陕西省麦田杂草种类分布及防除技术

随着小麦栽培水平的不断提高,陕西麦田杂草的种群数量逐年上升,一般麦田有杂草8万~10万株/667m2,与小麦争水、争肥、争光,严重影响小麦的产量和品质。通过几年来对陕西麦田杂草的调查、药剂试验示范和推广应用,现就陕西麦田杂草的种类、分布、除草剂的发展变化及麦田杂草防除技术简述如下。1陕西省麦田杂草的种类与分布1.1杂草的种群变化及化除情况陕西省从20世纪60年代中期开始进行化学药剂除草试验示范,最早引进五氯酚钠、敌稗等,进行水稻田杂草防除试验。20世纪70年代引进燕麦灵、燕麦敌2号、敌草隆、灭草隆、棉草隆、除草醚防除麦田、棉…     

闽中山区垅田杂草的治理

我县地处闽中山区，戴云山脉西侧，有三分之一以上的水田在山找、半山城。由于杂草的危害，影响了水稻的高产稳产。为消除草患，每年都要花费大量的人力、物力进行人工防除。人工防除劳动强度大。花工多、除草不及时、不彻底，且持效期短。近年来，我们采取人工防除与药剂防除相结合的综合治理技术，有效地控制了坑田杂草的发生危害。每亩优田节省工时2～3天，减少工本投入30～40元，取得了显著的经济效益和社会效益。同时，减轻劳动强度，提高了工效。（一）优田杂草的危害拢田杂草与水稻争水、争肥。争光、争空间，影响了挑田水稻的生长。…     

野燕麦的发生现状与燕麦畏的应用

一、野燕麦的发生与危害野燕麦是麦田恶性杂草,发生普遍,危害严重;争肥、争水、争阳光,导致小麦减产。在世界上,欧洲和北美发生严重,英国、加拿大等国家在60至70年代曾设立野燕麦防除委员会,专门进行研究和指导农田野燕麦的防除工作,取得了显著成绩。我国60年代初期开始,     

烟田杂草防除研究进展

烟草在我国已有超过400年的种植历史,是我国重要的经济作物.烟田杂草与烟草争光、争水、争肥,阻碍作物的生长,给烟草生产带来巨大的损失.本文对烟田杂草的种类、分布以及防除研究的现状进行了综述,并讨论了烟田杂草综合防治中存在的问题以及今后的发展方向.     

几种除草剂防除蔗田杂草效果试验

几种除草剂防除蔗田杂草效果试验罗桂合覃庆荣（象州县糖办５４５８００）（广西博华食品有限公司）１９９８－０４－１３收稿在甘蔗生产中,杂草与其争光争肥争水分,是影响甘蔗产量的重要因素之一。据调查,本地蔗田杂草主要有稗草、马唐、水花生、节节菜、莎草、藜、春...     

苗圃杂草化学防除技术

苗圃杂草化学防除技术李向东，赵国晶（云南省农科院植保所，６５０２０５）草害是苗圃中育苗的一大障碍，杂草不但与苗木争水、争光、争养份，抑制苗木生长，而且还是传播病虫害的媒介。现阶段苗圃中大部分除杂草靠人工拔草，效率低，成本高，杂草易拔断并拔松苗木根部土...     

乙草胺防除花生地杂草的效果

乙草胺防除花生地杂草的效果侯茂芬，陈秉瑶（广西鹿寨县植保站）花生是广西鹿寨县的主要油料作物，常年种植面积５．５万亩。花生生长期间雨水充沛、气候温和，既适花生生长，亦宜杂草的生长。本地杂草种类多、数量大，与花生争肥、争水、争光，一般造成减产２０～３０％...     

花生田杂草化学防除现状及趋势

花生田杂草种类繁多,数量巨大,发生普遍,与花生争光、争肥、争水,直接影响到花生的产量和质量。杂草还是病虫害的寄主,可以助长病虫害的发生蔓延。人工锄草虽然可以除去杂草,但耗工耗时,且容易伤害花生幼苗。花生田化学除草具有不伤花生植株根系和茎叶,因而避免植株感染病害,且有省工、省时等作用。本文将花生田杂草化学防除现状及趋势综述如下。     

稗草生物学特性的調查研究初报

稗草是稻田中的主要杂草,它与水稻争肥料、争阳光、争水分,严重危害水稻生产。为防除稻田稗草,近年来,我对稗草的种类、形态、生理特性等进行了如下的初步调杳研究。     

烟田杂草的综合防除

烟田杂草与烟草争光、争水、争肥，阻碍作物的生长；降低烟叶的产量、影响烟叶的品质；妨碍烟叶采收、中耕施肥等农事操作；增加生产费用和劳动力；同时还是许多病虫害的中间媒介和寄主，诱发病虫害的发生和蔓延。因此，烟田草害是烟叶生产中一个突出的亟待解决的问题。为了解决生产实际问题，坚持农业的可持续发展，烟田杂草的防除应坚持贯彻综合防除的策略。现介绍如下。     

