共查询到18条相似文献，搜索用时 140 毫秒
1.
2.
棉田及其边缘杂草对天敌的影响 总被引：8，自引：2，他引：8
1998～2000年间 ,作者通过网捕调查了新疆棉田和边缘杂草中天敌种类和数量 ,结果表明 :在棉田边缘杂草和棉田中主要天敌有多异长足瓢虫(Hippodamia variegata)、孪斑瓢虫 (Coccinella geminopunctata)、十一星瓢虫 (Coccinel laundecimpunctata)、中华草蛉 (Chrysopasinica)、大草蛉 (C .septempuctata)和丽草蛉 (C .formasa)。在通常情况下 ,棉田天敌数量大于杂草中 ,杂草群落为天敌提供多样的栖息地和食物源 ,间接或直接地影响了天敌在棉田和杂草群落中空间分布。 相似文献
3.
为实现我国非重要的检疫性杂草——苍耳属Xanthium杂草快速高效的分子鉴定,利用Illumina二代测序平台对白苍耳X.albinum、意大利苍耳X.italicum、直刺苍耳X.ripicola、刺苍耳X.spinosum、柱果苍耳X.cylindricum、宾州苍耳X.pennsylvanicum、蝟实苍耳X.echinatum、苍耳X.sibiricum和北美苍耳X.strumarium共9种苍耳属杂草进行转录组测序,获得的unigene序列数分别为103 362、93 506、87 452、83 822、70 994、66 397、57 598、57 164和57 134个。利用生物信息分析方法对9种苍耳属杂草转录组进行简单重复序列（simple sequence repeat,SSR）和物种间的特异性序列预测和筛选。经过PCR试验验证,筛选获得了可以有效鉴定上述9种杂草的6对SSR引物和13对特异性引物,提高了苍耳属杂草鉴定的准确率。 相似文献
4.
5.
为明确草地贪夜蛾Spodoptera frugiperda对主要杂草的取食适应性，以牛筋草Eleusin indica、马唐Digitaria sanguinalis、狗尾草Setaria viridis、香附子Cyperus rotundus及饭包草Commelina benghalensis为寄主，采用室内饲养观察法和分光光度法测定草地贪夜蛾取食这5种杂草寄主后的生长发育情况及消化酶的活性。结果显示：草地贪夜蛾在5种杂草寄主上均能够完成生活史。以马唐、牛筋草为食的草地贪夜蛾1~3龄幼虫的存活率最高，分别为95.83%和93.33%；以香附子为食时其蛹的存活率最低，为79.80%，且以香附子为食时草地贪夜蛾各阶段的发育历期显著长于以马唐、牛筋草及狗尾草为食时；以马唐为食时草地贪夜蛾的幼虫体重、蛹重、产卵量以及中肠蛋白质浓度均显著高于以其它杂草为食时，而以香附子为食时草地贪夜蛾幼虫的中肠脂肪酶和淀粉酶活性最高，分别为39.93 μg/mL和0.117 μg/mL。表明取食不同杂草寄主，对草地贪夜蛾的生长发育及生理指标有显著影响，其中草地贪夜蛾对马唐具有较高的取食适应性。 相似文献
6.
为明确小麦Triticum aestivum田新型除草剂砜吡草唑与嗪草酮复配应用于大豆Glycine max-玉米Zea mays带状复合种植田的可行性,在温室内采用Gowing法测定砜吡草唑与嗪草酮复配的联合作用类型,并通过盆栽法测定两者复配制剂80%砜吡·嗪草酮水分散粒剂（water dispersiblegranule,WDG）的杂草防除谱以及对大豆和玉米的安全性。结果显示,砜吡草唑与嗪草酮复配防除禾本科杂草马唐Digitaria sanguinalis和稗Echinochloa oryzicola的联合作用类型属于增效作用;对阔叶杂草苘麻Abutilon theophrasti和龙葵Solanum nigrum的联合作用类型属于加成作用。80%砜吡·嗪草酮WDG对6种禾本科杂草马唐、稗、牛筋草Eleusine indica、狗尾草Setaira viridis、虎尾草Chloris virgata、大狗尾草Setaira faberii和4种阔叶杂草马齿苋Portulaca oleracea、青葙Celosia argentea、铁苋菜Acalypha australis、反枝苋Amaranthus retroflexus的防除效果均很好,其GR50在6.1~21.6 g (a.i.)/hm2之间,GR90在16.3~50.5 g (a.i.)/hm2之间,对苘麻和龙葵的防除效果略差,其GR50分别为53.3 g (a.i.)/hm2和25.4 g (a.i.)/hm2,GR90分别为282.1 g (a.i.)/hm2和96.7 g (a.i.)/hm2,低于其田间推荐剂量300~360 g (a.i.)/hm2,且该药剂对玉米和大豆的安全性都很高,在玉米与马唐、稗、牛筋草、马齿苋、青葙及铁苋菜这6种杂草之间的选择性指数均大于13.6,在大豆与这6种杂草之间的选择性指数均远大于28.5。表明砜吡草唑完全可与嗪草酮复配应用于大豆-玉米带状复合种植田的杂草防除。 相似文献
7.
