襄樊市2001年优质水稻主要病虫发生特点及原因分析

20 0 1年襄樊市水稻种植面积 1 5 .8万 hm2 ,其中优质水稻主要品种有 :两优培九、湘晚籼 9号、扬稻 6号、金优系列、粤优 38等 ,优质稻播种面积最大的品种是两优培九和湘晚籼 9号 ,分别为 5万hm2和 0 .73hm2。较 2 0 0 0年分别增加 3.93万 hm2和 0 .33万 hm2。我市优质稻作为一季中稻种植 ,大部分熟期偏晚 ,正值多种病虫集中暴发期 ,加之优质水稻具有特殊气味 ,长势、长相和较好的品质 ,也成为各种病害重发田和害虫的诱集田。 2 0 0 1年全市优质水稻病虫总体发生趋势是病虫兼重 ,发生程度不均衡。据统计 ,2 0 0 1年优质稻各种病虫发生面积67…     

荆州市2001年优质稻病虫发生特点及原因分析

近几年来 ,随着我市种植结构的调整 ,优质稻在我市推广种植的面积不断扩大 ,已成为我市水稻生产的主导品种。 2 0 0 1年荆州市优质稻种植面积达1 3.33万 hm2 ,占水稻种植面积的 35 %以上 ,主要分布在监利、松滋、公安、石首、洪湖等县市 ,其品种主要有 :舟优 90 3、中鉴 1 0 0、嘉育 948、荆优早1 0 4、鄂早 1 2、两优培九、扬稻 6号、中国香稻、 优 5 0 1、金优 92 8、湘晚系列等。优质稻虽有高产、优质、高效等特点 ,但在田期间其病虫发生与普通水稻也有一定的区别。现将我市优质稻病虫发生的主要特点及原因分述如下。1　优质稻病虫的主…     

广西2003年农作物主要病虫发生趋势分析

20 0 3年广西农作物计划种植面积中 ,粮食作物播种面积有所减少 ,经济作物播种面积比 2 0 0 2年增加约 5 .5 % ,果树新增种植 3 .3 3万 hm2 次。根据2 0 0 2年农作物病虫发生实况、2 0 0 3年种植结构以及历史资料综合分析 ,预计 2 0 0 3年广西农作物主要病虫总体发生将轻于 2 0 0 2年 ,属常发年份 ,发生程度将达中等偏重 ,发生面积约 1 3 3 5万 hm2 。稻飞虱、玉米铁甲虫、稻纹枯病等病虫在局部地区将达大发生。1　主要病虫害发生趋势预测1 .1　水稻病虫发生比 2 0 0 2年稍轻 ,发生程度 4(5 )级 ,发生面积 5 3 0万 hm2 次。其中 :　　稻飞虱…     

枝江市2013年农作物病虫发生特点及原因分析

枝江市位于宜昌东部,荆州以西,为江汉平原与丘陵山区过渡地带,2013年水稻种植面积2．8万hm2,其中早稻0．7万hm2,中稻1_3万hm2,晚稻0．8万hm2,棉花种植面积1．6万hm2,小麦种植面积1．7万hm2,油菜种植面积1．9万hm2,柑橘种植面积2．1万hm2,蔬菜种植面积1．3万hm2。2013年病虫综合平均发生程度为中等,农作物病虫害累计发生面积60．1万hm2次,防治面积72．1万hm2次。     

襄樊市蔬菜种类及主要病虫发生特点

20 0 2年襄樊市蔬菜播种面积7 35万hm2 ,较上年增 0 17hm2 ,其中食菜类为 6 4 1万hm2 ,藕 0 94万hm2 ,较上年增0 0 9万hm2 ,西瓜1 80万hm2 ,较上年增 0 0 9万hm2 。年产蔬菜 4 6 9 6 9万t。由于近年来蔬菜新品种的不断引进 ,保护地蔬菜面积逐年加大 ,蔬菜病虫害发生呈逐年加重的趋势。据统计 ,蔬菜病虫发生面积为 2 1 85万hm2 次 ,防治面积达到 34 2 2万hm2次 ,挽回损失 25 0 3 0万t。1　主要蔬菜种类除保护地外 ,我市露地蔬菜仍以春、夏两季种植为主 ,夏季辅助小杂品种。春季种植主要品种有 :辣椒、黄瓜、番茄、茄子、西葫芦、包菜、…     