A call for weed research in industrial hemp (Cannabis sativa L)

Industrial hemp (Cannabis sativa L.) is grown in more than 30 countries for fibre, seed and flowers, and acreage of cultivation is increasing globally. Hemp has long been promoted as a crop that competes well with weeds and requires little intervention to prevent yield losses. We conducted a literature review and found little peer‐reviewed research to support this claim. We identified only three articles that specifically addressed weed management under field conditions and none provided information on hemp yield losses from weeds. These findings highlight a clear need for research‐based information on interactions between weeds and hemp to address potential yield losses under various production conditions and provide a research‐based framework for weed management in industrial hemp.     

Precision farming for weed management: techniques

Site-specific weed control techniques have gained interest in the precision farming community over the last years. Managing weeds on a subfield level requires measuring the varying density of weeds within a field. Decision models aid in the selection and adjustment of the treatments, depending on the weed infestation. The weed control can be done either with herbicides or mechanically. A site-specific herbicide application technology can save large amounts of herbicides. Mechanical weed control techniques adapting to the weed situation in the field are applicable to a wide spectrum of crops. Site-specific techniques for the detection and management of weeds are presented. A system for the discrimination of different weed species and crops from images is described, which generates weed maps automatically. Models for the yield effect of weeds are developed and applied in on-farm-research experimental setups. Economic weed thresholds are derived and used for a herbicide application with a patch sprayer.     

发展化学除草重视综合治理

我国农田杂草有２５０多种，全国农田受草害面积４３００多万ｈｍ２，平均受草害减产１３．４％，每年减产粮食１７５０万ｔ，皮棉２５．５万ｔ和大豆５０万ｔ。传统农业生产采用机械作业及人力等除草。随着农村经济的发展，化学除草面积迅速扩大，全国农田化学除草面积从１９７５年的１７０万ｈｍ２增加到１９９５年的４１３３万ｈｍ２。但是，长期化学除草也带来了除草剂土壤残留对后茬作物药害、农田杂草种群更替和产生抗药性等新问题。必须重视农田杂草综合治理，通过采用各种有效的农业技术措施，为农作物保持良好的生态条件，结合化学除草才是最有效的防除杂草方法     

Interannual variation in weed biomass on arable land in Sweden

Data were analysed on weed biomass from untreated plots in 2672 field experiments conducted in spring- and autumn-sown cereal and oilseed crops in Sweden 1972–1992. The coefficient of variation (CV) among years in the biomass of annual weeds per square metre was 29% in autumn-sown crops. In spring-sown crops, which had less weed biomass, the corresponding value was 49%. The biomass of summer annuals varied most (105%). Low winter temperatures seemed to increase the biomass of weeds in autumn-sown crops. In spring-sown crops, weed biomass production was higher in years with high rainfall during late spring. Partial ordination (pCCA) of weed data indicated that the interannual variations in autumn-sown crops were mainly manifested by the occurrence of summer annuals. Results from similar ordination of data from spring-sown crops were partly explained by the occurrence of winter annuals.     

Reduction of growth and reproduction of Cyperus esculentus by specific crops

To assess the potential contribution of growing highly competitive crops to control Cyperus esculentus in the Netherlands, the influence of silage maize, hemp, winter barley and silage winter rye on emergence, growth and reproduction of this weed was studied in two field experiments. Growth and reproduction of C. esculentus (determined both as tuber production per plant and density of the weed in the subseuent crop maize) was reduced by each crop, compared to plots in which no crop was grown. In hemp, hardly any tuber production was observed. By growing a green manure crop after harvest of the winter barley the tuber production of the weed was reduced to about 40% of that in winter barley followed by fallow. Decreasing the light regime in a greenhouse experiment in the same order as was observed in the crops winter barley, maize and hemp, caused a similar reduction of tuber production to that found in the field. Therefore, it is suggested that competition for light is the main factor explaining the observed crop effects on the population dynamics of the weed. It is concluded that growing competitive crops as hemp in rotation may effectively complement chemical control of C. esculentus.     

