小麦种芽对6种酰胺类除草剂敏感性测定

小麦种芽对６种酰胺类除草剂敏感性测定马式廉，袁树忠（江苏农学院植保系扬州２２５００１）江苏省麦田杂草发生及危害面积日益扩大，特别是推行麦田少免耕种植法后，麦田禾本科草的发生量呈上升趋势。使用绿麦隆防除麦田硬草、看麦娘等禾本科杂草的防效欠佳。近些年来，...     

稻茬免耕麦田恶性杂草发生危害和控制技术

稻茬免耕麦田恶性杂草发生危害和控制技术周益民，吉林，周国华，戴君淑，郦丘树（宜兴市农业局２１４２００）（无锡市植保站）（溧阳市化工厂）（善卷乡农技站）（丹阳市荆林乡农技站）近几年来，麦田草害问题突出，以禾本科看麦娘、日本看麦娘、草和阔叶杂草猪殃殃发生...     

江苏丰县地区麦田杂草发生特点及其治理对策

由于小麦品种频繁串换等诸多因素，近几年江苏丰县麦田杂草发生呈现三大特点，阔叶草优势种显著改变；禾本科恶性杂草面积和种类剧增；多数禾本科杂草群落组成呈现明显明显的区域性分布，为了有效控制麦田草害，必须采取加大统一供种力度，严格检疫，推广轮作灭草等农业防治措施及开展高产安全化学除草等一系列综合治理对策。     

麦田杂草损失率测定及防除指标研究

近几年来,由于耕作制度的变化,稻麦连作面积扩大和麦田少免耕技术的逐步推广,麦田杂草群落也发生了很大变化,草害也逐年加重。我市80年代后期麦田杂草以猪殃殃、繁缕、芥菜等双子叶杂草为主,占总草量的gi．92％。随着稻一麦一稻耕作制面积的不断增大,禾本科杂草逐年加重,看麦娘、硬草。棒头草等已成为稻茬麦田的主要杂草群落。1994年调查,禾本科杂草已占杂草总数的54．9％。麦田杂草已衍化为单双子叶杂草混生群落为主。为了解单双子叶杂草对小麦产量的影响。单双子叶杂草之间的相互关系,及单双子叶杂草混生条件下的防除指标,我们…     

老铁防除花生田杂草的效果

40％老铁WP防除花生田禾本科杂草、一年生阔叶杂草及莎草科杂草具有效果好、药效期长、杀草谱广、施药期较宽等优点。最安全的用法在花生播后苗前进行土壤处理，用药量150g／667m^2左右，对水量至少45kg／667m^2。     

小麦田除草剂异·乙的开发和应用技术研究

随着稻茬免耕麦面积的不断扩大，麦田草害越来越突出。异·乙除草剂杀草谱广，对禾本科杂草蔺草、日本看麦娘和阔叶杂草稻槎菜、碎米荠等都有较好的防效，对顽固性的早熟禾也有一定的效果。用40％异·乙WP120—150g／667m^2，在小麦播后15～25d（麦苗2—3叶期）对水喷雾，能有效控制小麦全生育期内杂草的危害，综合防效达95％左右，且对小麦安全，无残毒，操作方便。     

使阔得水分散粒剂防除麦田阔叶杂草试验简报

我市地处长江之滨，气候湿润，土壤墒情好。由于近年来推广稻套麦和免耕栽培技术，麦田杂草发生危害日趋加重，尤其是阔叶类杂草种类多、数量大，一般造成小麦减产３成以上。过去我市用于防除麦田阔叶杂草的药剂以使它隆为主，在冬前和春季两次使用，但仍不能控制阔叶类杂草的危害。因此，筛选麦田冬前一次用药全程控制草害的药剂显得尤为重要。２０００～２００１年我们选用６．２５％使阔得水分散粒剂防除麦田阔叶杂草，并对其防效及安全性进行了小区药效试验。材料与方法１，１ 供试药剂供试药剂有６，２５％使阔得水分散粒剂（法国安万…     

沛县麦田硬草发生与防除技术

沛县冬小麦常年种植面积超过4万hm2。麦田杂草优势种群是禾本科的硬草,占杂草总数的70%～80%,因其耐药性强,防除难度大,已成为本县麦田发生量最大的恶性杂草。1麦田硬草发生为害特点调查表明,本市麦田杂草以禾本科为主,主要有硬草、野燕麦、看麦娘、蜡烛草等,占全部杂草70%～90%。其次是阔叶杂草,如猪殃殃、婆婆纳、牛繁缕、麦加公、荠菜等,占全部杂草的20%～30%。杂草优势种硬草属越冬性一年生杂草。其发生特点是:①发生为害期长。一般10月份出土,一直为害到第2年的5月下旬。冬前出土量占发生量的80%～90%,冬后春季继续出土,占发生量的10%…     