荆州市稻瘟病发生特点及防控技术

水稻是荆州市的主要农作物之一,常年种植面积33·67万hm2左右,其中早稻7万hm2,中稻18·67万hm2,晚稻8万hm2。病虫害是妨碍水稻高产、优质的关键因素,抓好水稻病虫害的防治,提高水稻产量和品质,对促进荆州市农业和农村经济的发展,保持农村稳定,构建和谐社会,具有十分重要的意义。稻瘟病是荆州市水稻上的重要病害之一,近几年来随着对水稻品质要求的提高,优质稻的种植面积在不断扩大,由此稻瘟病也越来越严重,给本地的水稻生产构成了严重威胁。1发生特点荆州市稻瘟病平均每年发生面积约6·67万hm2,占种植面积的20%左右。其发生的主要特点是:一是…     

邕宁县2001年西瓜主要病虫害发生概况及综合防治措施

西瓜是邕宁县主要农产品之一 ,2 0 0 1年种植1 .682万 hm2 (这里指的是早造面积 ,晚造 0 .2 7万hm2左右 ,这里不作陈述 ) ,是全国有名的第 2大西瓜生产县。今年是西瓜病害发生较重的一年 ,发生面积 1 .2 9万 hm2 次 ;虫害发生偏轻 ,发生面积 0 .487万 hm2 次 ,病虫害发生面积共 1 .777万 hm2 次。现将今年西瓜主要病虫发生为害概况和综合防治措施分述如下。1　发生为害概况1 .1　猝倒病 :苗期病害 ,发生面积 0 .0 4万 hm2 ,病株率最高 1 1 .5 % ,一般 2 %～ 7% ,发生程度属轻 ,局部中偏轻发生。1 .2　西瓜疫病 :属鞭毛菌亚门真菌 ( Phytoph…     

随州市2014年稻瘟病发生原因及防治对策

<正>随州市是一个农业大市,属丘陵地区。农业生产以种植业为主,粮食比重较大,常年种植水稻11.33万hm2。稻瘟病是水稻上重要病害之一,近年来其发生和危害程度呈逐年加重趋势,以2014年发生最为严重。现就随州市2014年水稻稻瘟病的发生特点及防治情况进行分析。1稻瘟病的发生特点1.1发生面积大、损失重统计显示今年我市稻瘟病的发生面积为3.05万hm2,全市各县市区都有不同程度发生,其中     

运用锐劲特防治稻田螟虫试验示范

我市位于鄂西南,常年种植水稻面积5.67万hm2～5.87万hm2,在布局上,早晚稻面积大,中稻面积小,以三熟制为主体的种植模式。近年来为了大力发展优质稻,在布局上做了调整,即优质中稻发展到1万hm2以上,水稻总面积调减为5.2～5.33万hm2。     

广西2001年农作物主要病虫发生概况

20 0 1年广西农作物主要病虫的发生重于 2 0 0 0年 ,但仍是一个常发生年份 ,总体发生程度属中等偏重 ,全年发生面积约为 1 41 5 .5 7万 hm2次 ,防治面积 1 31 4.2 4万 hm2 次 ,防治挽回损失 5 2 8.86万 t,实际损失 90 .87万 t。其中 :　　水稻病虫发生程度 4( 5 )级 ,发生面积 5 70 .87万 hm2次 ,发生面积占种植面积的 2 5 5 .0 2 % ,比上年增加了 3.6个百分点 ,防治后挽回稻谷损失1 77.82万 t,实际损失 2 2 .1 5万 t。其中重发生的病虫有稻飞虱、稻纹枯病 ,中等程度发生的有稻纵卷叶螟、稻瘿蚊 ,偏轻发生的有三化螟、稻瘟病和细菌性条斑病…     

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.     

