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1.
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 总被引：7，自引：0，他引：7
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。 相似文献
2.
野燕麦在内蒙古察右中旗年发生面积达２．６７万hm２左右，是影响小麦产量的重要因素之一。为了进一步了解野燕麦不同发生密度下对小麦产量的影响，为制定防除指标及防除措施提供科学依据，笔者进行了野燕麦不同密度对小麦产量影响的试验。１试验设计及方法１．１试验地点试验在察右中旗三道沟乡口子村和广昌隆乡东油房村进行。试验田土地平整、肥力均匀，历年野燕麦发生严重，密度高达５００株／m２以上。１．２试验设计于野燕麦苗期（小麦三叶至拔节前）人为控制野燕麦密度，拔除多余的野燕密度５０株／m２，③１００株／m２，④１５０株… 相似文献
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4.
野燕麦在本地区水稻田中能够越夏。田间野燕麦的发生消长呈秋季单峰型，拔节以前生长速率较慢，但拔节后生长发育加快，抽穗期株高、单株叶面积和干物重分别是扬麦５号的１．７５、１．５９和１．２８倍；一般草害田杂草与小麦共生至拔节初期，严重草害田共生至返青期即达到竞争临界期。苗期野燕麦发生量与小麦产量的关系式为ｙ＝２８１．１５－７．３５ｘ（ｒ＝０．９４４，Ｓｙ·ｘ＝１．４２）；针对野燕麦不同发生地区，实行植物检疫、人工除草、农业措施、化学防除等综防配套技术，每亩可增产小麦２５千克以上，显著提高劳动生产率。 相似文献
5.
野燕麦（AvenafatuaL．）是世界性的难治草害之一。野燕麦适应性强，繁殖量大，难于防除，很容易蔓延成灾，对小麦生产造成严重威胁。１野燕麦在冬小麦田的发生特点１）出苗期长。冬小麦田野燕麦出苗有２个主要时期：一是秋季出苗期，主要在小麦播种之后，于１０月中旬至１１月，形成冬前出苗高峰；二是翌年２月下旬至３月，仍有部分出苗。在正常年份秋季出苗数量约占全年总发生量的９０％，春季出苗数量约１０％。在秋季干旱的情况下，野燕麦的出苗量偏低，约占８０％。若春季雨水较多，野燕麦的出苗量可达２０％左右。野燕麦出苗参差不齐… 相似文献
6.
采用二次回归最优设计，研究苏云金素对东亚小花蝽捕食作用的影响，得出日均捕食量（ｙ）与猎物（ｘ１）和捕食者（ｘ２）之产作关系模型。处理捕食数量回归方程：ｙ＝－０＼００２１ｘ１＾２＋１．２１１ｘ２＾２＋０．８８２２ｘ１－１０，３４６５ｘ２－０．０６４９ｘ１ｘ２＋１．７１７４；对照捕食数量回归方程：ｙ＝－０．００１７ｘ１＾２＋０．７７３４ｘ２＾２＋０．６９４１ｘ１－６．４９１４ｘ２－０．０４７４ｘ１ｘ２ 相似文献
7.
磁化水浸种对旱地冬小麦生长发育和产量的影响 总被引：2，自引：0，他引：2
应用不同场强的的磁化水浸种两种小麦２，年田间栽培试验结果表明，磁化水浸种使小麦种子发芽势，一级分蘖数，次生根数，株高，小区有效穗数，穗粒数，千粒重和产量分别提高了１２．２％，１３．７％，７０．３％，７．３％，１０．２％，１７．１％，４．３％和２４．４％，使生育期提前１ｄ－４ｄ。干旱严重的１９９４－１９９５年度增产幅度显著高于干旱较重的１９９５－１９９６年度，两种小麦所需的最佳磁场强度不同。 相似文献
8.
采用二次回归最优设计，研究苏云金素对东亚小花蝽捕食作用的影响，得出日均捕食量（ｙ）与猎物（ｘ１）和捕食者（ｘ２）之间互作关系模型。处理捕食数量回归方程：ｙ＝－０．００２１ｘ２１＋１．２１１２ｘ２２＋０．８８２２ｘ１－１０．３４６５ｘ２－０．０６４９ｘ１ｘ２＋１．７１７４；对照捕食数量回归方程：ｙ＝－０．００１７ｘ２１＋０．７７３４ｘ２２＋０．６９４１ｘ１－６．４９１４ｘ２－０．０４７４ｘ１ｘ２－０．４６３６。综合定性分析和定量分析结果，苏云金素处理东亚小花蝽若虫，减弱了其对二斑叶螨卵的捕食能力，但二者的差异不显著，对种群变化影响不明显 相似文献
9.
