚜侵染的累计蚜日及其种群增长率均最大,分别达到40 900头·日和0.184,大豆产量损失率也最高,达到了60.96%。大豆蚜的侵染密度与产量损失率在大豆出苗期—4叶期和4叶期—初花期阶段使用线性模型拟合的优度最高,在初花期—初荚期和初荚期—鼓粒期阶段使用对数曲线模型拟合的优度最高,并构建了各阶段的回归方程。基于反映市场价值和潜在产量变化的动态经济允许损害水平,得到大豆出苗期—4叶期、4叶期—初花期、初花期—初荚期和初荚期—鼓粒期阶段的平均蚜量阈值分别为79、227、323和460头/株;依据线性相关性转换得到更利于实际应用的阈值指标——有蚜株率和卷叶株率,如果提前3 d进行防治,则出苗期—4叶期阶段的有蚜株率阈值为17.88%,4叶期—初花期、初花期—初荚期和初荚期—鼓粒期阶段的卷叶株率阈值分别为4.78%、7.88%和12.59%。表明大豆蚜阶梯式的阶段特异性经济阈值随大豆生育期的推进而放宽;且提前3 d的准备时间便于种植者进行早期决策,从而有针对性地选择防治大豆蚜的作物生育期。 相似文献
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Studies were conducted to examine interactions between esfenvalerate and Bacillus thuringiensis Berl. in their effects on feeding behavior of larvae of Plutella xylostella L. and Leptinotarsa decemlineata Say. Droplets containing esfenvalerate, B. thuringiensis, the two in combination, and water controls were individually applied to leaf disks. Third-instar P. xylostella larvae were allowed to feed for 24 h on cabbage disks and third-instar L. decemlineata larvae were allowed to feed for approximately 18 h on potato leaf disks. For each insect species and each treatment, the proportion of leaf area removed during the feeding period was regressed on the proportion of droplets removed during that period to test for avoidance of droplet residues. No significant differences were found between treatments in these regressions for L. decemlineata. In contrast, B. thuringiensis, either alone or in combination with esfenvalerate, significantly affected the relationship of leaf and droplet consumption for P. xylostella. No evidence of individual droplet avoidance, i.e. a consistently greater proportion of leaf than droplets consumed, was found for any of the treatments. Proportions of leaf consumed and proportions of droplets consumed were compared among treatments to test for effects on feeding rate. B. thuringiensis significantly reduced feeding rate, both alone and in combination with esfenvalerate for P. xylostella and alone for L. decemlineata. We found no statistically significant differences in feeding rate due to esfenvalerate. The species studied can be expected to consume the same amount of B. thuringiensis whether it is mixed with esfenvalerate or not, whereas esfenvalerate dose by ingestion would be reduced if it were mixed with B. thuringiensis. 相似文献
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连作晚稻三化螟为害损失与防治指标研究 总被引：7，自引：1，他引：7
三化螟幼虫在晚梗稻分蘖、圆秆、孕穗、破口期均能侵入,所形成的为害株数、为害类型和幼虫存活率与生育期有密切关系,为害丛、株增长呈S型曲线。分蘖期、孕穗—破口期引起丛、株为害率和损失率与卵块密度显著相关,每个卵块损失稻谷分别为59.11±2.99g、74.58±3.31g。考种结果表明,产量损失的主要原因是有效穗减少。在现有生产条件下,三化螟经济允许卵块密度为:分蘖期130—150块/666.7m~2,孕穗—破口期100—120块/666.7m~2;防治指标:分蘖期100—110块/666.7m~2,为害团50—60个/666.7m~2,丛为害率2.0％—3.0％,株为害率1.0％—1.5％。 相似文献
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Franck E. Dayan Stephen O. Duke John D. Weete H. Gary Hancock 《Pest management science》1997,51(1):65-73
Post-emergence application of carfentrazone-ethyl at rates as low as 2·2 g ha-1 caused greater leaf injury and growth reduction in ivyleaf morningglory (Ipomoea hederacea) and velvetleaf (Abutilon theophrasti) than in soybean (Glycine max). The herbicide was more rapidly metabolized in the crop than in the weed species, with 26·7, 54·3 and 60·6% of the parent compound remaining in soybean, ivyleaf morningglory and velvetleaf, respectively, 24 h after exposure. The free acid metabolite, carfentrazone, was present in all species and accounted for 21·2–27·4% of the total radioactivity. Unknown metabolites (Rf 0 and 0·22) were four to five times more abundant in soybean than in the weed species. Carfentrazone-ethyl induced more leakage from leaf discs from the weeds than those from soybean and the degree of injury correlated with the amount of protoporphyrin IX (Proto IX) present in the treated tissues. Both carfentrazone-ethyl and carfentrazone were potent inhibitors of protoporphyrinogen oxidase (Protox). Therefore, the selectivity of this herbicide may, at least in part, be attributed to the lower accumulation of Proto IX in soybean than in the weeds, probably because of the ability of soybean to metabolize more carfentrazone into unknown metabolites than the weeds. © 1997 SCI. 相似文献