50 g/L 唑啉草酯乳油防除大麦田杂草应用技术

50 g／L唑啉草酯乳油可安全应用于大麦田,有效防除硬草、看麦娘等禾本科杂草。50 g／L唑啉草酯乳油80～120 mL／667 m^2于杂草2～3分蘖期使用,药后90 d对硬草、看麦娘等禾本科杂草的防效仍高达95％以上,显著优于对照药剂50％异丙隆可湿性粉剂150 g／667 m^2处理。     

Syngenta（China）先正达（中国）

在两湖地区的冬油菜田,主要杂草有看麦娘、日本看麦娘、周草、棒头草、早熟禾等禾本科杂草和繁缕、牛繁缕、猪殃殃、婆婆纳、大巢菜等阔叶杂草,其中在稻茬油菜田里看麦娘、日本看麦娘、周草发生最多,危害最大,其发生量约占杂草总发生量的70％以上。在春油菜田,野燕麦、黎、地肤、芭买菜、茼麻等为主要杂草。     

Changes in agronomic practices and incidence and severity of diseases in winter wheat in England and Wales between 1999 and 2019

In continuation of the annual national surveys of winter wheat, which began in 1970, samples from between 250 and 350 randomly selected wheat crops in England and Wales between 1999 to 2019 were visually assessed for disease symptoms during the milky ripe development stages (GS 73–75). Septoria tritici blotch was the most prevalent and severe foliar disease each year, although annual levels fluctuated considerably and there was no overall significant change over the two decades. Incidence of brown rust, yellow rust, take-all, and barley yellow dwarf virus also showed no significant overall change during the survey period, whereas glume blotch, powdery mildew, eyespot, and sharp eyespot all showed significant decline. Fusarium ear blight has significantly increased in both incidence and severity, causing a serious epidemic in 2012, when 96% of crops were affected. Tan spot has been the third most prevalent foliar disease since 2009 although severity is still very low. Regional disease levels were consistent over the two decades, providing reliable baselines to measure changes in seasonal disease severity. There were significant changes in agronomic practice with a rise to predominance of minimum tillage over the use of ploughing, decreases in overall disease susceptibility of cultivars grown, a major increase in the use of oilseed rape in the rotation and a long-term trend towards earlier sowing. Fungicide use increased considerably, with over 98% crops sprayed and an average of 3.5 applications made per crop each year since 2014. Implications of changes over the last 21 years are discussed.     

中国的沙暴、尘暴及其防治

沙尘暴在进入 90年代以来有进一步加剧趋势 ,其原因在于此期我国西北地区气候干暖化态势明显 ,人类超负荷开发资源加剧 ,从而导致沙尘暴的频繁发生 ,但总体上仍属于正常的灾害现象。我国沙暴只能发生于干旱半干旱区 ,尘暴则可波及半湿润与湿润区 ,由此而论 ,北京的沙尘暴属于尘暴范畴 ,北京不会形成沙漠区。防治沙尘暴必须采取水、土、植被综合防治措施 ,基本对策是 :1 .搞好流域为单元的水土资源合理利用规划 ,进行水土保持综合防治 ;2 .增加地表植被复盖 ,搞好防护林体系建设 ;3 .减轻土地利用强度 ,恢复提高土地抗蚀能力 ;4.加强管理体系建设 ,依法建设生态环境。建议国家设立水土保持为主要职能的生态环境建设委员会 ,统一协调布署我国的生态环境建设工作。     

吡虫啉和百菌清在设施内外葫芦和黄瓜中的残留特性比较

采用高效液相色谱和气相色谱法,分别研究了吡虫啉和百菌清在薄膜大棚设施内外葫芦叶和黄瓜中消解动态及其在葫芦和黄瓜中的残留量,并结合气象因子对产生残留差异的原因进行了分析。样品中的吡虫啉经乙腈和盐酸溶液提取,中性氧化铝和弗罗里硅土层析柱净化后,用高效液相色谱检测;百菌清经乙腈提取,中性氧化铝层析柱净化后,用气相色谱检测。结果表明:吡虫啉在设施内外葫芦叶和黄瓜中均消解迅速,施药7 d后,其在设施内外葫芦叶上的消解率分别为90.4%和98.7%,在黄瓜中的消解率分别为67.8%和85.9%;而百菌清在葫芦叶上的消解速率均比在黄瓜中的稍慢,施药7 d后其在设施内外葫芦叶上的消解率分别为15.4%和38.1%,在黄瓜中的消解率分别为87.8%和91.5%。表明2种农药在设施外2种蔬菜上的消解速率均快于设施内的。两种农药均是在设施外葫芦及黄瓜中的残留量低于设施内的,而降雨和光照强度可能是引起农药在设施内外蔬菜上残留差异的主要因子。     

