湖北省油菜田杂草种类组成及群落特征

采用倒置“Ｗ”取样法对湖北省油菜田的杂草组成及群落结构进行了调查。结果表明,湖北省油菜田杂 草有１３５种（含变种）,隶属于２６科、７４属,其中优势杂草有看麦娘、波斯婆婆纳、棒头草、牛繁缕、?草、猪殃殃、早 熟禾、日本看麦娘等８种,区域性优势杂草有１３种,常见杂草有２６种,一般杂草有８８种。发生优势度较大的杂草 为波斯婆婆纳、看麦娘、棒头草、牛繁缕、?草、猪殃殃和野燕麦等,是构成各地区田间杂草群落的优势种。水旱轮 作油菜田主要形成看麦娘＋?草＋棒头草＋牛繁缕为主的杂草群落,旱旱连作田形成波斯婆婆纳＋野燕麦＋猪殃 殃＋通泉草为主的杂草群落。江汉平原地区油菜田杂草群落的物种丰富度、多样性较其它地区高,而优势度及均 匀度指数较低。从群落相似性来看,武鄂黄地区与水旱轮作田杂草群落结构最为相似。作物种类、耕作制度及土 壤环境条件的不同,可能是导致油菜田杂草发生及群落组成产生差异的原因。     

沿海农业区麦田杂草群落演替及治理策略探讨

建国以来 ,江苏沿海农业区麦田杂草发生种类和优势种群发生了变化 ,实现了从盐生性杂草群落向旱生耐碱性杂草群落、湿生性杂草群落的过渡 ,多年相对稳定的耕作制度 ,出现了以波斯婆婆纳、猪殃殃为优势种的棉套麦田顶级杂草群落 ,以硬草、日本看麦娘为优势种的稻茬麦田顶级杂草群落 ,和以硬草、日本看麦娘、猪殃殃为主体的稻麦旱 (棉、玉米 )麦轮茬麦田的混生顶级杂草群落。麦田杂草治理应本着”科学合理、高效长效和可持续性”为原则 ,以”截流竭库”为手段 ,从而达到“经济环保”的生产目标。     

沿海农业区麦田杂草群落演替及治理策略探讨

建国以来，江苏沿海农业区麦田杂草发生种类和优势种群发生了变化，实现了从盐生性杂草群落向旱生耐碱性杂草群落、湿生性杂草群落的过渡，多年相对稳定的耕作制度，出现了以波斯婆婆纳、猪殃殃为优势种的棉套麦田顶级杂草群落，以硬草、日本看麦娘为优势种的稻茬麦田顶级杂草群落，和以硬草、日本看麦娘、猪殃殃为主体的稻麦旱(棉、玉米)麦轮茬麦田的混生顶级杂草群落。麦田杂草治理应本着”科学合理、高效长效和可持续性”为原则，以”截流竭库”为手段，从而达到“经济环保”的生产目标。     

河南省冬小麦田杂草组成及群落特征

为明确河南省冬小麦田间杂草组成及群落结构,采用倒置"W"型九点取样法对河南省冬小麦田杂草进行了调查。结果表明,河南省冬小麦田杂草共有66种,隶属于22科,57属,其中菊科、禾本科和十字花科杂草种类较多,分别有13、10、9种。优势杂草有猪殃殃、荠菜、播娘蒿、野燕麦、泽漆和波斯婆婆纳共6种;区域性优势杂草有看麦娘、刺儿菜、打碗花、野芥菜、麦瓶草、稻槎菜、繁缕和节节麦共8种。此外还有常见杂草19种和一般性杂草33种。从杂草区域分布来看,河南省6个区域中,豫中南平原区物种丰富度最高,为45种,豫中南平原区和豫西丘陵区的物种多样性最高,而豫北平原区和豫南平原区的Simpson优势度指数最高。经聚类分析,河南省6个区域小麦田杂草群落可分为4组:豫东平原区、豫西南平原区和豫中南平原区杂草群落聚为一组;其他3个区域冬小麦田杂草群落结构各有特点,均自成一组。     

河南省3种麦田阔叶杂草对苯磺隆的抗性

为明确河南省冬麦田3种阔叶杂草猪殃殃、播娘蒿、牛繁缕对苯磺隆的抗性水平和分布现状,在温室中采用整株剂量-反应测定法测定了3种杂草的40个种群对苯磺隆的敏感性。结果表明,河南省3种阔叶杂草已普遍对苯磺隆产生抗性,所测样本中,抗性种群27个,占总采样数的67.50%,其中牛繁缕抗性水平最高,猪殃殃居中,播娘蒿最低。豫中和豫南地区3种杂草的整体抗性水平较高,豫西和豫西南抗性水平相对较低。     