Incidence of benomyl and iprodione resistance in isolates of Botrytis cinerea in tomato crops in England and Wales in 1986

In 1986, mass-mycelial isolates of Botrytis cinerea from 67 tomato crops in England and Wales were examined for benomyl and iprodione resistance. Of the 706 isolates obtained, 62.7% were resistant to benomyl at 2μg/ml and 43.2% were resistant to iprodione at 2 μg/ml. Iprodione resistance persisted in the absence of a dicarboximide spray programme. The incidence of benomyl resistance has not decreased since the last survey in 1984 in spite of a considerable reduction in the use of benzimidazole fungicides. There were no clear indications that the use of dichlofluanid influenced the incidence of benomyl or iprodione resistance. Disease control was poorer in crops with a higher incidence of iprodione resistance.     

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.     

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。     

西部降水氢氧稳定同位素温度及地理效应

本文基于IAEA和WMO建立的GNIP网降水资料,得出中国西部地区大气降水线方程(LMWL)为δ2H=7.56δ18O+5.05‰(VSMOW)。分析了降水中氢氧稳定同位素温度效应、地理效应,确定了降水中δ18O和δ2H与月平均气温、降水量、海拔高度、纬度的相关关系。根据张掖站降水δ18O与温度之间的相关关系和民勤地下水14C年龄和δ18O特征,初步重建了晚更新世以来民勤盆地地下水补给温度,并与惰性气体补给温度(NGT)进行了比较,其相关系数为0.65,晚更新世地下水的补给温度(据δ-T关系)较大,可能是没有考虑降水量效应的缘故。     

西安夏、秋季降水与太阳黑子的关系

基于西安市1960-2007年的降水数据和太阳黑子相对数,采用一元线性回归、Mann Kendall检验等方法,对西安降雨量进行分析,然后采用小波分析方法研究了西安夏、秋两季降水量与太阳黑子之间的关系。结果表明：夏、秋两季降水量约占西安全年降水量的80%;西安夏季降水量呈上升趋势,秋季降水量则呈下降趋势;降水量的变化与太阳黑子数多少密切相关,在太阳黑子出现极值年及2 a左右,降水量也出现极值;西安夏季降水量有10 a左右的周期,秋季降水量有9 a左右周期;太阳黑子在9 a时间尺度上与降水量有很强的相关性,且夏季降水量与太阳黑子相差1～2 a的正相关,秋季降水量则与太阳黑子提前2 a左右的负相关关系。     

Build-up and subsequent decline of residues of quintozene and hexachlorobenzene in lettuce in sequential crops

The build-up and decline of quintozene and hexachlorobenzene residues in protected lettuce, resulting from one to five treatments of the soil (each of 35 g m-2) with a quintozene formulation, have been studied. Residue levels were monitored in each experimental crop during growth until harvest. Residues in the soil at harvest were also determined. Quintozene residues in the harvested lettuce were in the range < 0.02–0.80 mg kg^?1 and those of hexachlorobenzene were in the range < 0.02–0.05 mg kg^?1 (expressed on a fresh weight basis). Residue levels in the soil were 5.4–231 mg kg^?1 for quintozene, and 0.20–5.4 mg kg^?1 for hexachlorobenzene (expressed on a dry weight basis). Under the experimental conditions of the trial there was no significant build-up of quintozene or hexachlorobenzene in harvested lettuce, even after five treatments to the same site.     

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.     

2009年融水县早、中稻稻瘟病大发生及流行因素分析

<正>稻瘟病(Pyricularia oryzae Cav)长期以来一直是为害融水县水稻生产的主要病害[1],为全县双季稻及早、中稻混栽区内常发性病害,历年发生面积333.3～533.3 hm2,尤其是一些历史老病区受此病为害,常造成水稻产量较大损失。2009年该病又相继在早、中