水稻条纹叶枯病的为害损失及防治指标

2004-2006年在浙江北部系统地调查了水稻条纹叶枯病发病动态和为害损失。单季晚稻秧田期介体灰飞虱有效虫量（X2）与水稻株发病率（Y1）的关系式为Y1=0.0873 + 1.0757X2,晚稻本田株发病率（X）与产量损失率（Y）总关系式为Y=0.1254+0.7551X。在现有生产条件下,经济允许水平以损失率表示为2.0%~2.5%,制订了水稻条纹叶枯病防治指标为水稻秧苗期和本田前期介体灰飞虱有效虫量2~3头/m2,该指标已在生产上大面积推广应用。     

白叶枯病对水稻产量影响测定

白叶枯病(Xanthomonas CampestrispV.Oryzae)是我省水稻重要病害之一,特别在沿海平原区,每年都有不同程度发生为害,尤以晚季发病重于早季,倒种品种、杂优稻发病重于常规晚稻品种。为了明确白叶枯病对水稻为害的损失程度,分别对受害不同程度的稻株进行收割、考种测定,为防治白叶枯病和估产损失程度提供依据。供测品种: 常规晚稻品种广矮2号和倒种珍珠矮品种,在长乐县鹤上村种植面积都在50亩以     

水稻白叶枯病的发生危害与综合防治技术探讨

水稻白叶枯病近年来在仙居县呈上升流行态势,对水稻高产稳产构成极大威胁。为探索新的耕作栽培条件下水稻白叶枯病的发生流行规律与综合防治对策,笔者系统调查了水稻白叶枯病的发生危害、侵染循环和影响因素,探明了病害再度上升的主要原因,提出了病害防控的对策与综合防治技术。     

北方水稻主要病虫害的识别与防治技术

介绍了立(黄)枯病、恶苗病、细菌性褐斑病、烤苗等水稻苗期病害的发生条件、发病症状及防治方法等,总结了稻瘟病、赤枯病、白叶枯病、稻曲病等水稻本田病害与潜叶蝇、负泥虫、稻水象甲、二化螟、粘虫等水稻本田虫害的发生、危害及防治。加强水稻生产管理,正确防治水稻病虫害,是保证水稻品质、提高产量的必要手段。     

盘锦稻区水稻潜叶蝇发生与产量损失的关系

为探明水稻潜叶蝇在盘锦稻区的发生特点及对水稻产量的损失情况,2014年,在盘锦大洼县王家镇和盘山县胡家镇进行了水稻潜叶蝇的观察和研究,结果表明,盘锦稻区水稻潜叶蝇以第2代为害为主,发生期集中在5月25日至6月25日,在百株水稻虫口密度为25、50、75、100头时,为害差异显著,当虫口密度为75/百株时,需引起重视,当抽口密度上升到100头/百株左右时,对水稻产量的损失已达到20%,因此,此虫口密度下必须防治。     

水稻品种的多抗性鉴定

稻瘟病、白叶枯病,褐稻虱和白背飞虱是福建省水稻最主要的病虫害,每年都有不同程度的发生及为害,遇到病害大流行、害虫猖獗的年份往往导致水稻严重减产。推广抗性良种是水稻病虫综合防治的关键措施,我们采用国际水稻所研制的鉴别品种及筛选技术,已成功地进行了水稻品种对上述两病两虫的多抗性鉴定。一稻飞虱测定方法:采用大型水泥测定池,池内土厚18～2l厘米,每个品种播15～20粒,播后盖上尼龙沙罩。一叶一心期接虫,每     

稻小球菌核病分级标准和为害损失率的测定

稻小球菌核病是水稻上较为常见的一种病害,近年有不断加重发生的趋势。对稻小球菌核病进行分级和对其为害损失进行测定,有助于对该病防治指标的制定。调查统计结果表明,采用稻茎秆基部发病情况和菌丝菌核形成情况相结合的分级标准是切实可行的。     

芗城区发生甘蔗白叶枯病初报

甘蔗白叶枯病早在1928年Ｆａｒｌｅ.Ｆ.Ｓ.氏就记述过,继后Ｍａｒｔｉｎ.Ｊ.Ｐ氏于1938年,Ｋｏｉｌｋｅ.Ｈ.氏于1968年,分别在夏威夷、美国报告发生。现此病已遍布于澳洲、非洲、美洲和南亚诸国。一、为害性本病在我区各镇种植区、普遍零星发生,个别严重发生的是品种703宿根蔗,株发病率达72.6%,严重度达36.8%,此病为害导致了蔗汁的糖份降低。(见表1)。二、症状及病原菌白叶枯病仅为害嫩叶,多数是心叶第一、二叶,个别第三叶,较老叶片不受害。但已被侵染的叶子在老叶过程中病斑可继续扩张,直至近叶梢。病状先从叶尖或叶缘开始,初为水渍状条纹,…     