亚麻田和苎麻苗床地化学除草试验及生产应用

南方冬季种植的亚麻,田间主要杂草有看麦娘、牛繁缕.苎麻春季育苗苗床地主要杂草为看麦娘、马唐、牛繁缕.用5%金草克乳油每666.7m2用量45-50ml.在亚麻、苎麻播后45-90天,即杂草3-9片真叶时喷雾,其鲜重防效分别为87.1%和81.5%,对亚麻、苎麻安全无药害.一次用药后能完全控制亚麻全生育期和苎麻育苗期间的草害.     

大麦田无草害工程关键技术及其应用研究

射阳县地处苏北灌溉总渠南岸的沿海地区 ,是全国著名的啤麦生产基地县 ,常年种植大麦 1万 hm2 左右 ,草害每年造成啤麦损失0 .3～ 0 .4万 t,占麦子总产量的 7%～ 9%。为控制草害 ,减轻损失 ,增加效益 ,我站从 1994年开始组织实施大麦田无草害工程 ,1995年通过国家农业部验收 ,5年来取得了显著效果。现将其关键技术及其应用成果报道如下。1　麦田杂草群落及其构成由于三大生态农业环境和耕作制度的差异 ,相应形成了三大杂草群落。1.1　海河稻区杂草群落 :以硬草为主 ,混生猪殃殃、看麦娘、巢菜、棒头草等。1.2　射阳河北农业区杂草群落 :以泽…     

稻油轮作田杂草种子库组成及其垂直分布特征

杂草种子库是潜在的杂草群落，对杂草可持续治理具有重要意义。在稻油轮作田杂草种子库中共检测到28种杂草，主要隶属于禾本科、玄参科和菊科，种子库密度达224 550 seed/m2，其中约64％为冬季油菜田杂草种子。从杂草种子库中种子的垂直分布来看，土壤表层的种子密度较高，占整个种子库数量的63.88%，而中层和下层的种子密度较小，其垂直分布主要有3种类型。种子库中优势恶性杂草有菵草Beckmannia syzigachne、异型莎草Cyperus difformis、看麦娘Alopecurus aequalis、稻槎菜Lapsana apogonoides和日本看麦娘Alopecurus japonicus等，随着土层深度的增加，各土层的优势种组成也有差异。通过采取措施调控杂草种子库的规模，有望实现稻油轮作田杂草的可持续治理。     

湖北省花生主产区花生田杂草种类与群落特征

为了明确湖北省花生主产区花生田杂草的发生危害现状和群落组成特征,运用倒置"W"9点取样对田间杂草群落进行了调查。结果表明,该省花生主产区花生田杂草有76种,隶属于24科,其中优势杂草有4种,局部优势杂草有6种,次要杂草有10种,一般性杂草有56种。相对多度较大的杂草有马唐、鳢肠、火柴头和铁苋菜,是构成湖北花生主产区花生田杂草群落的优势种。鄂东北地区花生田主要形成鳢肠+马唐+火柴头为主的杂草群落,鄂北地区花生田主要形成马唐+铁苋菜+火柴头+鳢肠为主的杂草群落。鄂东北地区花生田杂草群落的物种丰富度、Shannon-Wiener指数、Pielou均匀度指数较高,而Simpson优势度指数较低。     

亚麻田和苎麻苗床地化学除草试验及生产应用

南方冬季种植的亚麻,田间主要杂草有看麦娘、牛繁缕。芝麻春季育苗苗床地主要杂草为看麦娘、马唐、牛繁缕。用5％金草克乳油每666.7m2用量45-50ml。在亚麻、苎麻播后45-90天,即杂草3-9片真叶时喷雾,其鲜重防效分别为87.1％和81.5％,对亚麻、苎麻安全无药害。一次用药后能完全控制亚麻全生育期和苎麻育苗期间的草害。     

黑龙江省北部大豆田杂草调查

采用与传统的五点取样法不同的倒置“Ｗ”９点采样法,对黑龙江省北部豆麦轮作区大豆田杂草发生危害情况进行了调查。结果表明,该地区大豆田杂草有１７科４１种。其中阔叶杂草１４科３５种,占８５．４％,禾本科４种占９．８％,鸭跖草科１种,木贼科１种,种占２．４％。相对多度达１０以上的杂草依次为,稗草、鸭跖草、间荆、铁苋菜、香薷、反枝苋、藜、卷茎蓼、苍耳等９种。其中前７种相对多度达２０以上,可视为当地大豆田的优势杂草。     

