旱改水稻田杂草群落的演替

连续旱作的田块改种水稻后 ,随着改水年限的增加 ,土壤保水性得到改善 ,稻田杂草群落的物种组成逐渐与老稻田的杂草群落接近。与老稻田的相比 ,旱改水第 1年稻田杂草群落的相似系数为 0 .4 8,第 2年的提高至 0 .6 9,第 3、4年的则上升至 0 .84和 0 .83;群落多样性指数也逐年增加 ,旱改水第 1、2、3年 ,香农 -威纳指数分别为 1.8991、2 .2 785、2 .3915 ,辛普森指数分别为 0 .82 96、0 .85 6 0、0 .880 8;群落均匀性指数也有所提高 ,香农 -威纳指数分别为 0 .790 2、0 .7883、0 .82 74 ,辛普森指数分别为 0 .912 6、0 .90 6 4、0 .932 6。田间使用一次性除草剂(苄·乙 )后可使杂草群落的演替加快。在当前生产条件下 ,旱田改种水稻连续 3～ 4年后 ,稻田中杂草群落面貌基本与典型的稻田杂草群落相似。     

浙江省稻田杂草群落及其演替

浙江省稻田杂草优势群落，早稻为稗草群落，晚稻田为阔叶草群落。随着化学除草剂使用的延长，稻田杂草群落的演替速度加快，群落结构中的多年生难除草四叶萍、水莎草、双穗省稗和空心莲子草的发生频度明显增加。     

江苏省稻田杂草群落演替趋势及防除对策

江苏省稻田杂草有６９种，分属２７科，重要恶性杂草有稗，扁秆蔗草，矮慈姑，眼子菜。水莎草，鲤肠等１０多种，由这些杂草组成不同的主要杂草组合８个，由于化学除草的普及和连年使用单一除草剂，以及轮，耕作制度，栽培方式变革等原因，造成阔叶杂草上或，特别是多年生恶性杂草上升、稗草发生波动的群落演替趋势。稻田杂草的防除对策应在掌握杂草群落组合分布的基础上，以应用一次性高效，广谱复配方除草剂为主体，结合一定的农世     

四种除草剂对稻田杂草防除试验

四种除草剂对稻田杂草防除试验陆兆庆（邕宁县四塘镇农技站５３０２１６）化学除草作为降低劳动强度，提高生产效率的主要手段，得到了广泛的推广应用。当前，市场上的稻田除草剂种类较多，为了进一步了解各种除草剂对稻田杂草的防除效果，找出适合本地情况的使用技术，作...     

春麦田除草剂的应用与杂草群落演替

作者采用定点定位试验,对春麦田除草剂应用与杂草群落演替趋势进行研究。结果表明:在杂草群落多样性麦田,小麦连作并分别连续5年施用同一种除草剂,原杂草群落中占优势的靶标杂草得以控制,而非靶标杂草和抗、耐药性杂草因失去竞争和制约对象而猖獗发展,发生量较原来增加几倍至几十倍,并形成优势种群,对小麦造成新的更严重的危害。一种除草剂在同田块连续施用4年,由于杂草群落演替,抗、耐药杂草兴起,除草效果显著下降而失去其使用意义。作者提出除草剂配套使用、轮用、混用等措施,并配合以合理的轮作制度,以减轻杂草群落长期受到单一的定向选择性压力。     

几种除草剂对稻田杂草的防除效果

选择田草绝、精克草星、稻草隆、草克净、巧手等进行田间试验，结果表明，5种药剂均具有良好的防效和安全性。     

黑龙港地区旱田杂草群落演替

本文提出黑龙港地区旱田中作物－杂草群落的季相变化和群落演替现象。群落演替在不同作物农田有所区别，它是多种条件综合作用的结果。研究旱田杂草群落演替的意义，在于月目的地通过人为活动，干扰杂草群落演替方向，使其朝着有利于获得高产和对杂草的综合治理方面发展。     

沈阳地区水稻田杂草群落演替及成因

2003-2004年调查结果表明，沈阳地区水稻田常见杂草有16科38种，与1990～1993年杂草普查资料对比，杂草种群发生了改变。稗草、野慈姑、狼把草、浮萍、水绵等已成为主要危害杂草。除草剂的使用、田间管理、气候因素是杂草群落演替的主要原因。     

