菏泽地区棉田杂草调查初报

运用倒置“W”9点取样法,对菏泽地区棉田杂草调查结果表明,该地区棉田杂草有12科26种,其中禾本科杂草占30．8％,阔叶杂草占61.5％,莎草科占7．7％。相对多度10以上的杂草依次有马齿苋、牛筋草、马唐、铁苋菜、碎米莎草、反枝苋、香附子等7种,其中,马齿苋、牛筋草、马唐、铁苋菜4种杂草的相对多度分别为55．12、51．84、45．7、35．37,是当地棉田杂草的优势种。     

湖北省冬小麦田杂草种类与群落特征

为明确湖北省冬小麦田杂草的发生危害现状和群落组成特征,运用倒置"W"9点取样法对该省冬小麦主产区麦田杂草群落进行了调查。结果表明,湖北省冬麦田杂草有16科39种,其中禾本科杂草占18%,阔叶杂草占82%。相对多度达15以上的杂草依次为猪殃殃、牛繁缕、日本看麦娘、野老鹳草、野燕麦和大巢菜等6种,其中猪殃殃、牛繁缕和日本看麦娘的相对多度分别为74.19、51.66和30.36,为优势种类。     

大豆化学除草技术

大豆化学除草技术王险峰，关成宏，刘恩旭黑龙江省农场总局植保站黑龙江垦区的大豆化学除草从７０年代初起步，随着除草剂的引进。大豆化除迅速发展，８０年代初中期大豆化除面积已达大豆种植面积的７５％，近几年达９ｏ％以上。垦区大豆田杂草基数大、种类多、持续时间长...     

新疆伊犁地区亚麻田杂草调查

采用倒置" W"9点取样法对新疆亚麻主栽区--伊犁地区亚麻田进行了杂草调查.结果表明伊犁地区亚麻田的杂草有15科26种,单子叶杂草狗尾草、稗草、野燕麦,双子叶杂草灰绿藜、卷茎蓼的相对多度在20以上,是亚麻田杂草的优势种群.     

新疆伊犁地区亚麻田杂草调查

采用倒置“W”9点取样法对新疆亚麻主栽区——伊犁地区亚麻田进行了杂草调查。结果表明伊犁地区亚麻田的杂草有15科26种，单子叶杂草狗尾草、稗草、野燕麦，双子叶杂草灰绿藜、卷茎蓼的相对多度在20以上，是亚麻田杂草的优势种群。     

阔草清防除大豆杂草鸭跖草效果试验

通过2001年至2002年两年应用研究表明，阔草清水分散粒剂可有效防除大豆田难治杂草鸭跖草，防除效果迭90％。还可兼治蓼、苋、苍耳等杂草，对大豆没有药害，并有明显增产效果，增产达19．4％；应用的配方为：乙草胺(或禾耐斯) 阔草清 赛克或乙草胺(或禾耐斯) 阔草清。     

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。     

冬季亚麻杂草种类危害及防除研究

本文调查研究了州内亚麻种植地区的田块杂草种类、分布和发生规律。查清杂草共有101种，隶属25科，发生危害重的有7科26种，占25．74％；双子叶杂草77种，占76．23％，单子叶杂草22种，占21．78％，蕨类杂草2种，占1．98％。一年生杂草42种，占42．58％，越年或一年生杂草29种，占28．7l％，多年生杂草30种，占29．7l％。杂草随亚麻的播种而生长，至枞形期达最高峰，88—1231株／m^2。防治上在亚麻枞形期（株高5—10cm）、杂草2—3叶期选择50％敌草隆＋5％精喹禾灵或50％敌草隆＋56％二甲四氯钠盐，兑水喷雾，防除效果达90％以上。     

夏大豆田间杂草发生情况及防除措施

由于夏大豆生长期气温高．雨水充足．有利于杂草的发生和生长．近几年．鲁南及鲁西南地区大豆田杂草发生逐年加重,杂草种类多、危害重,一般减产20％～50％,成为制约当地夏大豆产量的主要因素之一。针对这种情况．通过对夏大豆田杂草发生情况、发生特点以及发生原因进行调查分析．并与生产实践相结合,多次进行药剂试验．总结出一套夏大豆田间杂草综合防除技术。     

10%氯嘧磺隆混配剂防除大豆田杂草示范总结

近几年,大豆田杂草对大豆的生长造成极大威胁,在大豆生长期间,杂草与大豆争水、争肥,严重影响大豆产量,江苏克胜集团克山天华化工有限公司生产的10%氯嘧磺隆混配剂是防除大豆田杂草的良好药剂,经试验证明对大豆田各种杂草的防效达90%以上。     