8.
为明确环磺酮在我国玉米田的应用技术和前景,采用温室盆栽法测定环磺酮的杀草谱和对常见杂草的除草活性以及对不同玉米品种的安全性,并通过田间药效试验验证其应用效果。结果表明,在100 g (a.i.)/hm2田间推荐剂量下进行茎叶处理时,环磺酮可以有效防除玉米田常见禾本科、莎草科和阔叶杂草,其中对反枝苋Amaranthus retroflexus、鳢肠Eclipta prostrata的活性较高,鲜重抑制率可达90%以上;对6种常见玉米田杂草稗Echinochloa crus-galli、马唐Digitaria sanguinalis、圆叶牵牛Ipomoea purpurea、反枝苋、碎米莎草Cyperus iria和青葙Celosia argentea的生长抑制中量GR50分别为8.44、17.16、9.37、8.68、9.40和32.51 g (a.i.)/hm2,在供试剂量下环磺酮的除草活性均高于对照药剂硝磺草酮;田间推荐剂量下环磺酮对除黑糯301品种以外的11个玉米品种均较为安全,提高到2倍推荐剂量时,对不同玉米品种的生长抑制均增强;环磺酮对郑单958、珍珠糯8号、苏科甜1506和中糯2号4个玉米品种以及稗、马唐、圆叶牵牛、反枝苋、碎米莎草和青葙6种杂草之间均具有较好的选择性,选择性指数为10.40~29.14。田间药效试验表明,126 g (a.i.)/hm2环磺酮处理茎叶后第28天,对玉米田杂草稗、马唐、狗尾草Setaria viridis、香附子Cyperus rotundus、圆叶牵牛、空心莲子草Alternanthera philoxeroides的总株防效为86.51%,鲜重防效为87.81%,且对供试玉米品种彩甜糯102安全。 相似文献
9.
朱海霞 《干旱地区农业研究》2024,(1):237-241
以青海省西宁市大通县鹞子沟自然发病的大刺儿菜叶片中分离出的附球属真菌DT-014为研究对象，通过发酵喷雾法接种测定其对4种盆栽杂草猪秧秧（Galium spurium L.）、藜（Chenopodium album L.）、冬葵（Malva verticillate L. var. crispa）、密花香薷（Elsholtzia densa Benth.）的致病性和5种作物蚕豆（Vicia faba L.）、豌豆（Pisum sativum L.）、青稞（Hordeum vulgare L.）、小麦（Triticum aestivum L.）、油菜（Brassica napus L.）的安全性，并通过单因素试验，以菌落直径和其孢子悬浮液OD600值为测量标准，探究菌株DT-014的最适生长培养基、碳源、氮源、固态发酵基质。结果表明，DT-014对藜（C. album）和猪秧秧（G. spurium）致病力较强，其次为密花香薷（E. densa），对冬葵（M. crispa）致病力最低。DT-014对于小麦（T. aestivum）、蚕豆（P. sativum）、青稞（H. vulgare）、豌豆（P. sativum）相对安全，对油菜（B. napus）有轻微影响。DT-014的最适培养基为蛋白胨培养基，最适碳源为葡萄糖，最适氮源为酵母膏，最适固态发酵基质为大豆粉。 相似文献
10.
