野芥菜田间发生量与小麦产量损失关系的初步研究

野芥菜(Brassica juncea(L)Cyern et Coss),俗称野油菜,是我省农田主要杂草,分布广,发生密度大,株高叶大,与小麦等作物有强烈的竞争性,危害大。据调查,野芥菜在全省农田出现频度为27.14％,草情指数为6.67,危害率4.11％。研究野芥菜田间发生量对小麦产量损失的关系,     

硬草发生量与小麦产量损失的关系

近年来,硬草在我省沿海地区发生越来越为严重,已成为该地区稻茬麦田的主要恶性杂草,它发生密度大,分布广,与小麦、油菜等作物具有强烈的竞争能力。为此,我们于1990年对硬草发生量与小麦产量的损失进行了初步研究。一、试验方法试验设在响水县黄淮海开发实验区小麦百亩方。4月20日用5点法测查了田间的硬草发生密度,每点0.1米~2。在小麦成熟后选取15块硬草不同发生量的田块进行测产,并对结果进行统计分析。二、试验结果 (一)硬草发生量对小麦产量的损失田间硬草的发生量对小麦产量有极显著的影响,相关系数r=-0.8516~(**),回归方程     

野燕麦与小麦竞争对产量的影响

野燕麦(Avena fatua L.)原是我国北方春小麦及旱作冬小麦田的主要恶性杂草。但近几年来,野燕麦在本县稻麦两熟地区的发生逐渐加重,现已开始成为麦田新的杂草优势种群。为此,1990～1992年我们采用系统测定和大田抽样调查的方法,进行了野燕麦与小麦之间的竞争力及其危害损失率测定的初步研究。一、内容与方法 (一) 野燕麦与小麦竞争力观察系统观察田分别设在泰县苏陈镇双河村和鲍徐镇新建村,在小麦主要生育阶段,分别取杂草和麦苗各20株,考察其株高、单株叶面积和干物重。 (二) 野燕麦发生量与小麦产量损失的关系     

野燕麦、遏兰菜复合群体对小麦产量损失研究

试验采用二因素五水平二次回归通用旋转组合设计，研究野燕麦遏兰菜不同密度的复合群体与小麦减产率，穗数减少率，穗粒数减少率等指标函数间的变化规律。结果表明，野燕麦密度是影响产量的主要因子，遏兰菜密度是次要因子。野燕麦，遏兰菜密度与小麦减产率，穗数减少率，穗粒数减少率在试验范围内呈正相关关系，小麦减产率回归方程为：Ｙｙ＝２０．７０＋６．０９１３ｘ１＋２．１５６３ｘ２＋４．３２５０ｘ１ｘ２－２．１３５５ｘ     

野燕麦田间发生密度对小麦、青稞产量损失估测及防除策略的研究

杂草对农作物有很大危害是众所周知的,确切知道不同情况下的草害程度对防治对策有现实的指导意义。目前各地都在进行这方面的试验,方法和准确性也异。本文介绍了野燕麦对小麦、青稞在青海省条件下的危害,其方法可供各地参考。同时对试验中所应用的数理统计是否合宜,也可供讨论。1.田间野燕麦发生密度对小麦、青稞产量损失之间有着极显著的回归关系。野燕麦穗数即花序数每增加1万穗/亩,小麦产量损失5.39斤、穗粒数减少0.15粒、千粒重降低0.102克,青稞产量损失3.5斤、穗粒数减少0.17粒、千粒重降低0.02克。2.小麦三叶期以前田间出苗的野燕麦危害最大,在野燕麦10万株/亩左右密度下,减产35.5%;小麦开始拔节以后出苗的野燕麦危害较小,造成减产8%以下。3.田间野燕麦密度越大,后期复盖阴闭越严重。野燕麦株数每亩16万株以上,复盖度90%以上,并导致小麦倒伏。4.据野燕麦危害损失,结合当前生产水平,对野燕麦发生的轻度危害田、中等危害田、严重危害田、控制田的划分指标和防除策略进行了探讨。     

小麦赤霉病与产量损失

1978年冬至1979年春,我们在小麦赤霉病严重发生的永春县农场进行此项研究。 当年病情相当严重。从试验区里选择发病中等的晋系麦84081品种,病情指数为49.96,随机取样305穗进行详细剖析。先把它按严重度分级标准分成各个严重度的级。     

