Predicting the growth and competitive effects of annual weeds in wheat

The growth and competitiveness of 12 annual weed species were studied in crops of winter wheat, in which weeds were sown to give a wide range of plant densities. Weed growth patterns were identified; early species which senesced in mid-summer were less competitive than those with a growth pattern similar to that of the crop. Most species had little effect on crop yield in 1987, and this was attributed to a high crop den sity. Crop yield-weed density relationships for all species in 1988 and for Galium aparine in 1987 were well described by a rectangular hyperbola. Species were listed in the following competitive order based on the percentage yield loss per weed m^?2: Avena fatua > Matricaria perforata > Galium aparine > Myosotis arvenis > Poa trivialis > Alopecurus myosuroides > Stellaria media > Papaver rhoeas > Lamiumpur-pureum > Veronica persica > Veronica hederi-folia > Viola arvensis. Prediction of yield loss is discussed. The assumptions inherent in using Crop Equivalents (based on relative weights of weed and crop plants), are challenged; with intense competition, weed biomass at harvest failed to replace lost crop biomass, and harvest index was reduced. It is concluded that a competi tive index, derived from yield density relation ships, and expressed as the percentage yield loss per weed m^?2, is more likely to reflect the com petitive ability of a species than an index obtained from plant weights in the growing crop.     

旱地小麦品种筛选鉴定及其形态特征探讨

通过18 a对旱地小麦品种筛选鉴定方法的研究与实践，参考国内外学者的经验，提出在区域化试验鉴定的基础上，采用田间直接鉴定与干旱棚鉴定、实验室鉴定相结合的抗旱性鉴定方法。并归纳出一套以抗旱性指数为主，结合株高、穗下节长、穗粒数、千粒重的敏感系数等形态指标及根系活力、细胞膜透性、叶片相对含水量、叶绿素含量等生理生化指标体系，对小麦品种的抗旱性进行综合评判分析。同时对旱地小麦品种的地上部和地下部形态特征也进行了探讨。     

2甲4氯钠AS对春小麦田阔叶杂草的防效

13％2甲4氯钠AS对一年生阔叶杂草密花香薷、遏兰菜、藜株防效和鲜重防效分别达75．00％～95．00％和81．68％-98．27％,对田间总草的株防效和鲜重防效分别达82．96％和95．65％。对春小麦安全,除草后春小麦明显增产。     

小麦引进品种对小麦黄花叶病的田间抗性鉴定

利用田间抗性鉴定方法对110个小麦引进品种在自然病圃区进行了对小麦黄花叶病的抗性鉴定。结果表明 ,不同小麦品种对小麦黄花叶病抗性有显著差异 ,抗性较好的品种有55个 ,其中有34个品种生育期接近于扬麦158,且田间性状较好。     

Growth parameters enhancing the competitive ability of corn (Zea mays L.) against weeds

In order to determine which plant growth parameters enhanced the competitive ability of corn ( Zea mays ) against weeds, a field study was conducted at the Agricultural Research Farm, Razi University, Kermanshah, Iran. A factorial experiment based on a randomized complete block design with four replications was used. The factors consisted of weed treatments (including weedy and weed-free during all of the growing season) and corn cultivars (including KSC 260, KSC 302, KSC 500, KSC 647, KSC 700, and KSC 704). The plant growth parameters under study consisted of height, plant dry weight, the number of tillers, leaf area index, specific leaf area, crop growth rate, relative growth rate, and net assimilation rate. The results indicated that the cultivars, KSC 700 and KSC 704, had the highest competitive ability and the cultivars, KSC 302 and KSC 260, had the lowest competitive ability. The competitive ability of the cultivars, KSC 500 and KSC 647, was intermediate. All of the growth parameters under study, except the number of tillers, indicated a positive and significant correlation with competitive ability, and the relative growth rate showed the highest correlation. Variable selection using the stepwise multiple linear regression method revealed that, among the growth parameters under study, both the relative growth rate and the specific leaf area were the best predictors of corn cultivar competitiveness.     