龙门县农田草害种群组成危害程度及防除策略

通过调查发现，龙门县水稻杂草有15科40种，柑桔杂草有16科53种，花生杂草有8科30种，蔬菜杂草有12科35种。危害水稻的优势种是四叶萍，亚优势种是鸭舌草和黑藻；危害柑桔的优势种是马兰和马唐，亚优势种是狗尾草和狗牙根；危害蔬菜、花生的优势种因海拔、生态环境不同差异较大。根据调查结果，对农田草害造成的粮油损失进行估算，并提出了针对性的防除策略。     

Efficacy of four post-emergence herbicides applied at reduced doses on weeds in summer maize (Zea mays L.) fields in North China Plain

Field experiments were conducted in 2010 and 2011 in a typical location of North China Plain to evaluate weed control efficacy of four post-emergence herbicides nicosulfuron, mesotrione, topramezone and the combination of mesotrione/nicosulfuron when they were applied at reduced doses at different weed growth stages. Experimental results showed that nicosulfuron, topramezone and the combination of mesotrione/nicosulfuron provided better weed control efficacy than mesotrione when they were applied at their label recommended doses at the 2- to 3-leaf and 4- to 5-leaf stages of weeds; nicosulfuron and mesotrione/nicosulfuron could at least be reduced by 33% and topramezone reduced by 67% without sacrificing total weed control efficacy and maize grain yield. Nicosulfuron and its combination with mesotrione could effectively control broadleaved and grass weeds when their doses were reduced by 67% and by 33%, respectively. Topramezone could effectively control broadleaved and grass weeds when its dose was reduced by 67%. The efficacy of mesotrione in controlling grass weeds was bad even at the label recommended dose. All four herbicides tested did not affect the maize grain yield.     

Chemical control of weeds in transplanted tomatoes in Saudi Arabia

The herbicides metobromuron, diphenamid and dinitramine were tested either singly or in combination with dalapon for the control of weed species in transplanted tomato crops in Saudi Arabia, during 1979 and 1980. All herbicides were effective in controlling Chenopodium murale L., the primary broad-leaved weed in the area. However, they were less effective against other broad-leaved weed species and, even in combination with dalapon, failed to reduce populations of grass weeds. Tomato seedlings showed various degrees of injury: dinitramine was the most phytotoxic herbicide, followed by metobromuron and diphenamid. No toxicity was observed for dalapon. Diphenamid was the most promising herbicide for controlling weeds and producing significantly higher yields of tomatoes.     

苏北垦区豆田杂草生长为害习性

苏北垦区豆田杂草分属15科,36属,41种,恶性杂草有稗,苍耳等9种。在大豆整个生育期间通常出现1～2个萌发高峰,主要集中在6月中旬～7月下旬。杂草种子于8～10月成熟。种子在土壤中的埋深及出苗期,直接影响杂草的出苗和繁殖。杂草与大豆的相互竞争,以在大豆播种一个月后最为剧烈。0～2cm和6～25cm耕层中贮葳的杂草种子最多。     

不同耕作模式对玉米田杂草发生规律的影响

在免耕、旋耕和翻耕玉米田试验区调查杂草种类和出苗数量,并在玉米生长中后期调查杂草种类、株数和鲜重。结果表明,不同耕作模式玉米田杂草发生规律有明显差异。免耕、旋耕和翻耕玉米田禾本科杂草高峰期都在播种后5周发生;阔叶杂草发生高峰期不同,免耕田为播种后1周,旋耕和翻耕田均在播种后2周。杂草种类不同,玉米生长中后期,免耕田有8种杂草,旋耕田有10种,翻耕田有12种;杂草发生总量不同,免耕田杂草总量最多,旋耕田居中,翻耕田最少;杂草单株鲜重不同,免耕田杂草单株鲜重最低,旋耕田居中,翻耕田最高。     

Effect of herbicides on weed management in dry-seeded rice sown under different tillage systems