2017年与2014年西安极端高温天气及其环流特征对比分析

借助观测资料与FNL全球分析资料，对比研究2017年与2014年西安高温天气基本特征与有利环流形势，结果表明：① 2 a西安均发生了40 ℃以上的长时间持续高温天气，其中2014年属于常规高温年份，而2017年西安高温则提前1个月发生，高温的提前发生主要是因为南亚高压强于正常年份同期强度；② 不同于我国南方地区的闷湿高温，西安高温属于干性高温，且昼夜温差较小，由此造成24 h对人体的不适；③ 详细描述了西安高温发生的典型环流特征，即南亚高压与西太平洋副热带高压（简称副高）同时增强，并在对流层中高层相互贯通；④ 南亚高压是影响我国西北地区的主要热源基地，在较大经向度的有利环流背景下，强风速可将热气团向南向东深度输送至下游地区（即西安）；⑤ 在“上辐合、下辐散”的散度场配置下，西安500 hPa以下高空维持明显的下沉气流，加之有利的局部要素相配合，最终造成该地区高温天气的发生。     

Plant-pathogen interactions of sunflower and Macrophomina phaseolina in vitro and in vivo

The relative pathogenicity of isolates of Macrophomina phaseolina was comparable both on sunflower tissue cultures and on mature plants and seedlings. The relative susceptibility of the different sunflower lines in vitro showed a similar pattern for cotyledon callus cultures, but not for immature embryo cultures. Although these protocols appear to be unsuitable for the selection of novel disease resistance, they do offer the potential for a rapid, non-destructive screen for resistant material.     

Trends and expectations for research and technology in weed science in Thailand

There are many possible ways to improve the economic crisis in Thailand, and it is agreed that development of agricultural production is ideal for improving the economic situation in an agricultural country such as Thailand. A strategic plan for agricultural and agro‐industry research is included in the national research agenda and can be classified into nine groups covering different research areas. Most research is based on the agricultural production of four main product groups: (i) crops; (ii) aquatic animals/plants and fisheries products; (iii) poultry, livestock and animal products; and (iv) forest resources. Trends in research and development in weed management for crop production will continue to support the food demands and the development of efficient production of quality products.     

Pesticide residues in soil and foodstuff I. Chlorinated pesticides in cattle feed and milk produced in orchard and non-orchard areas

Milk, hay and silage produced in orchard and non-orchard areas have been analysed for their content of chlorinated pesticides. The residue levels in milk produced in orchard areas were about double those in milk produced in non-orchard areas. The levels in hay were much higher (30% up to sevenfold) in the hay produced in orchard areas and the levels in silage from the two areas showed small differences. Milk collected after cattle had been grazing in an orchard for 3 to 4 days contained 10% more pp′-DDT and 2-, 3-, 7- and 15-fold morepp′-DDE, pp′-TDE and heptachlor epoxide, gamma-BHC and pp′-TDE olefin [1-chloro-2,2-bis(p-chlorophenyl)ethylene], respectively, than did the samples collected one day before the cattle grazed in the orchard.     

Comparative ecophysiology of grain sorghum and Abutilon theophrasti in monoculture and in mixture

Selection of crop genotypes that are more competitive with weeds for light interception may improve crop yield stability in the presence of weeds. The effects of interference on ecophysiological characteristics of Abutilon theophrasti Medic. and three morphologically diverse grain sorghum hybrids was evaluated to determine the relative tolerance and suppressive ability of the three hybrids and specific traits that may contribute to those differences. A tall hybrid was more tolerant to A. theophrasti interference than two medium stature hybrids. Early leaf area growth of two medium-stature sorghum hybrids was reduced by A. theophrasti interference, whereas early growth of a tall hybrid was unaffected. The height of A. theophrasti was greater than two moderate-stature hybrids but lower than the tall hybrid. Greatest leaf area density (L_D) of the tall sorghum hybrid was above that of A. theophrasti , whereas greatest L_D of medium-stature hybrids was below that of the weed. In monoculture, the partitioning of new biomass to various plant organs was similar among sorghum hybrids, whereas the tall sorghum hybrid partitioned less biomass to leaves and more to stems than medium hybrids in mixture. The results indicate that the three hybrids differ in their susceptibility to A. theophrasti competition. Crop traits that may contribute to greater crop competitiveness include greater maximum height and its growth rate and greater height of maximum leaf area distribution.