Early vigour and allelopathy – two useful traits for enhanced barley and wheat competitiveness against weeds

The objectives of this study were to identify traits in spring barley (Hordeum vulgare) and spring wheat (Triticum aestivum) related to the competitive ability of the crop and to determine their importance. Weed biomass 1–2 weeks prior to ear emergence was used as a measure of genotypic differences in competitiveness against weeds. Crop trait measurements comprised early crop biomass, early shoot height, straw length, heading and maturity. Early crop biomass 1–2 weeks prior to ear emergence was used as an overall trait for the various characters related to early vigour. In addition to these morphological traits, the potential allelopathic activity of the tested cultivars was determined using an agar-based bioassay with Lolium perenne (ryegrass). In both barley and wheat, multiple regression analysis revealed that early crop biomass and potential allelopathic activity were the only parameters that significantly contributed to competitiveness. In barley, early crop biomass explained 24–57% of the observed genotypic variance across 4 years, allelopathic activity explained 7–58% and combined they explained 44–69% of the observed genotypic variance. In wheat, the corresponding figures were lower: 14–21% for early biomass, 0–21% for allelopathic activity and 27–37% when combined. Model predictions suggested that new cultivars with increased early vigour and allelopathic activity offer a potential to further reduce weed interference.     

麦极等防除麦田禾本科杂草的效果

15％麦极WP是一种安全、高效的麦田除草剂,在秋季使用最适宜用量为30ml／667m^2。     

小麦不同抗性品种对6种杀菌剂防治小麦白粉病效果的影响

在河北廊坊采用田间小区试验对种植不同抗性小麦品种情况下6种杀菌剂防治白粉病的效果进行了研究。结果表明, 6种杀菌剂中18%烯肟菌酯·氟环唑SC和20%烯肟菌酯·戊唑醇SC在抗病品种和感病品种上的田间小麦白粉病防效均显著优于20%三唑酮EC, 所有供试杀菌剂同一使用剂量下在高抗品种‘保丰104’上的防效要显著高于感病品种‘京双16’上的防效, 甚至较低剂量施药水平下(105 g/hm2)在‘保丰104’上对白粉病的防效要高于或显著高于高剂量施药水平下(150 g/hm2)在‘京双16’上的防效, 但参试的多数杀菌剂同一施药量情况下在中感品种‘众麦2号’和高感品种‘京双16’上的防效无显著差异。该研究说明以抗性品种为基础, 结合使用合适的杀菌剂, 可有效减少杀菌剂施用量, 此研究结果可为杀菌剂的减量施用提供依据。     

我国小麦田禾本科杂草对精噁唑禾草灵的抗药性研究进展

小麦是我国主要的粮食作物, 麦田草害的发生与危害严重影响小麦的产量与品质。我国小麦田的禾本科杂草主要包括日本看麦娘、看麦娘、菵草和多花黑麦草等, 田间杂草防除主要依靠化学除草剂。精噁唑禾草灵自20世纪80年代进入我国市场以来, 长期用于小麦田禾本科杂草防除, 已经报道麦田多种禾本科杂草对精噁唑禾草灵产生了高水平抗药性。为更加科学合理地控制小麦田杂草的发生与危害, 一些学者就麦田禾本科杂草对精噁唑禾草灵的抗药性水平监测和抗性机理进行了系统研究。本文系统总结了我国小麦田抗精噁唑禾草灵杂草的发生种群、抗性水平、靶标酶抗性机理与非靶标抗性机理, 还梳理了抗性杂草的交互抗性与多抗性发生情况, 分析了我国在抗性杂草治理方面的经验以及面临的问题, 为农田杂草防除提供指导。     