In India, dry-seeded rice (DSR) production systems are rapidly replacing conventional rice production systems due to various advantages. DSR systems can be managed under zero-till (ZT) conditions or after a preparatory tillage, often referred to as conventional tillage systems (CONT). Although previous reports indicate the contribution of tillage to weed suppression, the effect of one-time preparatory tillage in a DSR system could vary depending on the dominant weeds in the system, vertical seed distribution and the weed seed dynamics. A study was conducted to test the efficacy of ZT and CONT and their interaction with herbicide treatments on the weed population dynamics and rice grain yield in 2010 and 2011. Tillage systems did not affect weed emergence, weed biomass, tiller production and crop yield. However, herbicide treatments varied in their efficacy on individual weeds. Hand-weeding treatments and pendimethalin combined with hand weeding did not effectively control Cyperus rotundus L. and Panicum maximum Jacq. (a perennial grass weed with underground parts). The herbicide combination of metsulfuron and chlorimuron was effective in controlling C. rotundus but not grass weeds. This indicates the need for sequential applications of herbicides for grass weed control or integration of hand weeding to achieve broad-spectrum weed control. Apart from hand weeding (three times), treatment with penoxsulam–cyhalofop and pendimethalin followed by (fb) hand weeding resulted in low weed density, high tiller production and grain yield. The study clearly indicates that tillage does not always lead to weed suppression compared with ZT, and herbicides must be chosen based on the dominant weeds in a system. The results of this study are pertinent as herbicide-resistant weeds are rapidly evolving under continuous herbicide selection pressure, which warrants studies on enhancing productivity through low-input, environmentally friendly and sustainable production technology.     

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/hm2),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 k...     

海南不同市县旱田代表性杂草发生规律研究

为全面了解海南不同市县旱田代表性杂草全年的发生规律,从2008年至2009年,采用全年定点、定时观测的方法对海南7个市县杂草自然萌发情况进行调查。结果表明:海南不同市县定点观测样方里共有代表性杂草20科60种,其中菊科、禾本科、苋科、豆科和茜草科较多,占杂草总数的63%;外来入侵杂草有29种,占总数的48%;重要值大于5的优势种杂草有12种,占所有杂草的20%。6月是杂草种类萌发高峰,达15种。海南杂草年平均萌发量达1 060株/0.25 m2,其中万宁最高,年平均萌发量达1 559株/0.25 m2;定安最低,年平均萌发量达519株/0.25 m2。海南杂草全年发生数量有两个高峰期:一个在4月,萌发率为16%;一个在9月,萌发率为10%。全年大部分杂草在3~7月和9月萌发,萌发率为全年的70%。在海南,温度均能满足杂草萌发需要,降雨量是杂草发生的主要限制因子。     

Tolerance of selected weed species to broadcast flaming at different growth stages

Organic producers rank weeds as the most important pests that limit their crop production. In order to optimize the use of propane flaming as a weed control tool, the objective of this study was to test tolerance of selected weed species to broadcast flaming performed at different growth stages. Six annual species, including one grass [barnyardgrass (Echinochloa crus-galli)] and five broadleaves [field bindweed (Convolvulus arvensis), kochia (Kochia scoparia), ivyleaf morning glory (Ipomoea hederacea), velvetleaf (Abutilon theophrasti) and Venice mallow (Hibiscus trionum)] were flamed at three growth stages with six doses of propane. The propane doses applied were 0, 12, 31, 50, 68 and 87 kg/ha. Flaming treatments were applied utilizing a custom built flamer mounted on a four-wheeler moving at a constant speed of 6.4 km/h. Species response to propane were described by log-logistic models based on visual injury ratings and dry matter (DM) for each weed species. Overall response to flaming varied among species, growth stage and propane dose. Broadleaf weeds were more susceptible to flaming than the grass regardless of the growth stage. A dose of 76 kg/ha of propane was needed to obtain 90% DM reduction for 7-leaf (L) barnyardgrass compared to much lower doses of 40, 49, 55, 56 and 51 kg/ha propane for 8-L bindweed, 6-L kochia, 10-L morning glory, 7-L velvetleaf and 5-L Venice mallow, respectively. Moreover, the tolerance of both grassy and broadleaf weed species to broadcast flaming increased with increase in plant size. A 90% DM reduction in velvetleaf was obtained with 42, 56 and 102 kg/ha of propane for 5-L, 7-L and 16-L stages, respectively. The tested broadleaf weed species were effectively controlled (90% DM reduction) with propane dose of 30–60 kg/ha when flamed at early growth stages (3-L to 14-L), while the same dose of propane provided only 80% DM reduction in barnyardgrass when flamed at vegetative stages (4-L to 7-L). It was not possible to obtain 90% DM reduction in barnyardgrass when flamed at flowering stage with the propane doses tested in this experiment.