气候变化对山西省冬小麦种植的影响

以1961-2005年地面气象观测资料和冬小麦生长发育资料为基础,分析了山西省气候要素及关键界限温度等变化趋势和特征。结果表明:山西省年平均气温增温明显,最冷月平均气温稳定上升,其倾向率为0.42℃/10 a;冬、春两季增温明显,其中冬季气温上升尤为显著;年平均气温和极端最低气温等值线北移较明显;降水量总的趋势在减少,秋、夏两季节降水量下降趋势以及阶段性都较明显,冬、春季总降水趋势不太明显,但阶段性起伏比较大;年平均日照时数也呈下降趋势。≥0℃积温、降水量和日照时数较1960年代在区域分布上东南部地区则较正常,其余地区呈增加、减少趋势。经M-K检验可知,自上世纪70年代末、90年代初开始温度升高、降水减少趋势开始明显,并在1998年通过U0.05显著性检验,从1990年代开始的气候暖干旱化趋势明显。气候变化使冬小麦播种和越冬期推迟,从返青开始各发育期均有提前,冬小麦种植北界较1960年代北移约15km左右。     

河南省冬小麦气候干旱风险评估

冬小麦生育期内降水亏缺,不能满足作物的需要,是形成冬小麦气候干旱的首要条件.本文从自然降水角度,分析了河南省干旱发生的强度、概率和对冬小麦产量的影响,构建了冬小麦气候干旱风险模型.在此基础上,对河南冬小麦干旱风险进行了评估、分区.     

河北省冬小麦气候适宜度动态模型的建立及应用

运用模糊数学理论结合前人研究成果,建立了冬小麦温度、降水、日照隶属度模型和气候适宜度模型,分别计算了河北省冬小麦1960～2005历年全生育期和各发育期的温度隶属度、降水隶属度、日照的隶属度和气候适宜度.结果表明,河北省冬小麦温度隶属度和日照隶属度较大,光热资源一般条件下能够满足冬小麦生长发育要求,降水隶属度较小,降水条件是冬小麦产量形成的限制因素.冬小麦气候适宜度为下降趋势,10年下降速率为0.012.冬小麦各发育期气候适宜度以分蘖期、返青期、拔节期变化幅度较大,这与河北省的天气特点是一致的.     

水分胁迫持续时间对冬小麦根冠生物量累积的影响

为了解冬小麦根、冠对土壤含水量变化的响应,对不同水分条件下温室盆栽冬小麦作了分析研究。该试验包括七个水分状态,充分供水A处理(75%~100?,FC为田间持水量),中度胁迫B处理(55%~65?)和重度胁迫C处理(35%~45?)以及分蘖期开始中度、重度胁迫到孕穗期复水的BA1、CA1处理和抽穗期复水的BA2、CA2处理。试验结果表明:分蘖期开始的水分胁迫无论何时恢复供水都不影响冬小麦根、冠生长过程的总趋势;但随胁迫程度、胁迫持续时间的增加,胁迫期内根、冠的相对生长率,根、冠总重均降低,但根重占有量增大,且水分供应量的减少和胁迫时间的延长使冬小麦生育周期提前结束;随胁迫的增加,胁迫时间的延续,最大根重减小,但较大根重维持的时间延长;当复水后,各处理对复水存在不同程度的滞后效应和激发补偿生长,导致短期胁迫的根重占有量小于长期胁迫处理,中度胁迫小于重度胁迫,冠重也随之改变。造成此现象的原因:水分胁迫影响植株的功能,但自适应能力的作用促使分配于根系的同化物质增加,改善和提高根系的吸水能力,缓减植株由于缺水造成损失;对于供水超过75?的植株,生育后期的冠重占有量较小,根重较大则归因于生长过程已形成的庞大根系。     

河北省干热风对冬小麦千粒重的影响评估

干热风对冬小麦千粒重的影响评估是农业气象服务的一个重要内容。文中选取河北省冬麦区涿州、栾城、南宫、肥乡农业气象观测站资料,考虑干热风日土壤墒情、冬小麦品种等因素,分析干热风天数与千粒重、相对千粒重的相关性,确定影响干热风与千粒重关系的主要因子,建立了干热风评估模型。结果表明:灌浆期轻度干热风天数与千粒重相关不显著,重度干热风天数与千粒重的相关系数受干热风日的土壤墒情、干热风持续天数、干热风出现时期以及冬小麦品种因素的影响,经处理的重度干热风天数与相对千粒重相关显著(P<0.01);建立的相对千粒重回归模型,拟合准确率93.1%,应用准确率95.0%,可以满足农业气象业务服务需求。     