稻飞虱（含白背飞虱与褐飞虱）是岑溪县目前发生危害最大的水稻害虫，一年发生８个世代。经１９年的冬后调查说明有本地虫源，其中以白背飞虱为多。早稻秧田虫量与３月上中旬沟边若虫量有一定关联性（ｒ＝０．６７３０）；外地虫源迁入盛期一般在５月中下旬；第三代系主害代，其若虫高峰期与早稻抽穗盛期至灌浆初期相吻合；经十多年调查资料整理筛选出预测第三代高峰期成若虫密度的相关因子：３月上中旬沟边若虫平均密度（ｘ＿１）、３月中下旬秧田成若虫平均密度（ｘ＿２）、５月份降雨量（ｘ＿５）及５月１５～２５日平均成若虫密度（ｘ＿６）、５月份降雨系数（ｘ＿７）等，分别建立、修订预测式：ｙ＝０．１７６ｘ＿１＋０．２２２ｘ＿２＋０．２０３ｘ＿５＋２．３０２（级）……Ⅰ＇、ｙ＝２．５０７＋０．３４０ｘ＿６＋０．１７１ｘ＿１（级）…Ⅱ＇。Ｒ值和Ｆ值均达极显著水平，历史符合率为９４．７％～１００％。 相似文献
10.
野燕麦(Avena fatua.L)是小麦的伴生性杂草.它分布广、繁殖率高,落粒性强,密度大,危害严重,是我地区麦田的恶性杂草.95年对扎兰屯农牧学校麦田调查每平方米有野燕麦10～135株;由于落粒性强,造成下茬的严重草荒.为了探索用除草剂防治小麦田野燕麦尤其是种子田野燕麦的有效方法特进行了如下的试验. 相似文献
11.
N.C.B. PETERS 《Weed Research》1984,24(5):305-315
The growth and competition of wild oats (Avena fatua L.) emerging at different times, and the time of onset of competition by them were studied using natural populations in spring barley. In one experiment in 1972, wild oats emerging in the 0–0?5, 0?5–2?5, 2?5–4 crop leaf stages at densities of 54, 46, 15 m ?2 respectively were allowed to compete all season with the crcp. These gave rise to 82, 17 and l% of all seed shed and caused 16%, and two non-significant yield losses respectively. In two other experiments in 1973, nearly all the wild oats that caused yield losses had emerged by the crop 2˙45 leaf stage. Where wild oats emerging up to the crop 2?5 leaf stage were removed, the later ones did not compensate by making extra growth. In one of these experiments in which densities of crop and weed were 416 and 414 m 2, and in the other where they were 295 and 294 m 2 respectively, grain yield losses were significant if the wild oats remained in the crop until the crop had 2?5–4?5 leaves and 4?5–6?5 leaves respectively. In a third experiment in 1973 with initial densities of 464 wild oats and 336 barley plants m ?2, and where a top dressing of nitrogen was given at the crop 3–4 leaf stage, unlike the other two experiments in 1973 where all nitrogen was applied at sowing, no yield losses resulted unless the wild oats remained in the crop until after the crop 6 leaf stage. 相似文献
12.
Barban was combined with benzoylprop ethyl, flamprop methyl, or flamprop isopropyl, and the eflects of the combinations on wild oat control and crop yield were assessed, tn greenhouse experiments, the interaction in all three combinations was synergistic, following application at the 2- or 4-leaf stage of wild oats. Under field conditions, combinations of barban + benzoylprop ethyl applied at the 2- or 4-leaf stage of wild oats were as eflective for wild oat control and wheat yield response as barban at 028 kg/ha applied at the 2-leaf or benzoylprop ethyl at 14 kg/ha applied at the 4-leaf stage of wild oats. Mixtures of barban + flamprop methyl applied at the 2- or 4-leaf stage of wild oats provided excellent wild oat control and wheat yield increases. Mixtures of barban + flamprop isopropyl applied at the 2- or 4-leaf stage of wild oats provided comparable wild oat control and barley yield increases to barban (028 kg/ha) applied at the 2-leaf or flamprop isopropyl (14 kg/ha) applied at the 4-leaf stage of wild oats. 相似文献
13.
