辽宁省大豆田杂草发生与危害

采用倒置"W"九点取样法调查辽宁省大豆田杂草,明确了辽宁省大豆田杂草有19科35种,其中阔叶杂草占74.29%,禾本科杂草占14.29%,其他杂草占25.71%;一年生杂草占54.29%,多年生杂草占31.43%。相对多度达10%以上的杂草依次为藜、鸭跖草、稗草、苘麻、反枝苋、红蓼、马唐、铁苋菜、马齿苋和山苦菜。其中藜和鸭跖草相对多度在30%以上,为辽宁省大豆田杂草优势种群。     

辽宁省蔬菜田杂草发生与危害

辽宁省大白菜、芸豆、茄子和辣椒田主要杂草有33种,隶属于17科,其中阔叶杂草占84．88％,禾本科杂草占12．12％,莎草占3％。相对多度达10％以上的杂草依次为马齿苋、马唐、凹头苋、反枝苋、牛膝菊、稗、藜、铁苋菜、香附子,为辽宁省蔬菜田杂草优势种。     

吉林省西北部地区向日葵田杂草调查初报

采用倒置“W”9点取样法,对吉林省西北部地区向日葵田杂草进行了调查.结果表明,该地区向日葵田杂草有19科49种,其中阔叶杂草16科36种占73.5％,禾本科杂草10种占20.4％,其他3种(列当科1种、木贼科2种)占6.1％.一年生杂草35种占71.4％,一年生或越(多)年生杂草3种占6.1％,多年生杂草11种占22.4％.相对多度达10以上的杂草有4科11种,按相对多度由高到低的次序排列,分别为列当、藜、刺藜、反枝苋、稗草、野稷、芦苇、苍耳、狗尾草、苣荬菜、虎尾草,可视为吉林省西北部地区向日葵田的主要杂草.     

山东省泰安市苗圃杂草调查

运用倒置"W"9点取样法,对山东省泰安市苗圃杂草发生与危害情况进行了调查.结果表明,泰安市苗圃杂草有22科50种.其中阔叶杂草31种,占62%,禾本科杂草7种,占24%,莎草2种,占4%.相对多度达10以上的杂草依次为牛筋草、马齿苋、石胡荽、粟米草、碎米莎草、马唐、鳢肠、饭包草、通泉草等9种,其中前6种相对多度在20以上,可视为当地苗圃的优势种杂草.     

湖南省棉田杂草调查

对湖南省棉花主产区棉田杂草的种类、发生规律及化学除草情况进行了调查。结果发现, 湖南省棉田常见杂草包括12科, 28种, 其中禾本科杂草占25.00%, 阔叶杂草占67.86%, 莎草科占7.14%; 一年生杂草占78.57%, 多年生杂草占21.43%。相对多度10%以上的杂草有7种, 其中马唐、牛筋草、千金子、铁苋菜、小飞蓬5种杂草为湖南省棉田杂草的优势种, 相对多度分别为37.79%、33.64%、29.15%、26.23%、23.83%。杂草发生呈现3个高峰期, 分别为5月下旬, 6月中下旬, 7月下旬至8月初, 杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法。     

清水县麦田杂草发生情况调查初报

清水县麦田杂草有12科26种,其中双子叶杂草占61.5%,禾本科杂草占19.2%,蕨类杂草占19.3%。相对多度达10以上的麦田杂草依次为离蕊芥、麦瓶草、芥菜、雀麦、离子草、蚤缀、王不留行、播娘蒿、苦苣菜、狗尾草、夏至草等11种。其中离蕊芥、麦瓶草、芥菜的相对多度分别为55.3、36.89、和25.01,为麦田的优势种群。针对发生种类,应采取优化作物布局,提高栽培管理水平,合理使用除草剂,以达到综合除草效果。     

秀山县稻田杂草发生危害及防除对策初探

运用倒置"W"9点取样法对秀山县稻田杂草进行了调查。结果表明,秀山县稻田杂草共有20科32种,相对多度在10以上的稻田杂草依次为牛毛毡、节节菜、草茨藻、鸭舌草、矮慈姑、稗、野荸荠、陌上草、水蓼等9种,其中,禾本科杂草占1%、莎草科杂草占3.3%,阔叶杂草占66%。牛毛毡、节节菜、草茨藻、鸭舌草相对多度达30以上,为当地优势杂草。根据田间草害发生状况,提出了"前除、中控、后补"的综合治理对策。     

新疆棉田杂草调查

采用倒置“W”九点取样法调查新疆棉田杂草结果明确,新疆棉田杂草有19科50种,其中禾本科杂草占18％,阔叶杂草占82％。相对多度达10以上的棉田杂草依次有马唐、田旋花、稗草、灰绿黎、画眉草、狗尾草、芦苇、反枝苋8种,其中双子叶杂草田旋花和灰绿黎,禾本科杂草马唐和稗草的相对多度在30以上,为新疆棉田杂草优势种群。     