河北省小麦田杂草防治技术进展

小麦是河北省第一大种植作物 ,常年种植面积2 4 6 .7万hm2 左右。随着农民种植水平、农业机械化程度的不断提高 ,麦田杂草成为制约小麦高产的主要障碍之一。全省小麦田杂草的发生面积超过2 13 3万hm2 ,每年因草害造成小麦产量损失 10 %～15 % ,重发田块高达 30 %～ 5 0 %。为了提高杂草的防除水平 ,河北省植物保护总站从 1998年在农业厅立项实施了小麦田杂草无害化治理技术与推广 ,几年来在广大植保技术人员的共同努力下 ,经过大量试验、示范以及组织推广 ,使麦田杂草的除治工作有了较大进步。1　基本摸清了麦田常见杂草种类和群落分布1.1　…     

特丁净防除小麦田杂草田间药效试验报告

50％特丁净SC通用名为Terbutryn，化学名为N2-特丁基-N4-乙基-6-甲硫基-1，3，5-三嗪-2，4-二胺，是近年来开发的内吸传导型除草剂，可用于芽前、芽后除草，土壤中持效期3～10周。主要用于冬小麦、大麦、高梁、向日葵等作物田，防除一年生及多年生禾本科杂草、双子叶杂草。     

The potential of mini-ridging for controlling intrarow weeds: estimating minimum lethal burial depth

Weed management using synthetic herbicides is undergoing a global decline, necessitating a re-evaluation of existing control measures and the development of novel weed management tools. ‘Mini-ridging’ is a non-discriminatory, physical weeding method that functions by burying weeds in the intrarow with a laterally shifted ridge of soil. In glasshouse trials using potted plants, we found that plant recovery after soil application was influenced by plant size, which in turn was influenced by plant species, developmental stage and/or age. The likelihood of plant recovery after soil application was negatively related to the depth of soil applied: very few plants survived total coverage by soil but, conversely, survival could be substantial if some parts of the plants were not covered. The results suggest that burial under a depth of 6 cm of soil would eliminate most plants regardless of species or growth stage. Larger plants would require the application of a greater total depth of soil to achieve this 6 cm of soil cover, and weed management would, therefore, tend to be more successful and more practical if weeds were targeted when still small. This research demonstrates the potential of plant burial as a simple and reliable means of non-chemical weed management, and re-emphasises that, for weed control to be effective, the applied soil layer must cover the whole plant.     

小麦品种的抗赤霉病性与PGIP含量和分布的关系

研究了小麦品种的抗赤霉病性与多聚半乳糖醛酸酶抑制蛋白(PGIP)含量和分布的关系。斑点免疫结合测定(Dot-immunobinding assay)和蛋白质印迹分析(Western blotting analyze)结果显示,SW89-2589品种的PGIP含量高于89-106-2-9-24、80-8及3625品种;免疫组织化学定位表明,SW89-2589品种PGIP分布比80-8品种更为广泛。由此可见,小麦品种对赤霉病的抗性愈强,PGIP含量愈高、分布愈广。此研究结果为选育小麦抗性品种提供了一种新的鉴定方法。     

禾草灵防除春麦田禾本科杂草药效试验初报

1　材料与方法1 1　供试药剂供试药剂有 2 8%、36 %禾草灵乳油 (浙江一帆农药化工有限公司产 )、6 9%骠马水乳剂 (德国艾格福公司产 )。1 2　试验设计试验在西宁彭家寨乡彭家寨村小麦田进行 ,防除以野燕麦为主的禾本科杂草。设2 8%禾草灵ＥＣ每公顷商品量 (下同 )2 40 0ｍｌ、30 0 0ｍｌ、36 0 0ｍｌ,36 %乐草灵ＥＣ每公顷 1 80 0ｍｌ、2 340ｍｌ、2 70 0ｍｌ,6 9%骠马水收稿日期 :2 0 0 1- 0 6 - 0 4乳剂每公顷 750ｍｌ,以喷清水为对照 ,共 8个处理。小区面积 1 8ｍ2 ,重复 4次 ,随机排列。 5月 1 2日施药 ,施药前 4ｄ田间灌苗头水。喷…     