F. FORCELLA 《Weed Research》1987,27(1):31-34
An expérimental procedure was designed to provide a simple model for types of analyses necessary to determine weed density thresholds for advantageous use of crop plants engineered for herbicide resistance. Oilseed rape (Brassica napus L., cv. Tower) biotypes resistant (RES) and susceptible (SUS) to atrazine were used as model crop plants, and wild oat (Avena fatua L.) was used as the model weed. Along a wild oat density gradient equivalent to 0–128 plants m?2, RES plants consistently experienced biomass and yield reductions of approximately 10–20% compared to SUS plants. When atrazine was applied at 1.5 kg ha?1 to control wild oats competing with RES plants, RES biomasses and yields were stabilized at the same level as that where 25–30 wild oats m?2 reduce yields of SUS plants. This implies that with wild oat densities of 25–30 plants m?2, it becomes agronomically advantageous to crop with RES plants plus atrazine rather than to crop with higher-yielding SUS plants. 相似文献
14.
Summary. This project was designed to study various aspects of wild oat competition in spring wheat and flax. From ten to forty wild oat plants/yd2 were sufficient to cause significant yield reductions in wheat when grown on summerfallow land or when ammonium phosphate fertilizer was added to stubble land. However, when wheat was grown on stubble land without the benefit of a fertilizer treatment, seventy to one hundred wild oat plants/yd2 were needed to suppress wheat yields significantly. This would suggest that on stubble land, soil fertility was a more important factor than moderate densities of wild oats in determining eventual crop yields. In these experiments, wild oats reduced the number of tillers per plant, but did not significantly affect the protein content of the harvested grain. Only ten wild oat plants/yd2 were sufficient to reduce flax yields significantly on both summerfallow and stubble land. The only exception was in 1966, when flax grown on summerfallow land was not significantly affected until the density of wild oats reached forty plants/yd2. This confirms the general observation that flax is a poor competitor with wild oats. The results suggest that wild oat competition had already commenced prior to emergence of wheat, particularly with the higher densities of wild oats. In general, competitive effects increased with time and with wild oat density. In flax, severe competition had already taken place prior to the 2–3-Ieaf stage of the weed in 1964, but did not become severe until after the 2–3-leaf stage of wild oat growth in 1965 and 1966. Again, competitive effects increased with time and with wild oat density. Results of a final series of experiments, suggested that the optimum seeding date for flax in Manitoba is the latter part of May or the first week of June. Yield reductions due to wild oat competition became very severe as seeding dates were delayed. La compétition de la folle avoine (A vena fatua L.) avec le blé et le lin 相似文献
15.
JOAN M. THURSTON 《Weed Research》1962,2(3):192-207
Summary. The effect of winter wheat, winter rye, winter barley, spring barley, and fallow cultivated as for a winter cereal, on germination and growth of wild oats ( A. fatua ) was investigated on a naturally-infested field. Treatments were continued for 2 years on the same plots and in the third year all plots were cropped with spring barley. Wild oats were not allowed to shed seeds.
A. fatua was controlled by a dense crop of an autumn-sown cereal. The crop genus was unimportant provided it grew well on the site; its effectiveness depended on its density when the wild oats germinated in spring. Winter wheat and winter rye were equally effective. Even in a light crop of barley, wild oats grew much less vigorously than on the fallow plots. Beyond a certain crop density dependent on soil fertility, further increase in crop did not decrease the size of wild oats. The heaviest crop did not completely suppress the wild oats.
The crop affected the wild oats mainly by decreasing growth of the seedlings, but under winter wheat and winter rye some wild oat seeds may have remained dormant, germinating in the spring barley in the third year, perhaps because the crops decreased the soil moisture content. Nitrogenous fertilizer increased the weight of both crops and wild oats. Barley was more severely affected by soil acidity than wild oats and on acid areas of barley plots the wild oats were larger than where the pH was higher. In wheat and rye which were scarcely affected by soil acidity the size of the wild oat plants was unaffected by soil pH.
L'effet du competition des céréales sur la germination et le développement d' Avena fatua dans un champ naturellement infesté . 相似文献
A. fatua was controlled by a dense crop of an autumn-sown cereal. The crop genus was unimportant provided it grew well on the site; its effectiveness depended on its density when the wild oats germinated in spring. Winter wheat and winter rye were equally effective. Even in a light crop of barley, wild oats grew much less vigorously than on the fallow plots. Beyond a certain crop density dependent on soil fertility, further increase in crop did not decrease the size of wild oats. The heaviest crop did not completely suppress the wild oats.