除草剂防除抛秧稻田杂草的效果

水稻抛秧省工、节本又省水,作为轻型栽培技术的主要方式之一,迅速在我市大面积推广。由于其栽培管理条件不同于常规移栽稻田,因此杂草的种类及其数量明显多于常规稻田。为了进一步明确抛秧稻田杂草的化除技术及其对水稻的影响,1997年我们在金沙镇马北村7组进行了多种除草剂防除抛秧稻田杂草试验。1材料与方法1．1供试材料30％丁·苄WP（如东农药厂产）,60％丁草胺EC南通化工厂产）,36％二氯·苄WF（常州农药厂产）,96％禾大壮EC（捷利康公司产）,36％水旱灵EC（如皋化工厂产）,90％高杀草丹EC（日本住友公司产）,10％苄黄隆…     

上海市水稻田杂草种类组成及群落特征

为明确上海市水稻田杂草种类组成及其群落结构,采用倒置"W"取样法对上海市水稻田杂草进行了调查。结果表明,上海市水稻田杂草共有55种(含变种),隶属于16科35属,其中禾本科和莎草科杂草种类最多。优势杂草有无芒稗、千金子、多花水苋、耳叶水苋等4种,区域性优势杂草有马唐、杂草稻、鳢肠、假稻、稗、空心莲子草、水莎草等7种,这11种杂草是上海市水稻田杂草群落的重要建群种,此外常见杂草有8种,一般杂草有36种。从杂草区域分布来看,上海西部地区水稻田杂草群落的物种多样性最高,但优势种集中性最低;东部地区的物种丰富度和优势种集中性均最高;江中沙洲地区的物种丰富度和多样性均最低。从相似性指数和聚类分析来看,上海市水稻田杂草群落可划分为3组,其中东部地区和江中沙洲地区各一组,西部地区和中部地区的杂草群落结构最类似,为一组。水稻田杂草种类及其群落发生特点与地理区域、耕作制度、栽培方式和除草剂种类等多种因素相关。     

Influences of long‐term different types of fertilization on weed community biodiversity in rice paddy fields

In order to provide a scientific basis for developing integrated weed management strategies in rice paddy fields, this study investigated the influences of different types of fertilization on weed biodiversity. The experiment was conducted at Long‐term‐located Monitoring Station for Soil Fertility, Agricultural Science Academy, of Jiangxi Province, China. Five fertilization treatments were set: no fertilization (NOF), PK, NP, NK, and NPK. The results showed that the influence of different fertilization treatments on weed community traits followed the models PK > NOF > NK > NP > NPK for species richness, PK > NOF > NK > NP > NPK for species diversity, NPK > NP > NK > NOF > PK for community dominance, and PK > NOF > NK > NP > NPK for community evenness. Under NPK (i.e. balanced fertilization), the weed species diversity and richness and weed community evenness were the lowest. The principal component analysis showed that the weed community was divided into three groups: (i) NK and a part of NOF; (ii) NP and NPK; and (iii) PK and NOF. The correlation analysis indicated that the influence of each macro‐element on the weed community followed the model N > P > K. The organic content in the paddy soil might have played an equally important role with the amount of available N in determining the weed community's characteristics. Regarding the way by which N, P, and K influenced the weed community, the amount of available P and K mainly influenced the organic content, while the amount of available N influenced both the organic content and light transmittance within the canopy, thereby enhancing the capacity of rice to compete with weeds.     

