精异丙甲草胺苗前封闭处理对大豆苗期生长及其生理生化指标的影响

为明确精异丙甲草胺苗前封闭处理对大豆苗期生长及其生理生化指标的影响,通过室内试验,测定大豆幼苗在不同浓度精异丙甲草胺处理后28 d的相关农艺性状及各生理生化指标。结果表明,1 224 g(a.i.)/hm~2精异丙甲草胺处理对大豆生长的促进效果最好,可使植株显著增高27.06%,根显著增长10.53%,茎叶鲜重显著增加35.62%、干重显著增加33.33%,根系鲜重显著增加70.45%。大豆叶片叶绿素含量随药剂浓度的增加而降低,但在383~1 530 g(a.i.)/hm~2内与对照无显著差异;各药剂处理浓度均可增强大豆叶片过氧化物酶活性,其中3 060 g(a.i.)/hm~2处理最高,比对照显著增强32.10%;在765、1 224 g(a.i.)/hm~2浓度下均可增强过氧化氢酶和超氧化物歧化酶的活性,1 224 g(a.i.)/hm~2处理时分别比对照提高20.72%和2.88%。表明精异丙甲草胺苗前封闭处理在一定使用浓度范围内对大豆苗期植株生长有显著促进作用,对其叶绿素合成无显著影响,可有效提高抗氧化酶活性,是一种对大豆田环境友好且安全性高的除草剂。     

赤霉素缓解Mn~(2+)对草甘膦拮抗效应的研究

为探索能够减轻或消除Mn2+对草甘膦拮抗效应的方法,以高羊茅为试材,将赤霉素(GA3)与草甘膦和硫酸锰(Mn2+质量分数为0.1%)混用,研究了赤霉素对Mn2+降低草甘膦药效的缓解作用。结果表明:赤霉素+草甘膦+硫酸锰处理组高羊茅比同剂量草甘膦+硫酸锰处理组叶色更黄,萎蔫更严重,与同剂量草甘膦单剂处理组比较接近,其中加入50 mg/L赤霉素处理组缓解草甘膦拮抗效应的效果最好。赤霉素+草甘膦+硫酸锰处理组高羊茅的干、鲜重及叶绿素含量均低于草甘膦+硫酸锰处理组,而丙二醛和莽草酸含量均明显高于草甘膦+硫酸锰处理组。处理后第6天,赤霉素+草甘膦+硫酸锰组莽草酸含量分别比草甘膦+硫酸锰组增加了49.8%(加入50 mg/L赤霉素)和28.8%(加入30 mg/L赤霉素),差异显著;处理后第2天,赤霉素+草甘膦+硫酸锰组丙二醛含量分别比草甘膦+硫酸锰组增加了54.1%(加入50 mg/L赤霉素)和52.9%(加入30 mg/L赤霉素),差异显著。研究表明,将赤霉素与锰肥和草甘膦混合喷施,将有可能在一定程度上缓解Mn2+对草甘膦的拮抗效应,保证草甘膦的除草效果。     

三氯吡氧乙酸、氯氟吡氧乙酸、2甲4氯和草甘膦对葎草的防除活性比较

本文通过温室整株生物测定法比较研究了三氯吡氧乙酸、氯氟吡氧乙酸、2甲4氯钠和草甘膦异丙胺盐4种常用于水稻、小麦种植区防控大龄阔叶杂草的茎叶处理除草剂对6～8叶期葎草Humulus scandens的防除活性。结果表明,在210 g/hm~2剂量下,三氯吡氧乙酸和氯氟吡氧乙酸可完全杀灭供试葎草植株,在420 g/hm~2剂量下,2甲4氯钠对葎草的鲜重抑制率达到95.25%,而草甘膦异丙胺盐840 g/hm~2剂量处理对葎草的鲜重抑制率仍不足80%。进一步通过Logistic曲线模型分析除草剂对葎草鲜重抑制率达到50%和90%的剂量(GR_(50)和GR_(90)剂量)发现,三氯吡氧乙酸、氯氟吡氧乙酸、2甲4氯钠和草甘膦异丙胺盐相应的GR_(50)分别为58.74、76.96、182.52和272.82 g/hm~2; GR_(90)分别为143.97、202.83、678.27和2 980.11 g/hm~2。结论:对于水稻、小麦种植区葎草危害,优先推荐使用三氯吡氧乙酸防除,其次是氯氟吡氧乙酸;使用2甲4氯防控效果不够理想,使用草甘膦无法有效控制。     