8%精噁唑甘草胺可分散油悬浮剂对直播水稻田禾本科杂草的防效及后茬作物的影响

为明确新型水直播稻田除草剂精噁唑甘草胺以及对照药剂对于直播稻田禾本科杂草的防除效果以及对于水稻及后茬作物的安全性, 于2019年在江西宜春市上高县水稻田进行了大田杂草防效试验以及后茬作物安全性研究。结果表明:8%精噁唑甘草胺OD对于直播水稻田的禾本科杂草具有良好的防除效果, 120 g/hm2 以及200 g/hm2 剂量处理对于禾本科杂草的防效均在88%以上。而且所有处理对于水稻均无药害产生, 实现增产, 并对后茬作物生长安全。综上所述, 新型直播稻田除草剂精噁唑甘草胺对直播水稻田禾本科杂草有良好防除效果, 可以在市场上推广应用。     

WEEDS OF TOMATO AND CORN FIELDS IN TWO REGIONS OF ONTARIO

Summary. Amaranthus retroflexus, Chenopodium album, Ambrosia artemisiifolia, Setaria glauca, S. viridis and Echinochloa crusgalli were the most widespread and abundant of the 103 weed species found in eighty-eight fields of tomatoes ( Lycopersicon esculentum ) and sweet corn ( Zea mays ) surveyed in Prince Edward County and in Essex and Kent Counties during 1960 and 1961. None of the important weeds in either crop occurred exclusively in that crop. Differences in weed floras were greater between regions than between crops. Abutilon theophrasti, Euphorbia maculata, Apocynum cannabinum var. suksdorfii and Physalis virginiana var. subglabrata , important weeds in both crops in Essex and Kent, were not found in any surveyed field in Prince Edward County. Average numbers of weed species per field were 15.7 in Prince Edward County and 12.9 in Essex and Kent. Small dense infestations of Fumaria officinalis and Salvia reflexa , rare weeds in Canada, were discovered in Prince Edward County.
Mauvaises herbes des cultures de tomates et du maïs dans deux régions de l'Ontario     

Biocontrol efficacy of Colletotrichum truncatum for hemp sesbania (Sesbania exaltata) is enhanced with unrefined corn oil and surfactant

In greenhouse and field experiments, an oil-in-water emulsion of unrefined corn oil and Silwet L-77 increased the biological weed control efficacy of Colletotrichum truncatum (Schw.) Andrus et Moore for control of the weed, hemp sesbania ( Sesbania exaltata [Raf.] Rydb. ex A.W. Hill). The surfactant – corn oil emulsion stimulated germination and appressoria formation in vivo and in vitro and delayed the need for dew. We hypothesize that the corn oil protected the conidia from desiccation during the dew-free period and the surfactant stimulated spore germination and appressoria formation. In field experiments conducted over 3 years, a single application of a 50% (v/v) unrefined corn oil tank mixture containing 0.2% (v/v) Silwet L-77 surfactant controlled hemp sesbania in soybeans an average of 95%. Aqueous fungal suspensions or adjuvants alone did not visually affect or control hemp sesbania. The soybean yields were significantly higher in the plots where weeds were effectively controlled. These results suggest that formulating C. truncatum in unrefined corn oil and surfactant greatly increases its infectivity and the biocontrol potential of this pathogen.     

What criteria are relevant for predicting the invasive capacity of a new agricultural weed? The case of invasive American species in France

In Europe, exotic species are assessed for their potential threat only after they have already become weeds. To test hypotheses underlying risk assessment procedures, 274 North and South American exotic species naturalized in France were compared to differentiate environmental from agricultural weeds and to characterize weeds of several crops. Most agricultural exotic weeds belonged to the Asteraceae and the Poaceae, but proportionally to the total number of invasive species from a family the most successful families were the Amaranthaceae, Euphorbiaceae and Poaceae. Weed status in North and South America was the best predictor of agricultural weed status in France, and a pre-1900 date of introduction was associated with a greater likelihood of having become a major weed. The characteristics of 78 species present in field crops were examined in relation to management practices. In annual crops, the life-cycle compatibility of weeds appeared to be the main factor of selection. Exotic species differed in their C4 photosynthesis pathway in maize and rice. In vineyards, many ecological strategies are possible because the habitat is heterogeneous. Intrageneric comparison of exotic and native species showed a superior relative growth rate and higher biomass production under nutrient-rich conditions for exotics. However, it is still difficult to find a predictive function that fits well with all observed cases of weed invasion.     

The role of allelopathy in agricultural pest management

Allelopathy is a naturally occurring ecological phenomenon of interference among organisms that may be employed for managing weeds, insect pests and diseases in field crops. In field crops, allelopathy can be used following rotation, using cover crops, mulching and plant extracts for natural pest management. Application of allelopathic plant extracts can effectively control weeds and insect pests. However, mixtures of allelopathic water extracts are more effective than the application of single-plant extract in this regard. Combined application of allelopathic extract and reduced herbicide dose (up to half the standard dose) give as much weed control as the standard herbicide dose in several field crops. Lower doses of herbicides may help to reduce the development of herbicide resistance in weed ecotypes. Allelopathy thus offers an attractive environmentally friendly alternative to pesticides in agricultural pest management. In this review, application of allelopathy for natural pest management, particularly in small-farm intensive agricultural systems, is discussed.