河北省玉米田杂草组成及群落特征

采用倒置“W”取样法对河北省玉米田杂草进行了调查,以明确田间杂草的种类组成及群落结构.结果表明,河北省玉米田杂草有136种（含变种）,隶属于34科、97属,其中优势杂草有马唐、反枝苋、稗、马齿苋、藜、狗尾草、铁苋菜、刺儿菜、田旋花等9种,区域性优势杂草有10种,常见杂草有21种,一般杂草有96种.发生优势度较大的杂草为马唐、反枝苋、稗、马齿苋、藜、狗尾草等,是构成各地区田间杂草群落的优势种.张家口地区主要形成反枝苋＋狗尾草＋灰绿藜＋藜为主的杂草群落,承德地区为马唐＋稗＋反枝苋＋藜,唐山-秦皇岛地区为马唐＋马齿苋＋鸭跖草＋稗＋反枝苋,石家庄地区为马唐＋牛筋草＋铁苋菜＋马齿苋.张家口和承德地区玉米田杂草群落的物种丰富度、多样性及均匀度较其它地区高,而优势度较低.从群落相似性来看,石家庄与唐山-秦皇岛地区群落结构最为相似.地理环境、气候条件及控草措施的不同,可能是导致玉米田杂草发生及群落组成产生差异的原因.     

不同轮作制度对定西地区农田杂草群落的影响

为探讨不同轮作制度对定西地区农田杂草群落的影响,采用倒置"W"九点取样法,调查了定西地区7种不同轮作制度下田间杂草的种类、数量、地上生物量等。在试验田发现11个科共15种杂草;从杂草发生密度、地上生物量上看,苦苣菜、藜是农田优势杂草,防除的目的杂草;不同轮作田的杂草群落由优势杂草组成;从不同轮作田杂草群落的物种多样性来看,马铃薯胡麻轮作马铃薯小麦轮作胡麻小麦轮作胡麻连作小麦胡麻轮作小麦马铃薯轮作胡麻马铃薯轮作;对不同轮作田杂草群落进行聚类,可分为四类。通过对不同轮作田中杂草的密度、地上生物量和综合优势度比的综合分析,可以看出胡麻连作、小麦胡麻轮作、马铃薯胡麻轮作、小麦马铃薯轮作中杂草的危害性较大。马铃薯小麦轮作、胡麻小麦轮作和胡麻马铃薯轮作对杂草有一定的控制作用。     

3种除草剂对水稻旱直播阔叶杂草防效及安全性研究

为明确不同除草剂茎叶处理对旱直播水稻田旱生阔叶杂草防除及安全性的影响,采用随机区组试验设计,选用30% 2,4-滴丁酸钠盐AS、84%氯酯磺草胺WG、480 g/L灭草松AS 3种除草剂在水稻4叶期、5叶期施用,施药后每间隔7 d测定杂草株防效、鲜重防效和水稻目测药害,同步测定水稻生长指标和抗逆酶活性。结果表明:30% 2,4-滴丁酸钠盐AS 900.0 g/hm2在水稻4叶期的杂草防效最佳,第28天杂草株防效及鲜重防效仍可达93.55%和96.42%,且对大龄鸭跖草防效显著,施药后水稻生长与人工除草相比无显著差异。叶片SOD、POD活性和MDA含量均先升后降,至施药后28 d恢复正常。30% 2,4-滴丁酸钠盐AS 900.0 g/hm2可高效防除阔叶杂草,该药剂在水稻4叶期和5叶期施用对旱直播水稻安全。     

Weed flora distribution in Greek cotton fields and its possible influence by herbicides

A weed survey methodology was used for 2 years in three provinces in Greece to determine the abundance and spatial distribution of weeds in cotton (Gossypium hirsutum L.) fields. Based on a stratified random sampling procedure, the most frequently occurring weeds were counted in 150 cotton fields. The field surveys were conducted late in the growing season; hence, the weed populations consisted of species that had been present during the critical competitive period for the crop and may have contributed to yield losses.Solanum nigrum was the most abundant weed in the surveyed fields of the southern province, followed byCyperus rotundus, Convolvulus arvensis, Xanthium strumarium, Chrozophora tinctoria andCynodon dactylon, in descending order. The ranked weed flora in the fields of the northern province was differentiated, suggesting the geographical distribution of weed species. The weedsDatura stramonium andS. nigrum were recorded in high abundance and followed byAmaranthus spp.,Abutilon theophrasti, Portulaca oleracea, Chenopodium album andXanthium spinosum, in descending order. Although the use of preplant incorporated herbicides is the dominant practice in cotton cultivation, certain weeds continue to spread in increasing densities. http://www.phytoparasitica.org posting July 26, 2005.     