基于标准化降水指数SPI的泾惠渠灌区干旱演变对冬小麦气候产量的影响

为了研究干旱变化对于作物产量的影响机制,以泾惠渠灌区为例,选用标准化降水指数SPI作为干旱评判指标,采用Mann-Kendall趋势检验、最大熵谱分析等方法分析了灌区干旱的变化特征,以及干旱演变下冬小麦气候产量的变化规律。研究表明:(1)灌区冬小麦实际产量呈显著增加趋势(Z=7.6482),气候产量呈不明显减少趋势(Z=-0.5686);(2)灌区总体干旱化趋势明显(通过了99%的显著性检验),这种趋势在春、夏、秋三季都达到了显著水平;(3)干旱存在16 a的年代际周期波动,4~5 a的年际周期;(4)播种前7—9月份和播种后的10、11月的干旱情况对于冬小麦气候产量的影响最大,是影响作物气候产量的关键期;(5)SPI3-9与冬小麦气候产量关系最密切,可以解释46.21%的产量变异;(6)随着干旱的年代际周期变化,SPI3-9与冬小麦气候产量之间的相关系数从0.44上升至0.74,干旱对于冬小麦气候产量的影响有增强的趋势。     

局部灌水方式对冬小麦产量与水分利用的影响

以根系对土壤水分的吸收利用规律、土壤养分在土层中的分布规律和农田土壤蒸发特征为基础,研究局部不同节水高产灌水方式,是解决水肥异位问题和实现“浇作物”的新尝试。2000～2002年连续两年的试验结果表明,测坑内灌溉5水的处理与筒栽灌溉7水的处理有最高的产量和千粒重,适宜的灌水量是30mm。提高作物产量和水分利用效率的灌溉方式应该是灌水集中在作物主要根系分布层,实施高频局部灌溉。     

Visual disease and PCR assessment of stem base diseases in winter wheat

Stem base disease (eyespot, sharp eyespot and brown foot rot) was assessed visually and by the polymerase chain reaction (PCR) technique on single plants sampled at four-week intervals in two crops of winter wheat grown in the UK in 1992–3. PCR assays were conducted for Fusarium avenaceum , F. culmorum , both varieties of Microdochium nivale , both eyespot-causing species of Tapesia and Rhizoctonia cerealis . PCR diagnoses were compared with visual diagnoses at each time point. Eyespot was caused principally by T. acuformis (R-type) and developed rapidly late in the season. Visual diagnoses of eyespot were largely confirmed by PCR but T. acuformis was detected in many plants lacking eyespot symptoms. R. cerealis was detected at relatively low incidences on both sites, and sharp eyespot visual diagnoses did not correlate with the incidence of any of the pathogens assayed by PCR. Brown foot rot, caused principally by Microdochium nivale var . majus , accumulated earlier in the season than eyespot. Overall, visual diagnoses of stem base disease coincided poorly with PCR data until after growth stage (GS) 30.     

喷灌和地面灌溉条件下冬小麦的生长过程差异分析

采用作物生长分析的方法,研究了喷灌和地面灌溉条件下冬小麦生长动态的变化规律。结果表明:与对照地面灌溉相比,在分蘖~抽穗期,喷灌条件下冬小麦的生物产量较小,抽穗后,喷灌有利于植株对干物质的积累,成熟时其生物产量比地面灌溉条件下高8.9%;在分蘖~拔节期,净同化率较低,孕穗~成熟期比地面灌溉高15.7%~30.9%;从第一次灌水处理至成熟,群体生长率平均比地面灌溉高10.1%;在生长前期(分蘖~孕穗期)叶面积指数增长较慢,在生长后期(抽穗~成熟期)叶面积指数衰减率低,从而使生长后期的叶面积持续时间比地面灌溉高15.5d。综上所述,喷灌对冬小麦群体生长的影响具有前控后促的特点,其生长优势主要表现在生长后期。考种结果显示,喷灌条件下冬小麦的结实率、千粒重、产量分别较地面灌溉提高了5.9%、2.8%、11.3%,二者差异显著。     