草甘膦应用于耐除草剂大豆玉米带状复合种植田的效果

以草甘膦钾盐为供试除草剂,设计其不同用量以及与不同助剂配套的处理,以当地常规除草剂为药剂对照,在内蒙古大豆玉米带状复合种植田开展了化学除草试验,调查草甘膦不同处理对试验田种植的耐除草剂转基因作物的安全性,以及对田间主要杂草的防效。结果表明,各施药处理以对照药剂硝·烟·莠去津+松·喹·氟磺胺对作物的药害最大,药后7 d在大豆、玉米上的药害分别达3级、1级;草甘膦处理对作物的药害较轻,低剂量处理区未见药害,高剂量处理区药后7 d在大豆上产生2级药害,药后15 d降至1级,药后30 d药害消失,作物恢复正常生长。草甘膦钾盐低剂量+甲基化植物油助剂处理对田间主要杂草藜、反枝苋、稗的整体防效最高,药后45 d的株防效为94.12%～95.40%,鲜重防效为94.71%～98.83%,相应处理区玉米、大豆的产量也较高。     

草甘膦对甘蓝类蔬菜的药害

1985、1988年于春番茄收获后,每亩用10％草甘膦水剂1—1.5公斤喷雾防除田间杂草,施药后30—60天移栽甘蓝、花椰菜、矮白菜和播种小白菜等,发现甘蓝、花椰菜活棵后即表现药害,轻者主根呈黑褐色,须根腐烂,主根齐土面部分缢缩,其上有部分长出不定根,植株僵化不发;重者主根腐烂,叶片呈水渍状烂斑,3—5天植株枯死。在同一个蔬菜品种中,药害程度因叶色深浅而异,浅色型重于深色型。发生药害的植株,立即拔起用水漂洗,再移栽到未用药的田块,仍能恢复正常生长。     

结球甘蓝抗根肿病SSR分子连锁图谱的构建

结球甘蓝(Brassica oleracea L.var.capitata)简称甘蓝,是我国重要的蔬菜作物之一.甘蓝根肿病是由芸苔根肿菌(Plamodiophora brassicae Woron.)侵染引起的一种世界性真菌病害.近年来,该病在我国的发病面积急剧增加,造成甘蓝产量和品质大幅度降低,选育抗病品种成为防治根肿病的重要途径之一.     

10种除草剂及组合对芨芨草的防效评价

为筛选出对芨芨草具有高效防除作用的除草剂品种及组合,本研究采用茎叶喷雾法分别在芨芨草开花期和平茬(成株芨芨草离地面15 cm刈割)后第3天施药,测定了10种常用除草剂品种和6个除草剂组合对芨芨草的防除效果,获得了"花期茎叶喷施除草剂"和"平茬+喷施除草剂方式"清除芨芨草技术。1)开花期:18%草铵膦AS在有效剂量(下同)405 g/hm~2时,药后7 d见效,30 d鲜重防效达100%;41%草甘膦异丙胺盐AS剂量为922.5 g/hm~2时,药后5 d见效,30 d鲜重防效达87.18%;24%烯草酮EC剂量为216 g/hm~2时,药后15 d见效,30 d鲜重防效达77.03%;18%草铵膦AS 180 g/hm~2+10.8%高效氟吡甲禾灵EC 37.8 g/hm~2处理,药后5 d见效,30 d鲜重防效达91.30%。2)平茬后:18%草铵膦AS、41%草甘膦异丙胺盐AS均药后5 d见效,30 d鲜重防效均大于87%;30%苯唑草酮SC剂量为22.5 g/hm~2时,药后5 d见效,30 d鲜重防效达85.97%;24%烯草酮EC剂量为144 g/hm~2时,药后7 d见效,30 d鲜重防效达88.21%;15.8%精喹禾灵EC剂量135 g/hm~2时,药后7 d见效,30 d鲜重防效达85.26%;12.5%烯禾啶EC 112.5 g/hm~2+15.8%精喹禾灵EC 15.8 g/hm~2处理,药后5 d见效,30 d鲜重防效达97.97%。     

除草剂防除果园杂草的初步研究

据在果园两年试验结果,草甘膦和赛克津防除艰果园阔叶和窄叶杂草效果好。草甘膦适于在无间作果园使用,赛克津还适于在间作马铃薯、番茄、大豆、豌豆、芦笋的果园使用。使用剂量:草甘膦100～200克/亩,赛克津24～48克/亩。百草敌和酚硫杀对阔叶杂草有较好防除效果,适于在间作禾本科作物的果园使用。使用剂量:百草敌9.6～12.8克/亩,酚硫杀60～80克/亩。施药方法为定向喷射,避免药液接触果树。     