河南省小麦田杂草组成及群落特征

为明确河南省小麦田杂草的种类组成和群落特征,采用倒置"W"9点取样法对河南省36个区县的小麦田杂草进行了调查。结果表明,小麦田杂草有77种,隶属于20科65属,其中以禾本科、菊科、十字花科为主;优势杂草有10种,分别为播娘蒿、野燕麦、荠菜、猪殃殃、婆婆纳、麦家公、麦瓶草、节节麦、雀麦、硬草;常见杂草有28种,一般性杂草有39种。从杂草区域分布来看,伏牛山区小麦田杂草群落的物种丰富度、多样性最高,杂草有49种,Shannon-Wiener指数最高,为2.94;豫南平原区Pielou指数最小,为0.75,Simpson指数最高,为0.098,优势杂草突出。聚类分析结果表明,河南省小麦田的杂草群落可以划分为3组,第1组为豫北平原区、豫南平原区和伏牛山区的杂草群落,第2组为南阳盆地区和桐柏大别山区的杂草群落,第3组为太行山区的杂草群落。     

Change in weed control studies of rice paddy fields in Korea

This paper was reviewed on the research status of weed control according to cultivating patterns of rice in Korea. Weed control study in a nursery bed was chiefly carried out to control the species of barnyardgrass at the times of machine transplanting. Propanil and nitrofen were applied successfully in wet-nursery beds, and chlornitrofen and pyrazolate/butachlor were also successfully applied in protected semi-irrigated rice nursery beds in the 1970s. Sequential application of herbicides in the mid-1980s has resulted in the end of hand weeding. In machine transplanting, basic research such as the selection of herbicides was conducted in the early 1970s, and its related research including crop injury, seedling age, and reaction of cultivars were done in the late 1970s to early 1980s. Effects of the continuous application of herbicides and its methods of labor saving for rice cultivation were studied in the mid to late 1980s. When the rice planting methods were newly established, such as transplanting when seedlings were 10-days-old and direct seeding from the early 1990s, weed control research relating to herbicides was carried out (e.g. herbicide registration, crop injury, water management, appropriate application time, and neighboring application with insecticide). Weed control for the dill seeding of fields in wetted and reclaimed saline land have been experimented with, particularly in terms of the physio-ecological characteristics and the control of problematic weeds, and the resistance of weeds to herbicides was also investigated systematically.     

窄行平作密植大豆田杂草群落组成与发生特点

通过W曲线五点取样法,调查窄行平作密植大豆田的杂草群落组成和发生特点。调查结果表明,窄行平作密植大豆田杂草群落组成复杂,为多种优势杂草群落,不同地区杂草群落组成不同;种群密度大,发生密度200株/m左右。发生特点表现为:杂草群落按逻辑斯蒂(Logistic)曲线模式增长;发生较集中,发生高峰期仅10 d左右;杂草发生高峰期比大豆出苗高峰期早4~5 d。     

不同除草剂对11种冬小麦田阔叶杂草的防除效果比较

小麦田除草剂的长期使用,造成麦田杂草群落发生变化。为建立不同区域优势杂草种类的化学防除技术,本研究采用室内盆栽法测定了14种除草剂对11种冬小麦田阔叶杂草的防除效果。结果表明,灭草松可以较好地防除冬小麦田野老鹳草、牛繁缕、大巢菜、紫堇、小藜、阿拉伯婆婆纳、播娘蒿、猪殃殃、麦家公等阔叶杂草;吡草醚对野老鹳草、牛繁缕、小藜、阿拉伯婆婆纳、播娘蒿、猪殃殃、麦家公、荠菜等8种杂草防效突出。辛酰溴苯腈可很好地防除牛繁缕、大巢菜、小藜、阿拉伯婆婆纳、播娘蒿、麦家公等6种阔叶杂草;唑草酮对野老鹳草、牛繁缕、阿拉伯婆婆纳、播娘蒿、猪殃殃等5种杂草防效突出。这4种除草剂及其适用浓度与其他供试药剂相比杀草谱更为广泛,对阔叶杂草防效较好。根据不同区域优势杂草种类,合理选用高效除草剂进行防除。