Variation for resistance to kernel infection and toxin accumulation in winter wheat infected with Fusarium graminearum

Host resistance is the main way to control Fusarium head blight (FHB) in wheat. Despite improved levels of resistance to infection and spread in vegetative tissue, the toxin deoxynivalenol (DON) can still accumulate to unacceptable concentration levels. In this study, our objectives were to assess the genetic variation for resistance to kernel infection (RKI) and resistance to toxin accumulation (RTA) and their role in controlling DON. We collected spikes with different levels of visual symptoms from each of 32 wheat genotypes and at four environments and determined DON and fungal biomass (FB) from each sample. We assessed RKI by regressing FB on the level of visual symptoms and RTA by regressing DON on FB for each genotype. Significant genetic effects were found for RKI and RTA. Some genotypes consistently had low FB in their grain despite increasing visual symptoms suggesting RKI. Additionally, some genotypes consistently had low DON in their grain despite increasing FB levels suggesting a higher RTA in these genotypes. The variation for RKI and RTA explained a significant fraction of the variation for DON among genotypes with moderate visual symptoms using independent grain samples. Although RKI and RTA were significantly correlated (r = 0.58, P = 0.05), RTA was more predictive of DON accumulation because it modeled 32 to 44% of the genotype sum of squares for DON, while only 9 to 10% were predicted using RKI. Thus, variation for RTA was important in explaining variation for DON among genotypes with acceptable levels of resistance to fungal infection and spread. This work indicates that there is a need to develop a better understanding of RTA and rapid screening methods for this trait.     

啶磺草胺WG防除冬小麦田杂草的效果及安全性

7.5%啶磺草胺WG(优先)在冬小麦田使用,对禾本科及阔叶杂草的防效达97%以上,杀草谱广,对恶性杂草早熟禾及菵草防效特好。啶磺草胺以冬前使用最好。用药后10~15 d出现蹲苗现象,20~30 d可恢复正常生长,不影响产量。啶磺草胺冬用及春用对后茬直播水稻无异常影响。     

Surveys of cereal diseases and pests in the Netherlands. 2. Stem-base diseases of winter wheat

In the period 1974–1986, ca. 100 commercial winter wheat fields were surveyed annually for stembase diseases. In these years, on average 6% of the tillers was infected with eyespot in spring at the first-second, node stage. Eyespot intensity in spring was high in years with high temperature during winter. Eyespot, intensity in the milky-ripe stage in July, averaged 13% of the culms and was high in years with high temperature in April and high precipitation in March, April and May. These data may improve forecasts.In the milky-ripe stage, 2% of the culms were infected with sharp eyespot, but its intensity has gradually increased during the survey years. No significant correlation of sharp eyespot intensity with dry periods in autumn, spring or summer was found.Symptoms of take-all were found on 0.2% of the stem-bases during ripening. Its intensity was low in years with high precipitation in March, April, May and June and high temperature in May and June.Samenvatting Een honderdtal percelen wintertarwe werd in 1974–86 jaarlijks op voetziekten geïnventariseerd. In het voorjaar, tijdens het, eerste en tweede knoopstadium van het gewas, was gemiddeld 6% van de spruiten aangetast door oogvlekkenziekte. De intensiteit van de ziekte was hoog in jaren met een hoge gemiddelde wintertemperatuur. Tijdens het melkrijpe stadium, in juli was gemiddeld 13% van de halmen aangetast door oogvlekkenziekte. De aantasting in juli was hoog in jaren met een hoge temperatuur in april en veel neerslag in de maanden maart, april en mei. Met deze gegevens kunnen adviessystemen worden verbeterd.Scherpe oogvlekkenziekte was op gemiddeld 2% van de halmen in juli aanwezig. De ziekte nam geleidelijk met de jaren toe. De jaarlijkse intensiteit was niet gecorreleerd met droge perioden in de herfst, voorjaar of zomer.Symptomen van halmdoder waren op gemiddeld 0.2% van de halmen aanwezig. De intensiteit van de ziekte was hoog in jaren met weinig neerslag in maart, april, mei en juni en met een lage temperatuur in mei en juni.     