转基因耐草甘膦大豆对豆田节肢动物群落多样性的影响

在田间试验条件下,采用直接观察法,通过对多样性指数、优势集中性指数、均匀性指数、物种数的分析比较,研究转基因耐草甘膦大豆对豆田节肢动物群落多样性的影响。结果显示,大豆生长期转基因耐草甘膦大豆和受体的节肢动物多样性指数、均匀性指数、物种数均显著低于当地常规品种,优势集中性指数显著高于当地常规品种,但转基因抗草甘膦大豆与对照受体间各指标无显著性差异,说明转基因耐草甘膦大豆对豆田节肢动物群落无明显影响。     

日本十字花科作物芜菁花叶病毒株系

本文根据芜菁花叶病毒(TuMV)对选择的一套日本萝卜(Raphanus sativus L.)、卷心莱(Brassica oleracea subsp capitata L.)和白菜(B.campestris subsp.pekinensis)鉴别品种反应来区分从日本十字花科作物上分离的47个 TuMV 株系,将它们分为9个株系组.其中除少数高抗品种外能系统感染所有供试品种的 A.B 株系组可以用作培育高抗 TuMV 的十字花科作物品种的接种源.还发现了不同于普通和甘蓝株系组的 TuMV 甘蓝温和株系.     

Effects of aqueous extracts and decomposition of Mikania micrantha H.B.K. debris on selected agronomic crops

Laboratory and greenhouse experiments were conducted to determine the effects of aqueous extract and the debris of Mile-a-Minute ( Mikania micrantha H.B.K.) on the germination and growth of four test species, viz. tomato ( Lycopersicon esculentum Mill.), Chinese cabbage ( Brassica chinensis L.), corn ( Zea mays L.) and long bean ( Vigna sesquipedalis L.). Germination percentage, radicle length and fresh weight of two crops, Chinese cabbage and tomato, decreased progressively when plants were exposed to increasing concentrations (12.5, 25, 37.5 and 50 g L⁻¹) of aqueous extract of Mikania , but did not affect those of corn and long bean seedlings. The emergence of tomato and Chinese cabbage was greatly reduced when Mikania debris was incorporated into the soil, irrespective of the amount of debris and the decomposition period. In contrast, the emergence of corn and long bean seedlings was not affected. The application of fertilizer (NPK 15 : 15 : 15) enhanced the fresh weight of all seedlings tested as compared with those not supplied with the fertilizer. Four compounds were identified in the leaf extract of Mikania , viz. caffeic acid, p -hydroxybenzaldehyde, resorcinol and vanillic acid.     

玉米田两种阔叶杂草藜及苍耳对草甘膦的敏感性测定

苍耳Xanthium strumarium和藜Chenopodium album是常见的两种阔叶杂草,其在玉米田发生严重,影响了玉米的生长和产量。本文利用整株生物测定法对我国东北及黄淮海玉米产区采集到的苍耳及藜种群对草甘膦的敏感性进行了测定。种子室内培养至5~6叶期,喷施草甘膦后14 d称量鲜重,计算抑制杂草种群50%个体生长的草甘膦剂量(GR 50)。草甘膦对10个苍耳种群GR 50在54.87~249.75 g/hm^2,平均值为(111.53±20.02)g/hm^2,均低于450 g/hm^2(1/2倍推荐剂量),表明10个苍耳种群均对草甘膦敏感;草甘膦对33个藜种群GR 50范围在97.05~920.86 g/hm^2,平均值为(313.88±24.70)g/hm^2,93%的种群GR 50低于450 g/hm^2,表明绝大多数藜种群对草甘膦比较敏感,仅发现一个藜种群GR 50大于900 g/hm^2(田间推荐剂量),表明其对草甘膦具有一定耐受性。     

Sulcotrione soil persistence and mobility in summer maize and winter wheat crops

Sulcotrione soil persistence in spring maize ( Zea mays L.) crops grown on a sandy loam soil was greater at pH 5·5 and 6·0 (soil half-life T _1/2≈58 days) than at pH 7·1 ( T _1/2 = 44 days). Sulcotrione was also applied as recommended on a summer maize crop at the five- to six-leaf growth stage, grown on a sandy loam soil. Sulcotrione soil half-life was 44 days, and the herbicide remained mainly in the 0- to 5-cm surface soil layer during the cropping period, in spite of the high water solubility and the heavy rains at the end of August; lower sulcotrione concentrations (10–18% of the total during the 2-month period after sulcotrione application) were detected in the 5- to 10-cm surface soil layer. The herbicide was applied pre-emergence to winter wheat ( Triticum aestivum L.) at four sites that differed in their soil texture and composition: loamy sand, sandy loam, loam and clay loam. Persistence was greater in the soils containing more organic matter. In soils having similar organic matter contents, persistence was lower in the soil containing more sand relative to loam and clay. During the winter crops, sulcotrione moved down to the 10- to 15-cm soil layer, in spite of the fact that the rains were lower in winter than in summer. Sulcotrione most generally was not detected in the 15–20 cm soil layer of the maize and winter wheat crops.     