江汉平原麦田杂草调查

运用倒置“Ｗ”９点取样法对江汉平原麦棉套作农田杂草调查,结果表明该地区麦田杂草有１４科２３种,其中禾本科杂草占２７％,阔叶杂草占６９％,莎草科占４％。相对多度达１０以上的麦田杂草依次有猪殃殃、婆婆纳、野燕麦、半夏、通泉草、狗牙根、卷耳等７种,其中猪殃殃、婆婆纳两种双子叶杂草的相对多度达５０和４０,为当地麦田优势种群。     

贵州省烤烟田杂草发生情况调查

采用倒置"W"9点取样法调查了贵州省烟地杂草发生危害情况。贵州省烟地杂草有30科74种,其中禾本科杂草12种,占16.22%;阔叶杂草60种,占81.08%;其他杂草2种,占2.70%。相对多度在10%以上的杂草分别是马唐、辣子草、狗尾草、尼泊尔蓼、旱稗、腺梗豨莶,为贵州省烟地杂草的优势种群。随着地区、海拔、土壤类型的不同,其杂草优势种群结构也不相同。     

浙沪小麦田杂草调查及优势杂草化学防除技术研究

为了明确浙沪小麦田杂草发生情况及优势杂草控制技术,采用唐氏五级目测法和随机取样计数法相结合的方法,对上海和浙江的116块冬小麦田杂草进行了抽样调查,同时采用盆栽试验和田间小区试验测定了7种除草剂对主要危害杂草的防效。结果表明,浙沪冬小麦田共调查到杂草43种,隶属于14科,其中菊科杂草种类最多,有10种,其次是禾本科杂草9种,再次是石竹科杂草5种。杂草群落组成以禾本科杂草为主,优势杂草为日本看麦娘Alopecurus japonicus Steud.、菵草Beckmannia syzigachne(Steud.) Fern.、棒头草Polypogon fugax Nees ex Steud.、硬草Sclerochloa dura(L.) Beauv.、早熟禾Poa annua L.、鹅肠菜Myosoton aquaticum(L.) Moench、救荒野豌豆Vicia sativa L.、猪殃殃Galium spurium L.和小藜Chenopodium ficifolium Smith。室内除草活性及田间药效试验结果表明,日本看麦娘可用15%炔草酯WP、5%唑啉草酯EC、30 g/L...     

Mechanical damage to annual weeds and carrots by in-row brush weeding

Field experiments were carried out in order to assess the selectivity of in-row brush weeding in carrots with a natural flora of annual weeds, represented by Urtica urens L., Stellaria media (L.) Vill., Chenopodium album L., Senecio vulgaris L., Capsella bursa-pastoris (L.) Med., Chamomilla suaveolens (L.) Pursh Buch. and Matricaria inodora L. The mechanisms by which the weeds and carrots were controlled (uprooting vs. soil covering) were studied using a portable vacuum-cleaner. Weeds at the two- to four-true-leaf stage proved to be more sensitive to brushing than carrots with two to four true leaves but, for later development stages of the weeds, there were no differences. Weeds at the six- to eight-leaf stage were only killed to an extent of 20–50%. Uprooting generally accounted for 45–90% of the weed mortality at the two- to four-leaf stage, whereas most of the mortality in carrots was the result of soil covering. The vacuum-cleaning method proved to be a simple and rapid way of determining whether plants had been killed by uprooting or soil covering. It was concluded that the major mechanism of weed control obtained by brush weeding is uprooting.     

南繁区转基因水稻田杂草种类调查

为了弄清南繁区转基因水稻田、非转基因水稻田和空白对照田杂草种类及发生情况,采取5点取样法,对3种田的田间杂草种类及危害情况进行了调查。结果表明：转基因水稻田有杂草19种,隶属11科,优势杂草为空心菜、牛毛毡、水莎草、莲子草、水苋菜、千金子,相对多度分别为37．58％、28．51％、26．24％、21．70％、21.62％、20．84％;非转基因水稻田主要杂草包括17种,隶属10科,优势杂草为空心菜、水莎草、牛毛毡、莲子草、水苋菜,相对多度分别为40．14％、29．83％、29．83％、24．11％、21．70％;空白对照田主要杂草包括12种,隶属8科,优势杂草为空心菜、水莎草、水苋菜、碎米莎草、莲子草、鳢肠,相对多度分别为60．28％、36．76％、34．98％、33.80％、29．11％、23．25％;水稻田（转基因水稻和非转基因水稻）中各优势杂草的危害程度明显低于空白对照;除了千金子,转基因水稻田中的优势杂草（空心菜、牛毛毡、水莎草、莲子草、水苋菜、碎米莎草、鳢肠）的危害程度均略低于对应的非转基因水稻。     

东北地区芝麻田杂草调查结果与分析

针对东北地区不同地区芝麻田间杂草的发生情况,采用五点取样法调查芝麻田间杂草。结果显示,东北地区芝麻田杂草约有16种,分属12科。其中,禾本科4种,占杂草种类的25％;菊科2种,占12．5％;苋科、鸭跖草科、莎草科等10科各1种,分别占6．25％。一年生杂草13种,占81．25％;多年生杂草3种,占18．75％。     

An agro-economic survey of the weeds and weeding practices in cassava (Manihot esculenta Crantz) in Colombia