23%满穗防治水稻纹枯病药效试验

水稻纹枯病是水稻主要病害之一 ,且为害时间长 ,从分蘖至成熟期均可为害 ,为害损失一般年份已超过稻飞虱 ,严重的造成白穗甚至倒伏。多年来防治纹枯病的主导药种一直是井冈霉素 ,药剂单一 ,防病持效期较短。为此 ,引进一种防治水稻纹枯病的特效新农药——— 2 3%满穗悬浮剂。为验证 2 3%满穗悬浮剂对水稻纹枯病的防治效果 ,于 1999年在瓜后稻和双晚移栽田进行了药剂试验示范 ,现将结果小结如下 :1　材料与方法1 1　试验药剂2 3%满穗悬浮剂 (美国罗门哈斯 ) ;5%井冈霉素水剂 (浙江钱江生化集团 )。1 2　试验方法1 2 1　防治瓜后稻纹枯病…     

寒地水稻白叶枯病发生特点与综合防控技术

水稻白叶枯病作为黑龙江省植物检疫对象,2004年在桦南县首次被发现并迅速扩展蔓延,严重威胁着全县及周边地区的水稻生产安全.通过对水稻白叶枯病的发病症状、传播途径、影响因素和发生危害特点等的调查研究,从做好植物检疫、选用抗病品种、实行轮作制度、加强水肥管理、抓好药剂防治等方面提出了寒地水稻白叶枯病综合防控技术.     

草地贪夜蛾不同虫口密度对海南鲜食玉米产量的影响及其经济阈值研究

草地贪夜蛾[Spodoptera frugiperda (J. E. Smith)]在海南省可周年繁殖,世代重叠严重,常年危害海南鲜食玉米,防治困难。为了解海南省不同虫口密度草地贪夜蛾幼虫在鲜食玉米各个阶段对其产量的影响,采用田间接种不同密度3龄幼虫的方法来模拟自然危害,研究其经济阈值。结果表明,苗期（4~6叶）、喇叭口期（8~10叶）和抽穗期（12~14叶）各阶段,虫口密度与危害程度的回归方程分别为：y=0.06ln(x)+0.1258、y=0.0546ln(x)+0.1863、y=0.0589ln(x)+0.0275,计算出不影响玉米产量的危害程度分别为：21.57%、28.34%、14.50%。虫口密度与总产量在苗期（4~6叶）、喇叭口期（8~10叶）和抽穗期（12~14叶）的回归方程分别为：y=-0.2508x+13.113、y=-0.1093x+12.721、y=-0.0616x+12.447,得出不影响产量的虫口密度分别为：5头/20株、7头/20株、9头/20株;各时期的经济阈值分别为：6~8头/20株、12~20头/20株、19~24头/20株。该研究结果为海南省鲜食玉米田草地贪夜蛾的精准防治及合理的农药减量提供科学依据,对提高防治经济效益、保护生态环境等具有重要意义。     

水稻潜根线虫的致病性和综合防治技术

 接种试验证实潜根线虫侵染水稻能引起减产,主要是减少有效穗和千粒重;返青期为感病期,这一时期每株稻苗接种300条和470条潜根线虫,分别减产8.8%和13.5%。综合防治措施包括烟 稻轮作、稻草还田、冬翻冬种、利用耐病品种和药剂防治。返青期为防治适期。     

黑龙江省水稻稻瘟病的分析与对策

针对近几年黑龙江省稻瘟病大面积发生造成水稻减产问题,通过对历年的水稻产量、气象资料以及实地调查结果,分析了稻瘟病发生原因,并提出加强栽培管理,提高抗病能力;重视综合预防,减少病原基数;把握关键时期,必须药剂防治等预防对策。     

A bioeconomic model of downy mildew damage on grapevine for evaluation of control strategies