使阔得水分散粒剂防除麦田阔叶杂草试验简报

我市地处长江之滨，气候湿润，土壤墒情好。由于近年来推广稻套麦和免耕栽培技术，麦田杂草发生危害日趋加重，尤其是阔叶类杂草种类多、数量大，一般造成小麦减产３成以上。过去我市用于防除麦田阔叶杂草的药剂以使它隆为主，在冬前和春季两次使用，但仍不能控制阔叶类杂草的危害。因此，筛选麦田冬前一次用药全程控制草害的药剂显得尤为重要。２０００～２００１年我们选用６．２５％使阔得水分散粒剂防除麦田阔叶杂草，并对其防效及安全性进行了小区药效试验。材料与方法１，１ 供试药剂供试药剂有６，２５％使阔得水分散粒剂（法国安万…     

几种除草剂对稻茬麦田杂草的防除效果简报

应用灰色系统理论中的关联度分析法对7种除草剂在稻茬麦田的除草效果分析表明,去草隆、超级麦草宁、麦乐灵、麦草必净均具有良好的除草效果,华星麦保及异丙隆次之,以上除草剂均可在我区应用。     

不同番茄品种对5种植物双生病毒的抗病性鉴定

 由粉虱传双生病毒引起的番茄曲叶病［1］在我国最初仅分布在海南、云南、广东和广西,自2006年上海市和浙江省先后在番茄上发现番茄黄化曲叶病毒（Tomato yellow leaf curl virus,TYLCV）以来,该病害蔓延迅速,在多个省份的番茄上暴发成灾［2］。引起番茄曲叶病害的病原较复杂,在我国其主要病原为TYLCV、中国番木瓜曲叶病毒（Papaya leaf curl China virus, PaLCuCNV）、中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus, TYLCCNV)、泰国番茄黄化曲叶病毒（Tomato yellow leaf curl Thailand virus, TYLCTHV）和台湾番茄曲叶病毒（Tomato leaf curl Taiwan virus, ToLCTWV）［2~5］,而浙江省的主要病原为TYLCV和ToLCTWV。选育抗病品种是防治番茄黄化曲叶病最有效的手段。了解番茄品种对不同双生病毒的抗性,对因地制宜布局抗病品种具有重要意义。浙杂502、浙粉701、浙粉702是浙江省大规模种植的番茄品种,为了解这些品种对上述5种病毒的抗性,本研究利用5种病毒的侵染性克隆,在人工接种条件下,综合评定分析这3个番茄品种的抗病指标。     

汉阴县麦田杂草优势种群及防除

陕西省汉阴县麦田杂草有13科23种,其中分布范围较广、密度较大的有看麦娘、日本看麦娘、菵草、长芒棒头草等单子叶杂草和繁缕、猪殃殃、大巢菜、藜、刺儿菜等双子叶杂草.水稻茬麦田杂草发生危害重于旱地麦田,水稻茬麦田的优势杂草主要有看麦娘、繁缕、日本看麦娘、菵草,旱地麦田优势杂草主要有繁缕、猪殃殃、大巢菜、刺儿菜.针对麦田杂草的发生特点,提出协调农业防除与化学防除的综合治理策略,化学防除要针对麦田的不同杂草优势种群,合理选用除草剂,以达到综合除草效果.     

异丙隆＋苄嘧磺隆防除小麦田杂草试验报告

随着种植业结构的调整 ,麦作后茬作物种类增多 ,麦田化学除草剂绿、甲磺隆及其复配剂在土壤中残留期长 ,易对后茬作物造成药害 ,为此有必要选用新的药剂逐步替代绿、甲黄隆。异丙隆和苄嘧磺隆的复配剂将成为被选择的对象之一 ,因此 ,我们进行了异丙隆 苄嘧磺隆的配比筛选和用药适期试验 ,现将结果报道如下 :1　材料与方法1 1　供试药剂供试药剂有 :50 %异丙隆可湿性粉剂 (吴县农药厂产 )、1 0 %苄嘧磺隆可湿性粉剂 (江苏省激素研究所产 )、( 3) 70 %异·绿可湿性粉剂 (江阴农药厂产 )。1 2　试验处理1 2 1　药剂配比试验　 2 0 0 0年试…