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The incidence levels of moths and larvae of Etiella zinckenella were studied in the reproductive stage of soybean at eight farmers' field sites. A positive relationship was found between moths, caught by sweeping during flowering and pod-formation, and seed damage. Hence, rough predictions of damage can be made based on moth catches. Damage incidence was recorded in unsprayed plots and in plots sprayed with deltamethrin during flowering and pod-formation. Spraying did not affect the densities of moths and larvae or damage to pods and seeds. Larvae of H. armigera, Spodoptera litura and Plusiinae were not affected by spraying, but the pod-sucking bug Riptorus linearis, and two groups of predators, spiders and coccinellids, were reduced. 相似文献
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The numbers and species of phytoparasitic nematodes on soybean were studied over several years in Croatia, especially in the regions of Slavonija and Baranja. 19 phytoparasitic species were found, and of these Pratylenchus spp. predominated. These nematodes were found in mixed populations and their numbers were, at times, enormous. The average number per 100 ml of soil was about 100 individuals, with a maximum of 3348. The relationship between the number of nematodes and yield of soybean was calculated by a single regression equation. The soybean cultivars Sava and OS-88 apparently possess tolerance to relatively high numbers of Pratylenchus spp. in the rhizosphere. 相似文献
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Evaluation of action thresholds for chronic rice insect pests in the Philippines. III. Leaffolders 总被引：1，自引：0，他引：1
J. A. Litsinger J. P. Bandong B. L. Canapi C. G. Dela Cruz P. C. Pantua A. L. Alviola 《国际虫害防治杂志》2013,59(3):181-194
Abstract Action thresholds (AT) as insecticide application decision tools were developed and tested against rice leaffolders Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae) in four sites and 68 crops over a 13-year period in the Philippines. Leaffolder damage levels were generally low with a mean over all sites and crops of 2 – 3% damaged leaves (DL) and 6 – 9% in a given site as a per-crop average based on weekly samplings, with highest incidence per field on a given sampling date of 48%DL. The damage incidence over a typical crop cycle formed a bell-shaped curve with maximum numbers in the late reproductive and early ripening stages. Continuous population buildup over the planting cycle did not occur in any one site over the season, thus a strategy of monitoring earlier planted fields to forewarn against impending economic damage had no basis. ATs were based on different levels of percentage DL, number of larvae per hill (L), and density of flushed moths. Collectively ATs were surpassed in 1, 12, and 4% of fields in each of the three main growth stages. A scoring system was based on benchmark criteria including both leaffolder damage and yield loss. The 15%DL threshold performed best in all growth stages, only equaled by 1L in the vegetative stage, scoring 93 – 99% correct decisions in each of the growth stages. Flushed moths produced the most false positive decisions and the lowest performance scores. The best insecticide response gave only a disappointing 53% control and therefore was a significant weakness in using AT technology. BPMC, endosulfan, and monocrotophos performed the best and azinphos-ethyl and Bt the least. Sites with the highest densities had the most rapid rise in damage levels, thus requiring more frequent monitoring. Low leaffolder damage levels were most likely due to the activity of natural enemies. Given the ability of high tillering varieties to compensate from pest damage, farmers would be better off embracing integrated crop management as a preventative measure to bolster inherent tolerance levels combined with crop monitoring based on historical population levels. In sites with a record of high damage levels, monitoring should start 4 weeks after transplanting (WT) on a weekly basis and more risk averse farmers may increase the interval to twice a week during flag leaf stage. In sites with lower observed levels, monitoring can begin 6 WT on a weekly basis and continue through the flag leaf stage. Significant yield increases were recorded with the best AT characters despite evidence of modern rices to tolerate high damage levels. Reasons for this apparent paradox are discussed. 相似文献