Biological Control of Black Rot (Xanthomonas Campestris Pv. campestris) of Brassicas with an Antagonistic Strain of Bacillus Subtilis in Zimbabwe

Biological control efficiency of an antagonistic, endophytic strain of Bacillus subtilis (strain BB) was evaluated against three strains of the black rot pathogen, Xanthomonas campestris pv. campestris (Xcc), in four Brassica crops (cabbage, cauliflower, rape and broccoli) grown during three consecutive growing seasons and on two soil types, in two different areas in Zimbabwe. Strain BB controlled the disease caused by strain Xcc B-147 in all Brassica crops during the dry and short rainy seasons. A similar effect was observed in cabbage using the strain Xcc 33908. Biological control was effective in broccoli, but not in cabbage and rape during the main rainy season in clay loam soil and limited biological control effect was still observed when these crops were grown in sandy loam soil. The endophytic colonisation of cabbage roots by strain BB was confirmed by immuno-blotting during the whole growing season. Biological control of black rot with strain BB is discussed in relation to its effect on Xcc strains, Brassica crops and to the effect of weather and soil conditions.     

防除宽叶酢浆草除草剂的室内生物活性评价

宽叶酢浆草Oxalis latifolia为入侵云南玉米地的进境检疫性鳞茎类杂草?为筛选防治该草的高效除草剂, 室内测定了8种除草剂对宽叶酢浆草的生物活性?结果表明, 用田间推荐剂量处理后30 d, 氯氟吡氧乙酸异辛酯(210 g/hm2)对宽叶酢浆草的鲜重抑制率超过90%, 硝磺草酮(202.50 g/hm2)?烟嘧磺隆(60 g/hm2)和砜嘧磺隆(25.13 g/hm2)处理的鲜重抑制率超过85%, 苯唑草酮(27 g/hm2)?莠去津(1 875 g/hm2)和2甲4氯钠(1 201.20 g/hm2)处理的鲜重抑制率分别为81.29%?76.36%和70.71%?1/4草甘膦推荐剂量(712.50 g/hm2)即可彻底杀死宽叶酢浆草?推荐剂量的草甘膦?氯氟吡氧乙酸异辛酯?砜嘧磺隆?烟嘧磺隆?硝磺草酮?莠去津?苯唑草酮和2甲4氯钠处理后30 d, 宽叶酢浆草的繁殖抑制率分别为100%?100%?98.17%?98.17%?90.87%?83.56%?81.74%和56.17%?其中氯氟吡氧乙酸异辛酯1/16推荐剂量(13.13 g/hm2)和草甘膦1/8推荐剂量(356.25 g/hm2)对宽叶酢浆草的繁殖抑制率仍超过90%?结果表明上述除草剂均可用于玉米地宽叶酢浆草的防除?草甘膦和氯氟吡氧乙酸异辛酯控制宽叶酢浆草生长和繁殖效果最优, 硝磺草酮?砜嘧磺隆和烟嘧磺隆也是优良的备选玉米宽叶酢浆草防治剂?     

[14C]Glyphosate transport in undisturbed topsoil columns

Although glyphosate (N‐(phosphonomethyl)glycine) is one of the most frequently used herbicides, few controlled transport experiments in undisturbed soils have been carried out to date. The aim of this work was to study the influence of the sorption coefficient, soil‐glyphosate contact time, pH, phosphorus concentration and colloid‐facilitated transport on the transport of [¹⁴C]glyphosate in undisturbed top‐soil columns (20 cm height × 20 cm diameter) of a sandy loam soil and a sandy soil. Batch sorption experiments showed strong Freundlich‐type sorption to both soil materials. The mobility of glyphosate in the soil columns was strongly governed by macropore flow. Consequently, amounts of glyphosate leached from the macroporous sandy loam soil were 50–150 times larger than from the sandy soil. Leaching rates from the sandy soil were not affected by soil‐glyphosate contact time, whereas a contact time of 96 h strongly reduced the leaching rates from the sandy loam soil. The role of pH and phosphorus concentration in solution was relatively unimportant with respect to total glyphosate leaching. The contribution of colloid‐facilitated transport was <1 to 27% for the sandy loam and <1 to 52% for the sandy soil, depending on soil treatment. The risk for glyphosate leaching from the top‐soils seems to be limited to conditions where pronounced macropore flow occurs shortly after application. © 2000 Society of Chemical Industry     