喹草酮与莠去津复配防除杂草效果及对高粱的安全性 总被引：1，自引：1，他引：1
为明确对羟基丙酮酸双氧化酶抑制剂类新型除草剂喹草酮应用于高粱田的可行性，于2018-2019年在温室和田间测定喹草酮与莠去津复配的除草效果及对高粱的安全性。温室试验结果表明，喹草酮与莠去津复配对狗尾草Setaria viridis和苘麻Abutilon theophrasti均有很好的防除效果，两者按有效成分用量比1：4~1：7配比对狗尾草的GR50在134.40~168.92 g （a.i.）/hm2之间，明显好于喹草酮和莠去津单独施用时的GR50，分别为150.53g （a.i.）/hm2和589.30g （a.i.）/hm2；两者复配对狗尾草的共毒系数在234.80~311.03之间，远大于120.00，显示出明显的增效作用；对苘麻的共毒系数在140.16~168.38之间，也表现出增效作用；对马唐Digitaria sanguinalis也有较好的防除效果；喹草酮与莠去津按有效成分用量比1：5复配的制剂在最高用量3 600g （a.i.）/hm2处理下，3个高粱品种生长均正常，且对高粱和杂草之间的选择性指数远大于6.59，对高粱的安全性高。田间试验结果表明，喹草酮与莠去津复配应用于高粱田对高粱安全，且对田间杂草野稷Panicum ruderale、虎尾草Rabdosia eriocalys、稗Echinochloa crus-galli、反枝苋Amaranthus retroflexus和藜Chenopodium album等均有极好的防除效果，2018-2019年对高粱田杂草的总株防效分别为94.2%和92.8%，鲜重防效分别为95.6%和94.2%，明显高于药剂对照50%异甲·莠去津悬浮剂土壤处理和37%二氯·莠去津悬浮剂茎叶处理的防除效果。表明喹草酮与莠去津复配应用于高粱田防除杂草效果良好。 相似文献
11.
为明确小麦田不同杂草群落及防除时间对小麦产量的影响,于2013—2015连续两年在山东省聊城市高唐县小麦田中设无草对照区、禾本科杂草区、阔叶杂草区以及混合杂草自然发生区4种不同杂草群落以及不同的杂草防除时间,测定在不同条件下小麦产量及各项产量构成指标的情况。结果表明,阔叶杂草对小麦产量的影响大于禾本科杂草,冬小麦田杂草的最佳防除时间为4月1日之前,在此期间除草对小麦产量影响均不大,但之后防除或不除草会造成小麦严重减产甚至绝产,2014年4月15日除草可造成在阔叶杂草区和杂草混合生长区的小麦减产30.5%和32.6%,不除草可造成在禾本科杂草区、阔叶杂草区和杂草混生区的小麦减产8.6%、91.4%和94.3%,2015年趋势和2014年一致。从构成小麦产量的3个指标来看,杂草危害主要影响小麦的总穗数,其次为穗粒数,对千粒重影响最小。 相似文献
12.
M D Amador-Ramírez 《Weed Research》2002,42(3):203-209
Summary Field experiments were conducted from 1991 to 1993 to determine the critical period of weed control in chilli pepper. The maximum weed-infested period ranged between 0.7 and 3.2 weeks after transplanting (WAT) at a 5% yield loss level. To prevent losses in total and marketable yields, weeds should be removed 2.1 or 0.9 WAT respectively. The end of the critical period decreased as the predetermined yield loss level increased from 2.5% to 10%. The minimum weed-free period ranged between 6.7 and 15.3 WAT at a 5% yield loss level depending on crop yield category. The chilli pepper crop required an average of 12.2 weeks of weed-free maintenance to avoid losses above 5%. Using a 5% yield loss level, the duration of the critical period of weed control was 14 weeks in 1991 and 11.2 weeks in 1993, but was shortened to 5.1 weeks in 1992. The results suggest that weeds must be controlled during the first half of the crop's growing season in order to prevent yield losses. 相似文献
13.
The importance of the position of weeds with respect to crop rows in the determination of crop yield-weed density relationships and the usefulness of relative cover (RC) of the weeds as an explanatory variable were studied in soyabean [Glycine max (L.) Merrill] competing with two summer weeds with contrasting canopy structure (Xanthium strumarium L. ssp. italicum and Echinochloa crus-galli L.). The position of the weeds was of little importance in the relationship between yield loss and weed density. This information is important because published experiments have used different types of weed distribution (e.g. evenly distributed or sown in rows). For both weed species it was possible to obtain a single relationship between yield loss and RC for measurements made from 30 days after crop emergence to soyabean canopy closure. The competitive effect of the weeds appeared to be strictly related to RC, indicating that for weeds growing taller than the crop the main competitive factor may be the shading caused by the leaves of the weeds situated above the crop canopy. 相似文献
14.
