2003年全州县晚稻稻纵卷叶螟发生为害重

稻纵卷叶螟是广西全州县水稻主要害虫之一,在早稻发生为害重,晚稻发生为害轻,常年晚稻为轻发生,个别年份中等偏轻发生,发生面积在1万hm^2以内,占种植面积的35％以下。2003年全州县晚稻发生了历史罕见的稻纵卷叶螟,全县晚稻种植面积2．12万hm^2,发生面积1．31万hm^2,占种植面积     

2006年与2007年稻飞虱发生及防控策略

钟祥市常年水稻种植面积4万hm^2左右，耕作制度为麦稻和油稻连作，全部为一季中稻。2006年、2007年稻飞虱连续大暴发，给水稻生产构成严重威胁，2006年水稻种植面积4．17万hm^2，总产50．5万t，因各种原因导致稻飞虱防治效果较差，穿顶面积达240hm^2，损失稻谷5．63万t，损失率达10．03％。2007年水稻种植面积4．19万hm^2，因水灾绝收面积1333hm^2，实收面积比2006年减少1067hm^2，总产55．1万t，比2006年增4．6万t，因认真落实防控措施，     

岳池县农作物病虫专业化统防统治的成绩

2011年岳池县各级政府高度重视农作物病虫专业化防治组织建设工作．采取各项有力措施．积极开展农作物病虫专业化统防统治工作．共实施水稻、玉米病虫害专业化统防统治面积1．8万hm^2（水稻1．6万hm^2、玉米2000hm^2），占水稻病虫害防治面积的22．22％和占玉米病虫害防治面积16．24％，挽回粮食损失262．87万kg．取得了预期的防治效果和成绩。     

玉林市早稻稗草发生为害较重

玉林市2004年早稻稗草为害较重,是多年来未见过的。据在水稻后期组织各地普查后推算。全市稗草发生面积5．46万hm^2。占种植面积40．91％,为害面积1．66万hm^2,占种植面积12．45％;其中为害较重的(有稗草20株／m^2以上)面积0．31万hm^2。为害重的田块有稗草53～88株／m^2;一般有5～20株／m^2,一些不及时除稗的田块损失产量达5％～100局。由于稗草发生较重,杀稗王、灭稗净等二氯喹啉酸的除草剂销售好,并曾一度出现脱销现象。     

宜昌市农产品质量安全状况研究

宜昌地处长江中上游的结合部,属亚热带季风气候,盛产茶叶、柑桔、水稻、蔬菜、油菜等农业农产品,其中茶叶常年种植面积2万hm^22,柑桔4．67万hm^2,水稻8．67万hm^2,蔬菜7．53万hm^2,油菜8万hm^2。产量和种植面积均位居湖北省前列。     

正阳县旱稻田杂草的发生与防治对策

正阳县常年种植水稻2万hm^2．旱稻的种植面积在逐年增加,2008年已增至1万hm^2．水稻面积同比下降。2009年国家提高了稻谷的收购价格．种旱稻的比较效益显著提高．种植面积将继续增加．种植区域已从水稻种植区扩展到旱作区。与此同时,旱稻田的杂草草相也在发生变化．以稗草为主的杂草越来越难以防除．防治成本也在增加．已成为旱稻生产亟待解决的问题．     

2003年水稻螟虫发生特点及原因分析

2003年我市水稻种植面积为2．4万hm^2,其中中稻2．36万hm^2,二季晚稻0．04万hm^2。由于气候条件、水稻品种等相关因素的影响,水稻二化螟猖獗为害,三化螟成为次要害虫。     

水稻二化螟的发生与防治技术

隆昌县常年种植水稻2．1万hm^2左右．占粮食种植面积的76．51％．为主栽品种,水稻上的重大虫害主要是二化螟。为了有效防治二化螟的为害．减少农药残留量和环境污染,净化水域环境．保护水生动物．最大限度扩大水稻的绿色成分,笔者研究探索了二化螟的生物学特性,找准防治的最佳时期．选用高效低毒低残留的农药．推广生物防治．示范“稻鸭共育控螟”技术．取得了较好的效果。     

2009年南漳县稻飞虱发生特点及原因分析

2009年,南漳县水稻共发生稻飞虱2．93万hm^2次,防治3．6万hm^2次,挽回损失1．44万t,实际损失400t,仅次于2006年,重于2007年和2008年。其中3代白背飞虱发生2．27万hm^2,占全县水稻面积2．28万hm^2的99．4％,达到特大发生水平;第4代褐飞虱发生1万hm^2,达到中等偏重发生水平。     

阳新县2013年稻飞虱发生原因分析

阳新县地处长江中游南岸,鄂东南丘陵地区。水稻是我县主要粮食作物,常年种植面积4．1万hm^2。稻飞虱是阳新县水稻常发性害虫,2013年我县稻飞虱中等偏重发生,因受长期高温干旱特殊气候影响,发生面积3．74万hm^2,防治面积达3．5万hm^2。     

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.     

北京地区明代、清代干旱灾害与气候事件研究

根据北京地区历史时期旱灾资料,利用数学统计方法中的参数区间估计研究了明清时期该地区旱灾的差异和气候的不同。结果表明：在北京地区明代（1368-1643年）276年内,共发生旱灾166次,平均1.66年发生1次;轻度旱灾47次,中度旱灾56次,大旱灾55次,特大旱灾8次。在清代（1644-1912年）的269年里,共发生...