Leaf wall area and leaf area in cucumber,eggplant, sweet pepper and tomato grown in greenhouses in Switzerland

Various methods for the harmonization of the registration of crop protection products and dose adjustments in high growing crops have been discussed over many years. The leaf wall area (LWA) method has been known for some years already but it has received renewed attention due to a proposal by the European agrochemical manufacturing industry for harmonizing the dose expression in view of the new zonal registration system in the EU. The LWA method appears not only suitable for fruit trees and vineyards, but may also prove a simple and widely accepted method for dose adjustments in high growing vegetable crops particularly in greenhouses. This paper provides a dataset on leaf wall area and leaf area development for a selection of commercially grown cucumber, eggplant, sweet pepper and tomato varieties in Switzerland. Relationships between leaf wall area and leaf area have been established. A tentative product dose adjustment to growing vegetable crops in greenhouses is given for Switzerland. Biological efficacy trials will be required to validate the LWA method.     

乌鲁木齐地区甘蓝蚜发生规律初报

甘蓝蚜[Brevicoryne brassicae (Linné)]是烏魯木齐地区十字花科蔬菜上最主要的蚜虫。从9月下旬开始,在晚甘藍、晚苤藍及大白菜等蔬菜靠近地面的根、茎凹陷处,以及叶柄基部和叶片上产卵。蚜卵既可随寄主在菜窖里越冬;也可在菜株残体上露地越冬。露地越冬蚜卵,一般不能成为早春的有效蚜源,因其孵化率极低;孵化出来的少数干母,由于不能及时得到食料或因气候不适合,难以存活。越冬蚜卵于4月下旬孵化,5月中旬末产生有翅蚜,主要先在越冬寄生及冬蘿卜留种株上繁殖;到5月下旬至6月初,才陆續迁飞到春、夏十字花科蔬菜及春油菜上,大量繁殖和为害。7月下旬至8月初,晚甘藍与晚苤藍上的蚜虫便成为大白菜和冬蘿卜苗期的主要蚜源。甘藍蚜在烏魯木齐地区,无論是在菜窖里,或是在露地残株上,均不能以成蚜越冬。     

咪唑啉酮类除草剂对后茬作物安全性研究初报

1996～ 2 0 0 0年进行了咪唑啉酮类除草剂土壤残留对后茬作物影响的田间小区试验。结果表明 ,金豆 (imazamox,甲氧咪草烟 ) 40、6 0 g/ hm2 (在推荐剂量范围内。有效浓度 ,下同 ) ,施药后 12个月可以安全种植小麦、玉米和白瓜籽 ,2 4个月后可以安全种植油菜、甜菜、白菜、亚麻和马铃薯 ;金豆高剂量 (80、 12 0 g/ hm2 )对敏感作物有一定的药害。金普施特(imazethapyr/ imazamox) 50 g/ hm2 (推荐剂量 ) ,施药后 12个月可安全种植小麦、玉米 ,2 4个月可安全种植油菜、白瓜籽和马铃薯 ,不可种植甜菜、白菜和亚麻 ;倍量 (10 0 g/ hm2 )可使敏感作物严重受害。普施特 (imazethapyr) 75g/ hm2 (推荐剂量 ) ,施药后 12个月可安全种植小麦和玉米 ,2 4个月可安全种植白瓜籽和马铃薯 ;2 4个月后仍对油菜、甜菜、白菜和亚麻有严重药害。     

Activity,adsorption, mobility and field persistence of sulfosulfuron in soil

Petri dish bioassays, based on root response of corn grown in soil or in perlite, were used to study the activity, adsorption, mobility and field persistence of sulfosulfuron in a silty clay loam and a sandy loam soil. Both bioassays indicated that activity of sulfosulfuron increased with increasing herbicide concentration, and to a slightly greater degree in sandy loam soil than in silty clay loam soil. More sulfosulfuron was adsorbed on the sandy loam (not biologically available) than on the silty clay loam soil. Consequently, slightly greater amounts of sulfosulfuron were leached through the silty clay loam than through the sandy loam soil. Biologically available sulfosulfuron was not detected at depths below 40 cm after application in sandy loam, but this was not the case for the silty clay loam soil. In 2002, all sulfosulfuron rates showed field persistence of less than 5 months. On the other hand, in 2003, biologically available sulfosulfuron was detected in the 0–10-cm soil depth 150 days after application. http://www.phytoparasitica.org posting May 6, 2004.