为了明确湖南省烟田杂草种群与分布,采用对角线五点取样法在全省烟田进行了系统调查。结果表明,烟田杂草共有30科77种,其中禾本科杂草占比14.29%,阔叶杂草占比81.82%,莎草科杂草占比3.89%;一年生杂草占比75.32%,多年生杂草占比24.68%。相对多度大于3%的杂草有铁苋菜、酸模叶蓼、稗、碎米荠、马唐、繁缕、喜旱莲子草、看麦娘、通泉草、鸭跖草、水苦荬等11种,其中铁苋菜、酸模叶蓼、稗为湖南省烟田优势杂草种群,碎米荠、马唐、繁缕、喜旱莲子草、看麦娘、通泉草、鸭跖草、水苦荬为湖南省烟田区域性优势杂草种群。湖南省烟田杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法,主要使用的化学除草剂是精异丙甲草胺和砜嘧磺隆。本研究结果表明,湖南省烟田杂草存在区域性差异,应因地制宜制定合适的化学防治方案。 相似文献
15.
A sugarbeet field experiment was conducted in 1999 and 2000 to measure beet yield where Sinapis arvensis or Lolium perenne were growing in the crop row at 2, 4 or 8 cm from the beet plants. The weeds were removed by cutting once in the growing season in either late May, mid‐June or early July. The number of neighbouring beet plants to every target beet plant was recorded. Projected leaf cover of a subset of the data with non‐cut weeds was analysed by using image analysis to investigate whether this could be used to predict beet yield loss early in the growing season. Increasing the distance between beet and weed from 2 to 8 cm increased the beet yield significantly by an average of 20%, regardless of weed species. The dry weight of non‐cut and re‐growing weeds at harvest time decreased when cutting was postponed to the period between mid‐June and early July. The number of neighbours described a sigmoidal yield decline of the single beet plants. Results from image analysis showed that approximately 33 g of beet yield was lost in October/November for each per cent relative projected leaf cover of the weeds in May, despite variation in growing conditions. The results are discussed in relation to potentials for robotic in‐row weed control. 相似文献
16.
17.
A simple model of crop loss by weed competition from early observations on relative leaf area of the weeds 总被引：8，自引：1，他引：8
A new simple empirical model for early prediction of crop losses by weed competition was introduced. This model relates yield loss to relative leaf area of the weeds shortly after crop emergence using the relative damage coefficient q as the single model parameter. The model is derived from the hyperbolic yield density relationship and therefore accounts for the effects of weed density. It is shown that the model also accounts for the effect of different relative times of weed emergence. A strong advantage of the approach is that it can be used when weeds emerge in separate flushes. The regression model described experimental data on sugar-beet – lambsquarters (Beta vulgaris L. –Chenopodium album L.) and maize-barnyard grass (Zea mays L. –Echinochloa crus-galli L.) competition precisely. The model describes a single relationship between crop yield loss and relative leaf area of the weeds over a wide range of weed densities and relative times of weed emergence. Possibilities for scientific and practical application of the model are discussed. 相似文献
18.
近年我国农田杂草防控中的突出问题与治理对策 总被引：7，自引：0，他引：7
我国田园杂草有1 400多种,严重危害的130余种,恶性杂草37种。我国杂草发生面积约9 246.7万hm2次,防治面积1.04亿hm2次,挽回粮食损失2 699万t,每年主粮作物仍有近300万t产量损失。杂草防控中的突出问题是:杂草群落演替,难治杂草种群增加;除草剂单一使用,杂草抗药性发展迅速;除草剂对作物药害频发,影响种植结构调整;新除草剂创制能力不足,难以满足不同作物田除草需求;农村劳动力短缺,杂草防控更依赖于化学防治。解决上述问题,应实施以下对策:加强杂草发生危害的监测预警,科学轮换使用除草剂,推广除草剂减量与替代技术,加快新除草剂研制及推广应用,加速耐除草剂作物商业化进程,推进统防统治及农民培训。 相似文献