南京市区野燕麦防除试验

1982～1984年,先后应用阿畏达(即燕麦畏,又名野麦畏)、禾草灵、燕麦敌1号和2号、绿麦隆等10种除草剂进行了野燕麦的防除试验,结果以阿畏达、禾草灵和燕麦敌一号防除效果较好。对40%阿畏达和36%禾草灵进行了不同剂量的试验,前者用量每亩0.1斤、0.15斤、0.2斤和0.25斤,防效分别为88.3%、94.9%、95.8%和99.1%,后者用量每亩0.1斤、0.2斤、0.3斤和0.4斤,防效分别为95.6%、99.6%、100%和100%。     

油菜田防除野燕麦试验

野燕麦(Avena fatua L.)近年来E成为我区油菜和小麦田的恶性伴生杂草,发生危害面积占种植面积的48.7％,田间密度达15—300万株/亩,每年粮油作物产量损失在1千万公斤以上。为此,1985—1986年在油菜田进行化学防除野燕麦试验,结果简报如下: 试验区设在土地平坦、肥力一致、野燕麦发生严重分布均匀的伊犁黄油菜田。栽培管理与大田相同。小区面积15m~2,随机排列,重复3次(对照重复6次)。结果见表。试验结果经方差分析,区组间差异不明显,     

野燕麦的危害损失及防除指标研究

野燕麦的危害损失及防除指标研究许浩然，许莉（新疆沙湾县农业技术推广中心８３２１００）野燕麦（ＡｖｅｎａｆａｔｕＬ）是农田中的恶性杂草。沙湾县小麦田发生面积２６６７ｈｍ２，占小麦面积的２０％以上，每年小麦产量直接损失２２５０ｔ。为了揭示野燕麦不同密度对...     

青海燕麦畏防除野燕麦药效试验总结（摘要）

为解决野燕麦草害问题,自60年代初就进行防除研究,对上百种除草剂进行了试验比较,确定燕麦畏是防除野燕麦的一种好的除草剂,具有明显的优越性。第一,灭草效果高,可稳定在95％左右,比人工除草三次都好;第二,对小麦、青稞等多种作物安全,小麦药害一般在1％以下;防除后小麦增产一般在30％以上;第三,使用剂量低,药价较廉,每亩约2元,防除后的经济效益达1∶10;第四,使用期长,比较灵活,可作播前处理,亦可作秋季施药,还可在三叶期结合灌水施药,使用方法简便。近年,青海、甘肃、西藏、陕西、黑龙江、新疆等省(区)已开始大面积使用,总面积达350万亩,深受农民欢迎。但是,这些农药都是从美国进口,需要花费巨额外汇,有时还不能及时到货,影响农业生产的使用。     

The role of coleoptile on barban sensitivity between wild oat and wheat

Differential sensitivity of wild oat (Avena fatua L.) and wheat (Triticum aestivum L.) to barban (4-chloro-2-butynyl-m-chlorocarbanilate) was highest when barban was applied to the coleoptile. The coleoptile acts as a physical and physiological barrier to reduce the concentration of free barban in the stem section where the sensitive meristematic sites are located. Metabolism of barban was higher ïn the coleoptile of tolerant wheat than in that of susceptible wild oat. Free barban concentration was higher in the stem of wild oat than in the stem of wheat after 24 hr, but after 48 hr, concentrations were similar. The coleoptile appears to enhance the differential sensitivity to barban between wild oat and wheat.     

我国小麦产区间病害发生与损失差异比较研究

为系统全面地掌握我国各产区小麦病害的发生情况,本文重点分析了我国小麦五大产区(华东麦区、华中麦区、华北麦区、西北麦区和西南麦区)小麦锈病、赤霉病、白粉病、纹枯病、黑穗病、根腐病和全蚀病的发生及防控情况。结果表明：我国小麦病害发生危害具有区域性特点,华东和华中麦区小麦纹枯病和赤霉病发病面积较大,且造成产量损失占比远超其余三大产区;华北麦区以白粉病发生最重;西北和西南麦区锈病和白粉病发生最重。我国小麦病害防治效果显著,华东和华中麦区赤霉病、纹枯病的年均挽回损失率均在80%以上;华北麦区年均挽回损失率最高的病害是白粉病(84.43%);西北和西南麦区对锈病年均挽回损失率分别为78.20%和85.26%;黑穗病、根腐病和全蚀病挽回损失率较低。     

小麦赤霉病田间病情与病粒率关系探讨

采用病情普查、不同严重度病穗病粒率测定、田间病粒率调查测算及多元回归分析等方法,研究了小麦赤霉病田间病情与病粒率的关系,并建立了由田间病情直接换算病粒率的数学模型,经拟合检验平均误差为0.09个百分点。     

恶唑禾草灵防除春小麦田野燕麦的效果

10%恶唑禾草灵EC防除春小麦田野燕麦试验结果表明,用量900～1 500 ml/hm2,在小麦3～4叶期、野燕麦2～3叶期兑水300 kg/hm2茎叶喷雾,对野燕麦的防除效果达90%以上,对小麦安全.     