The crop affected the wild oats mainly by decreasing growth of the seedlings, but under winter wheat and winter rye some wild oat seeds may have remained dormant, germinating in the spring barley in the third year, perhaps because the crops decreased the soil moisture content. Nitrogenous fertilizer increased the weight of both crops and wild oats. Barley was more severely affected by soil acidity than wild oats and on acid areas of barley plots the wild oats were larger than where the pH was higher. In wheat and rye which were scarcely affected by soil acidity the size of the wild oat plants was unaffected by soil pH.
L'effet du competition des céréales sur la germination et le développement d' Avena fatua dans un champ naturellement infesté . 相似文献
16.
The recent characterization of triallate-resistant lines of wild oat (Avena fatua L.) deficient in triallate sulfoxidation provides an experimental system to investigate and differentiate the effects of triallate and triallate sulfoxide on wax and lipid biosynthesis. Greenhouse applications of triallate dramatically reduced epicuticular wax deposition in susceptible (S) but not resistant (R) wild oats. Triallate treatment had no effect on in-vivo concentrations of C12 to C26 fatty acids and fatty alcohols in R plants, while elongated fatty acid fractions (C>18) were significantly reduced in S plants. In contrast, treatment with triallate sulfoxide reduced in-vivo concentrations of elongated fatty acids equally in R and S, supporting the hypothesis that triallate sulfoxide is more inhibitory than triallate towards fatty acid elongases. Although de-novo synthesis of short-chain fatty acids was not affected by triallate or triallate sulfoxide in R or S plants, synthesis of elongated fatty acid fractions was dramatically reduced in S plants by triallate. Fatty acid biosynthesis in R and S plants was equally sensitive to triallate sulfoxide. The results support the idea that in-vivo triallate sulfoxidation is necessary for herbicidal activity, and confirm that reduced rates of triallate sulfoxidation confer resistance in R wild oats. © 1997 SCI. 相似文献
17.
钾锰配施对旱地冬小麦品质和产量的影响 总被引：6，自引：0，他引：6
在豫西褐土区研究了钾锰配施对旱地冬小麦品质和产量的影响。结果表明:钾锰配施、小麦湿面筋含量、沉降值、稳定时间、蛋白质含量及蛋白质产量均有不同程度增加。通过对上述小麦品质指标的方差分析表明,不同施钾水平的差异达到了极显著水平,不同施锰水平除蛋白质产量外均未达到显著水平。钾(x1)锰(x2)配施小麦产量的回归模型为:y=3471.6879 12.4313x1 318495x2 49.3548x1x2-0.0648x12-75075000x22,最高产量施肥量为基施96.7kg/hm2K2O的基础上,配合喷施质量百分比浓度为0.2%的硫酸锰。 相似文献
18.
The competitive interactions between Avena sterilis ssp. ludoviciana (Dur.) Nyman and winter barley have been studied, taking into consideration the densities of both species. As the density of A. sterilis increased, barley yield decreased exponentially. A 10% reduction in yield was found with wild oat densities ranging from 20–80 panicles m–2, and yield losses reached 50%, with densities of >300 panicles m–2, Barley grain yield was reduced by wild oats through a reduction in the number of fertile tillers. Climatic conditions during the growing seasons affected the response of barley to wild oat competition. In general, barley yields were relatively unaffected by seeding rates, with similar responses observed in the presence and in the absence of wild oat infestations. However, the highest yield losses were obtained with the lowest seeding rate (100 kg ha–1). Furthermore, low barley densities allowed the wild oat plants to produce more seeds, increasing the potential infestation during the following season. 相似文献
19.
干旱胁迫下CoCl2对紫花苜蓿幼苗生长影响初探 总被引：1，自引：0，他引：1
通过不同浓度的CoCl2溶液浸种,研究在干旱胁迫下促进紫花苜蓿幼苗生长的最佳浓度。试验结果表明:在干旱胁迫下CoCl2处理的紫花苜蓿幼苗,以0.00025～0.1mmol/L处理的幼苗在株高、分枝数、根系长度、叶面积、地上部分鲜重、地下部分鲜重、地上部分干重、地下部分干重都有所增加,浓度为0.005mmol/L时各指标基本表现为最优。研究表明,较低浓度的CoCl2具有保护幼苗的作用,较高浓度时则表现为一定的伤害作用。紫花苜蓿株高(y)与叶面积(x1)、分枝数(x2)、地下部分鲜重(x3)、地上部分干重(x4)、根系长度(x5)、地上部分鲜重(x6)、地下部分干重(x7)之间的多元线性回归方程为:y=2.9153-0.4377x1 0.1227x2-4.9510x3-3.0736x4 226.4584x5 350.9114x6 342.4854x7。 相似文献