不同牧草混播方式对冬闲田杂草发生及种类的影响

为了解冬闲田播种的不同种类牧草田的杂草群落发生动态，调查了30％黑麦草＋70％白三叶，30％黑麦草＋70％紫云英，30％黑麦草＋70％紫花苜蓿，3种不同牧草混播处理下冬闲田杂草的生长特点。结果表明：牧草混播种类的变化使冬闲田杂草的发生有差异，主要表现为杂草种类和危害程度不同，其中以30％黑麦草＋70％紫云英处理下的冬闲田杂草危害程度最低。     

Screening and Future Exploitation of Allelopathic Plants as Alternative Herbicides with Special Reference to Hairy Vetch

Summary

Allelopathic cover crops are one of the most promising application of allelopathy for weed control and reduce the synthetic herbicides input. Fifty three cover crop plant species (26 leguminous, 19 graminaceous and 8 others) were assessed for the allelopathic activity using Plant Box Method. It was found that leguminous cover crops such as hairy vetch (Vicia villosa) and velvetbean (Mucuna pruriens), graminaceous cover crops, such as oat (Avena sativa) and rye (Secale cereale), certain cultivars of wheat (Triticum aestivum) and barley (Hordeum vulgare) were promising. By bioassay screening, 23 species were selected for field tests. Fall-sown cover crops such as hairy vetch, rye, wheat, oat, grass pea, and mustard are more effective when compared to spring-sown cover crops. Hairy vetch was most promising for the weed control in abandoned fields because of its ability to die off during summer season to make a thick straw-like mulch.     

12种除草剂对冬小麦田阔叶杂草的防除效果

为了筛选出对麦田阔叶杂草防效较高的药剂,选择12种目前生产中常用的除草剂进行大田试验。结果表明,施药后15d,对播娘蒿、荠菜、猪殃殃三种杂草总体株数防效最好的是对杂草致死速度快的唑草酮,40%唑草酮水分散粒剂30g(a.i.)·hm-2(指每公顷有效成分用量为30g,其余类推)处理的株数防效达91.78%;施药后30d对三种杂草总体株数防效最好的是55%苯·唑·2甲钠可湿性粉剂412.5g(a.i.)·hm-2处理,株数防效为96.53%,鲜重防效为98.79%;总体株数防效和鲜重防效仅次于55%苯·唑·2甲钠可湿性粉剂处理的分别是58g·L-1双氟·唑嘧胺悬浮剂11.8g(a.i.)·hm-2处理(株数防效为93.59%)、37%炔·苄·唑草酮可湿性粉剂222g(a.i.)·hm-2处理(鲜重防效为98.76%);总体鲜重防效最低的是30%二氯吡啶酸水剂202.5g(a.i.)·hm-2处理(鲜重防效仅为35.29%)。三种杂草对同种药剂的敏感性存在差异。12种除草剂对小麦的安全性有一定差异,唑草酮及其混剂处理后小麦产生的触杀型药害斑及啶磺草胺处理的小麦叶片黄化均可恢复,对小麦的产量无不良影响,其他处理均对小麦安全。     

不同氮肥施用量对东北玉米田杂草发生的影响

利用吉林省梨树县黑土区氮肥长期定位试验田(施氮水平为0、60、120、180、240、300 kg/hm~2),2019～2020两年调查玉米田杂草种类、密度和生物量及其与玉米生物量和产量的关系。结果表明,试验条件下玉米田杂草主要是禾本科杂草,尤其是水稗草Echinochloa oryzoides。与不施肥相比,60 kg/hm~2施氮量增加杂草密度和生物量;随氮肥施用量的增加,杂草的密度和生物量均显著降低。在180 kg/hm~2供氮量时,杂草的密度和生物量达到最低,分别比60 kg/hm~2施氮量的最大值下降81%～94%和90%,玉米产量达到最大。与180 kg/hm~2施氮量相比,进一步增加施氮量,玉米产量不增加,杂草的密度和生物量也不再减少。因此,从施肥经济效益和杂草防控两个方面结合考虑,该地区最优施肥量为180 kg/hm~2。     