A survey of weeds and weeding practices was carried out by a team of agricultural economists and agronomists on 283 farms in five Cassava growing regions of Colombia at three times during a cropping season. Seventy-one to 78% of all weed species present were broadleaved species. As cassava grew older, grass species were present to a greater and sedge species to a lesser relative frequency. Surprisingly Pteridiumaquilinum (L.) Kuhn was the most frequently listed species and Bidens pilosa L. and Cyperus rotundus L. were other frequent problems. Regional variations in the most frequently encountered species were found but several of the weeds were common to many zones. The most frequently encountered species did not usually have the highest plant populations. Most of the annual grasses, sedges and broadleaf weeds found can be controlled by currently recommended herbicides for cassava but further research is needed on Imperata cylindrica (L) Beauv., Melinis minutlftora Beauv., P. aquilinum and Sida spp. The average number of manual weedings was 3.3 per crop, occupying 48 man-days/ha which is 50% of the total labor requirements for cassava production, and more than one-third of the total costs. Reasons for not using herbicides were (1) relative costs of herbicides and labor. (2) lack of information, (3) lack of capital, (4) right herbicides were not available, and (5) herbicides were not available in small packages. This survey has usefully identified new field problems and has suggested further research programs to solve them.     

新疆核桃-小麦间作麦田杂草组成及群落特征

为明确新疆核桃与小麦间作对麦田杂草种类及群落结构的影响,于2012—2017年对新疆南疆核桃-小麦间作、单作麦田杂草发生情况进行了调查。结果表明,南疆麦区杂草有39种,隶属14科33属,其中以菊科、禾本科、藜科为主;优势杂草有9种,分别是灰绿藜Chenopodium glaucum L.、稗草Echinochloa crusgalli(L.)Beauv.、播娘蒿Descurainia sophia(L.)Schur.、扁蓄Polygonum aviculare L.、硬草Sclerochloa kengiana L.、田旋花Convolvulus arvensis L.、离蕊芥Malcolmia africana(L.)R. Br.、小蓟Cephalanoplos segetum(Bunge.)Kitam.、苣荬菜Sonchus brachyotus DC.;与小麦单作田相比,核桃-小麦间作麦田杂草物种丰富度及Shannon-Wiener指数较高,2017年物种丰富度最高达27种,代表杂草优势集中性的Simpson指数则是小麦单作田高于核桃-小麦间作麦田,2013年高达0.32;核桃-小麦间作有利于麦田播娘蒿、苣荬菜和离蕊芥发生,但不利于萹蓄发生,其它5种优势杂草在间作和单作麦田的发生密度无显著差异。     

江苏省镇江市麦田杂草发生情况调查

为了摸清江苏省镇江市麦田杂草种类、分布状况、出草规律、草相变化、防除情况等,通过倒"W"形九点取样法对镇江市麦田杂草进行了调查。调查结果显示镇江市麦田杂草有29科99种,日本看麦娘、菵草、猪殃殃、看麦娘、稻槎菜、硬草、繁缕、大巢菜、荠菜、涩荠、野老鹳草、牛繁缕、早熟禾为该地区主要危害性杂草,其中菵草、日本看麦娘、猪殃殃为麦田杂草群落优势种。不同地形区域杂草种类和优势种不同。镇江市麦田杂草由20世纪90年代初以看麦娘、日本看麦娘和猪殃殃等为主演变为以菵草、日本看麦娘、猪殃殃为主,稻槎菜、硬草、繁缕等发生较重。出草高峰集中在小麦播后15 d左右,具体到镇江来说11月底至12月上旬为杂草发生高峰期。针对镇江本地杂草发生情况,制定了以土壤封闭和茎叶处理相结合的防控技术方案。     

出芽短梗霉菌菌株PA-2的除草活性及对作物的安全性

从青海省平安县发病杨树叶片上分离得到菌株 PA-2,其发酵滤液对多种阔叶杂草表现出较好的除草活性。对该菌株的培养特征和16S rDNA基因序列分析后,确定其为短梗霉属出芽短梗霉菌Aureobasidium pullulans。盆栽试验表明,其发酵滤液对供试阔叶杂草猪殃殃、藜、冬葵、酸模叶蓼及禾本科野燕麦的鲜重防效分别达到87.25%、78.46%、82.25%、62.11%、80.27%。作物安全性试验结果表明,其发酵滤液对小麦、蚕豆、青稞很安全,对油菜、豌豆有轻微影响。综上所述,菌株 PA-2具有作为微生物除草剂的开发潜力。     

Efficacy of chemical weed control in spring cereals in Finland

A national survey was conducted in Finland from 1982 to 1984 to determine the main weed species in spring cereals and the efficacy of herbicides on Finnish farms. The most common dicotyledonous weeds producing the highest biomass in spring cereals were Chenopodium album L., Galeopsis spp. L., Stellaria media (L.) Vill. and Lapsana communis L. The main grass weed was Elymus repens (L.) Gould. The average reduction of weed biomass by herbicide treatment was 75%. More reliable efficacy was obtained with herbicide mixtures than with MCPA alone.