Influence of time of emergence of wild oat on competition with wheat

The influence of time of emergence of wild oat (Avena fatua L.) on its competition with wheat (Triticum aestivum L.) was studied, using boxes that allowed separation of root and shoot competition. The relative yield total for mixtures of wild oat and wheat, grown under different forms of competition and with different wild oat sowing times, was very close to unity, indicating that the two species competed fully for limiting resources. Wild oat was more competitive than wheat when the two species were sown simultaneously, due largely to its greater root competitive ability; the two species had similar shoot competitive abilities. When wild oat was sown 3 or 6 weeks later than wheat, wheat was more competitive than wild oat and the production of wild oat panicles was prevented. This was mainly the result of greater root competitive ability of the wheat, although shoot competitive ability was also greater. The effects of root and shoot competition were additive. It is concluded that in order to prevent the return of wild oat seeds to the soil, and hence obtain long-term benefit, it is necessary to control the wild oat seedlings emerging within the first 3 weeks after drilling a wheat crop.     

Influence of take-all epidemics on winter wheat yield formation and yield loss

ABSTRACT The effects of take-all epidemics on winter wheat yield formation were determined, and disease-yield relationships were established to assess the agronomic efficacy and economic benefits of control methods. Epidemics were generated in naturally infested fields by varying cropping season, crop order in the rotation, and experimental fungicide seed treatment. Disease incidence and severity were assessed from tillering to flowering. Yield components were measured at harvest. Models simulating the formation of the yield components in the absence of limiting factors were used to estimate the losses caused by take-all. Losses were predicted by the disease level at a specific time or the area under the disease progress curve, reflecting accumulation during a specific period. Losses of grain number per square meter and 1,000-grain weight were linked to cumulative disease incidence between the beginning of stem elongation and flowering, and disease incidence at midstem elongation, respectively. Yield losses were accounted for by both cumulative disease incidence between sowing and flowering, and disease incidence at midstem elongation. Results confirm the importance of nitrogen fertilization in reducing the impact of take-all on wheat.     

小麦白粉病反应型和产孢量的关系

利用小麦的6个品种及小麦白粉菌的3个小种研究了小麦苗期白粉病反应型与产孢量之间的关系。分别用累积单斑产孢量(LBSY)、累积单位面积产孢量(LASY)与反应型组建了反应型-产孢量关系模型:Y_1=exp(1.7178×lnX 0.0256X-2.484)(LBSY法);Y_2=exp(1.5168×lnX 0.052X-2.309)(LASY法)(X为反应型,Y为产孢系数)。通过LBSY方法获得反应型0,1,2,3~-,3,3~ ,4~-,4所对应的产孢系数分别为0,0.09,0.29,0.49,0.60,0.71,0.96,1。     

小豆产量与主要产量性状关系的研究

应用灰色系统理论对小豆产量与产量性状进行了综合分析。结果表明,小豆产量与主要产量性状的关联度大小依次为：单株粒数、单株荚数、单株粒重、百粒重、单荚粒数和主茎分枝数。     

Competition between vegetative plants of wild oat (Avena fatua L.) and wheat (Triticum aestivum L.)

Competition between wild oat (Avena fatua L.) and wheat (Triticum aestivum L.) was studied in two experiments; a replacement series model and a technique for separation of root and shoot systems. Wild oat and wheat in association resulted in a relative yield total very close to unity showing that the two species were‘crowding for the same space’(or competing for the same resources) and were‘mutually exclusive'. Wild oat was more competitive than wheat, as shown by its aggressivity relative to wheat, relative yields, shoot dry weights and other plant attributes. The greater competitive ability of wild oat was predominantly due to its greater root competitive ability, while the two species had similar shoot competitive ability. Root competition had a much greater effect on the relative performance of the two species than did shoot competition. The effects of root and shoot competition were additive.