Spatial and temporal dynamics of Apera spica-venti seedling populations

Apera spica-venti is an important weed problem in winter cereals in Europe. Spatial and temporal dynamics of A. spica-venti were investigated to test the hypothesis that this species has a spatially aggregated distribution. A. spica-venti distribution was quantified over several crop rotation sequences in three commercial fields. From 1999 to 2006, the spatial pattern of A. spica-venti was sampled yearly at the same grid points. Geostatistical techniques were used to characterise the spatial and temporal variability of A. spica-venti density. The spatial pattern was analysed by Lloyd's index of patchiness. From year to year, differing aggregation of A. spica-venti resulted in weed patchiness. The Spearman Rank Correlation Coefficient (r_s) was used to discover the strength of A. spica-venti occurrence in several years. For two sites there were significant correlations of weed occurrence between years but the relationship was less strong for the third field. Based on rank correlation coefficients, the temporal dynamics were marked by an overall continuity of distribution patterns. Knowing that spatial distributions of weeds vary little in time can reduce sampling efforts, and increases feasibility of site-specific weed control.     

Weed seed bank as affected by crop rotation and disturbance

An experiment was conducted to determine the influence of crop rotations on soil seed bank to provide a comparison between crop fields and non-crop lands. Crop rotations were continuous dryland wheat (Wd), continuous irrigated wheat (Wi), wheat-sugarbeet (WS) and wheat-chickpea (WCh). Nearby pastures (P) and orchards (Or) were also studied for comparison purposes. Estimates of the density of seed banks ranged from 52779 seed m⁻² in P to 9906 seeds m⁻² in Wd. A total of 114 plant species from 24 families were identified from seeds collected from different farms. 33 weed species were at high frequency in weed communities. Crop rotations were dominated by annual weed species, while the weed species dominated in P were mostly not found in any crop rotation. The two weed species Roemeria refracta and Eragrostis cilianensis were frequently present in all the study sites. Amaranthus chlorostachys and Euphorbia esula were more abundant in the areas of moderate to high disturbance. In SW and WS rotations, due to use of grass herbicides and hand weeding, winter annual broadleaves such as Lactuca serriola and Anchusa italica were the prominent species in the seed bank. Results showed that a number of weed species are adapted to a specific crop sequences and disturbance levels. Weed species richness, seed bank abundance and diversity in soil depths are highly dependent on disturbance levels. The current study highlights the importance of agricultural practices including crop sequences or disturbance levels in determining the characteristics of weed populations. This provides useful information to improve methods for maintaining plant population balance.     

A model to simulate yield losses in winter wheat caused by weeds,for use in a weed management decision support system

The ‘within-season’ module of the Weed Manager decision support system (DSS) predicts the effect of twelve UK arable weeds on winter wheat yields and profitability. The model and decision algorithm that underpin the DSS are described and their performance discussed. The model comprises: (i) seedling germination and emergence, (ii) early growth, (iii) phenological development, (iv) herbicide and cultivation effects and (v) crop yield loss. Crop and weed emergence are predicted from the timing and method of cultivation, species biology, and the weather. Wheat and weeds compete for resources, and yield losses are predicted from their relative leaf area at canopy closure. Herbicides and cultural control methods reduce weed green area index, improving crop yield. A decision algorithm identifies economically successful weed management strategies based on model output. The output of the Weed Manager model and decision algorithm was extensively validated by experts, who confirmed the predicted responses to herbicide application were sufficiently accurate for practical use. Limited independent data were also used in the validation. The development of the module required integrating novel and existing approaches for simulating weed seedling establishment, plant development and decision algorithm design. Combining these within Weed Manager created a framework suitable for commercial use.     

多遥感光谱指标结合进行大田冬小麦叶片叶绿素含量估测研究

为解决大田冬小麦叶片叶绿素含量估测模型精度低、通用性弱的问题,在获取冬小麦拔节期和抽穗期冠层红光波段反射率(BR_red)和近红外波段反射率(BR_nir)的基础上,计算归一化差值植被指数(NDVI)、差值植被指数(DVI)、比值植被指数(RVI)、土壤调节植被指数(SAVI)、改进型比值植被指数(MSR)、重归一化植被指数(RDVI)、II型增强植被指数(EVI2)和非线性植被指数(NLI)等8个植被指数。经统计分析,选择与叶片叶绿素含量(SPAD值)相关性较好的5个遥感光谱指标(NDVI、MSR、NLI、BR_red和RVI)作为输入变量,建立了冬小麦叶片叶绿素含量的BP神经网络估测模型(WWLCC_BP),并对估测模型进行精度验证。结果表明,WWLCC_BP估测模型在拔节期估测的决定系数(r²)为0.84,均方根误差(RMSE)为5.39,平均相对误差(ARE)为9.87%。抽穗期的估测效果与拔节期较为一致。将WWLCC_BP和高分六号影像...