In order to reduce pesticide use in vineyards, we propose a bioeconomic model to evaluate different fungicide treatment strategies. This model estimates the development of the downy mildew Plasmopara viticola for a given year's weather on a grapevine plot, and predicts the damage done, the yield loss, and the resulting partial gross margin, depending on the chosen protection strategy.Grapevine growth and phenology are simulated with the STICS grapevine crop model according to the year's weather; fungal components quantify downy mildew development; damage onto leaves and fruits is characterized as a percent reduction of potential leaf area and yield; the effect of fungicide treatments is simulated as a partial protection against infection; the economic result is calculated at plot level, taking into account simulated yield, local economic conditions and costs of observations and sprayings.The model parameters were estimated using three sets of experimental data from vineyards in the French wine-growing region of Bordeaux. Using these parameter values, the model was used to evaluate the following five protection strategies: 3 systematic fungicide spraying strategies with 2-, 3- or 4-week intervals, the “Mildium” adaptive strategy, which includes field observations and decision rules, and a control untreated strategy. Yield losses and the resulting partial gross margins were calculated for 23 annual weather examples for each strategy and the statistics of these strategies were compared. The adaptive strategy was found to be slightly less protective on average against downy mildew than the 2-week systematic spray strategy. However its low variability ensures sustainability in terms of grower's income, while reducing by one third the number of sprayings. The model hypotheses and simulation results are discussed, in relation to the particular economic context of the “Bordeaux” protected designation of origin with the objective of reducing pesticide use in vineyards.     

湖北发生的水稻矮缩病是南方水稻黑条矮缩病毒引起的

 近年来由水稻黑条矮缩病毒和南方水稻黑条矮缩病毒引起的水稻黑条矮缩病在华南、华东等地区暴发流行,给水稻生产带来严重损失,而湖北一直未有水稻黑条矮缩病流行的报道。然而,2009年和2010年在湖北省长江沿线的荆州、孝感、咸宁、黄石、鄂州、黄冈等水稻种植区普遍发生水稻矮缩减产的现象。经过症状观察、dsRNA电泳图谱分析、RT-PCR等方法,诊断该病是由南方水稻黑条矮缩病毒引起,说明该病毒已经随介体昆虫白背飞虱从我国南方传播至中部水稻种植区。     

早稻穗期白背飞虱为害损失及防治指标研究

 笼罩接虫试验丧明，早稻穗期产量损失(Y )与每丛白背飞虱数量(x)的关系符台方程： Y=14.0835+10.9425X士28.95。 产量损失的主导原因是水稻受害后秕谷率增加。根据目前稻谷价格、防治费用等，导出白背飞虱防治指标为每丛l12～16头。经大田验证，与实际基本相符。     

Crop loss of pepper plants artificially infected with Xanthomonas campestris pv. vesicatoria in relation to symptom expression

Crop losses in peppers artificially infected with Xanthomonas campestris pv. vesicatoria (XCV) were determined during 3 years of field experiments in three areas of Israel. Direct losses of 23–44% in fruit yield were recorded when severe leaf infection occurred or was induced at an early stage of plant growth. Yield losses and disease index were markedly lower in plants inoculated at later stages and near maturation. Indirect losses in severely infected fields were mainly due to shedding of leaves and exposure of fruits to sun. In this case, up to 95% of the fruits lost their commercial value. In artificially infected symptomless plants with massive endogenous populations of XCV in the leaves, a loss of 24% in yield was measured, compared with plants free from an endogenous pathogen population.     

岳优9113作烟后稻机械插秧高产栽培技术

机械插秧具有效率高、降低生产成本、减轻劳动强度,便于合理密植、提高基本苗,适合带土、带药、带肥移栽,促使禾苗早生快发,促进水稻增产增收等优点,近年来得到迅速推广。试验以岳优9113为例,从播种育秧—机械插秧—田间管理各环节,阐述烟后稻机插高产栽培技术。     

Induction of resistance in rice plants to insect pests by the application of chelated metal complexes

A study evaluated the efficacy of 13 chelated metal complexes in inducing resistance in rice plants to yellow borer, gall midge, and rice caseworm. Plant characters such as height, number of leaves, number of tillers and grain yield were recorded. Plants sprayed with boron and zinc chelates were relatively taller than the others. Production of leaves and tillers was enhanced by some treatments. Plants sprayed with B-oxytetracycline had maximum grain yield. Insect-pest incidence varied in different plots and was considerably lower than in the control plots. The possible mechanism of induced resistance is discussed. Chemical analysis of treated plants has shown that application of metal chelates caused various changes in plant composition.