陇东黄土高原冬小麦生产农业气象要素分析

对陇东黄土高原半湿润半干旱气候区旱地冬小麦生长期光、热、水三要素与产量进行了相关分析,得出对冬小麦产量起决定作用的农业气象要素为:孕穗—成熟期光照时数,≥0℃积温,开春土壤含水量 返青—孕穗期降水量(R2 3H)。建立了逐步回归方程,Y=-317.138 0.6317X1 0.4647X2。     

The effects of postplanting environment on the incidence of soilborne viral diseases in winter cereals

ABSTRACT Soilborne wheat mosaic virus (SBWMV) and Wheat spindle streak mosaic virus (WSSMV) are putatively transmitted to small grains by the obligate parasite Polymyxa graminis, but little is known about environmental requirements for transmission and the resulting disease incidence. We planted susceptible wheat and triticale cultivars in field nurseries on different autumn dates in 3 years and observed the incidence of symptomatic plants in each following spring. Autumn postplanting environment explained most of the variation in disease caused by both viruses. Little apparent transmission, based on eventual symptom development, of either virus occurred after the average soil temperature dropped below 7 degrees C for the remainder of the winter. To forecast disease, we tested an SBWMV transmission model in the field, based on laboratory results, that predicts opportunities for transmission based on soil temperature and soil moisture being simultaneously conducive. This model was predictive of soilborne wheat mosaic in 2 of 3 years. Zoospores of P. graminis have optimal activity at temperatures similar to those in the SBWMV transmission model. Furthermore, the matric potential threshold (as it relates to waterfilled pore sizes) in the SBWMV transmission model fits well with P. graminis as vector given the size restrictions of P. graminis zoospores. Conditions optimal for SBWMV transmission in the laboratory were not conducive for WSSMV transmission in the laboratory or for wheat spindle streak mosaic development in the field. This differential response to environment after emergence, as indicated by disease symptoms, may be due to virus-specific environmental conditions required to establish systemic infection via the same vector. Alternatively, the differential response may have been due to the involvement of a different vector in our WSSMV nursery than in our SBWMV nursery. Our results suggest that, as a control tactic for SBWMV or WSSMV, earliness or lateness of planting is less important in determining virus transmission and disease than the specific postplanting environment. Improved models based on the postplanting environment might predict virus-induced losses of yield potential, and in some cases, growers might avoid purchase of spring inputs such as pesticides and fertilizer for fields with greatly reduced yield potential.     

1981—2009年新疆小麦和玉米物候期与气候条件变化研究

选取新疆地区1981—2009年17个农业气象观测站的作物(包括春小麦、冬小麦、春玉米和夏玉米)物候资料,利用统计方法分析了作物物候和各生长阶段气候条件的变化趋势。结果表明,春小麦播种、抽穗和成熟期分别提前2.0、3.2和3.3 d·10a~(-1);冬小麦播种期平均推迟1.2 d·10a~(-1),而抽穗和成熟期分别提前4.7 d·10a~(-1)和2.8 d·10a~(-1);春玉米和夏玉米物候期主要呈提前趋势,其中夏玉米播种期平均提前达11.0 d·10a~(-1)。物候的提前或推迟一定程度上导致作物各生长阶段历时发生改变。分析发现新疆地区春小麦营养生长阶段(播种—抽穗)平均缩短1.2 d·10a~(-1),而生殖生长阶段(抽穗—成熟)平均仅缩短0.1 d·10a~(-1)。冬小麦营养生长阶段与生殖生长阶段呈相反的变化趋势,营养生长阶段平均缩短达5.9 d·10a~(-1),而生殖生长阶段却平均延长了1.9 d·10a~(-1),导致整个生育期平均缩短4.0 d·10a~(-1)。春玉米和夏玉米各生长阶段主要呈延长趋势,春玉米营养生长阶段、生殖生长阶段和整个生长阶段分别平均延长0.8 d·10a~(-1)、1.5 d·10a~(-1)和2.3 d·10a~(-1);夏玉米3个生长阶段分别平均延长7.2d·10a~(-1)、1.2 d·10a~(-1)和8.3 d·10a~(-1)。分析研究区1981—2009年不同作物类型各生长阶段气候因子的变化趋势结果表明,大部分研究站点,作物各生长阶段最高温度和最低温度均呈增加趋势,同时其生殖生长阶段的日温差主要呈降低趋势。分析降水变化趋势表明,除春小麦和春玉米生殖生长阶段降水呈增加趋势外,大部分研究站点降水变化趋势不明显。     

Field assessment of the effects of deltamethrin on polyphagous predators in winter wheat

In the south-west of England, cereal aphids can spread barley yellow dwarf virus and reproduce during winter. Ground-living polyphagous predators may be important in controlling these active cereal aphids. This 2-year study investigated the effect of deltamethrin on predator numbers, using pitfall traps. A randomised block design was used in an area of winter wheat (cv. Aquilla) in which deltamethrin-treated and control plots were surrounded by polyethylene barriers. Pitfall catches of polyphagous predators were reduced by about 30% in the treated plots compared with the control plots.     

关中地区不同营养状况冬小麦光谱特性初探

通过田间试验、室内分析测试,系统研究不同N、P水平冬小麦叶片的反射率、叶绿素含量,及其相互关系。结果表明:①施氮增加冬小麦叶片叶绿素作用明显,磷肥对叶绿素含量的影响不明显;②在可见光波段,随施氮量增加反射率下降,在近红外波段则相反。不同施磷水平下反射率差异不明显;③N4营养条件下可见光波段反射率拔节期<灌浆期<抽穗期,P2营养条件下可见光波段反射率灌浆期<拔节期<抽穗期;④叶绿素含量与反射率之间在施用氮肥时显著相关,在施用磷肥时其相关不显著。     

不同土壤水分处理对冬小麦根冠生长的影响

通过温室冬小麦不同水分处理(土壤含水量分别为田间持水量的75%～100%,65%～55%,35%～45%)盆栽试验,研究了冬小麦根冠对水分的响应。试验结果表明:不同供水量并不影响冬小麦根系、冠层干物质累积过程的总趋势,但随胁迫的增强,根、冠干物质累积速率、干物质累积总量降低,且二者并不呈线性相关关系;根冠比(R/S)随胁迫的增强而增大;水分供应量的减少缩短了冬小麦的生育周期,随胁迫的增强,根冠生物量最大值出现的时间提前;充分供水的处理则有最大的根冠比(R/S)。这可能是由于水分胁迫发生,大量的同化产物运往根系,分配于根系的同化干物质增加,调整了根系的结构,改善其功能以增大水分的吸收量,缓减植株由于缺水造成的损失,导致根系干重增加,根冠比增加。对于供水超过75%的植株,根冠比达到所有处理的最大,可能原因为过量水分促使庞大根系的建成,从而消耗较多的同化产物,使根重增加,冠重减少。     

填闲作物腐解过程及其对后茬冬小麦产量的影响

研究了渭北旱塬地区不同填闲作物（长武怀豆（S）、黑麦草（R）及两者1∶1混合（M））翻压和氮肥水平（0、60、120 kg N·hm^-2）双因素处理下,填闲作物的腐解规律、碳氮释放动态及对后茬冬小麦产量的影响,并对腐解速率与Olsen模型进行了拟合。结果表明：各填闲作物翻压后腐解规律及碳氮释放特征均表现为“前期快-中期慢-后期加快”,填闲作物腐解规律符合Olsen模型,在第276天各处理累积腐解率均达70%以上。在第0~35天,同一施氮处理下,累积腐解率和腐解速率均表现为S>M>R（P<0.05）;第35天,S、M和R各处理干物质累积腐解率分别达到61.9%、55.5%和47.5%;在0~35 d,施氮对S、M的腐解影响不显著,对R影响显著,35 d后氮肥效应逐渐减弱;填闲作物的腐解同时伴随其碳、氮的快速释放,在第21天,S、M和R碳氮残留率分别达到40%、50%和60%左右。平均来看,S的碳氮释放速率显著高于R,与M无显著差异。与裸地对照相比,翻压填闲作物能够显著提高后茬冬小麦产量,其籽粒产量增加10%~35% （P<0.05）,其中翻压长武怀豆低氮处理和混合翻压低氮处理效果最佳。