Chemical Control of Herbicide Monosulfuron Plus Propazine 44% WP against Weeds in Millet Fields and Study on Factors Influencing Yield of Millet

[Objective] The paper was to resolve the poor efficacy or phytotoxicity problems in promotion of herbicide monosulfuron plus propazine 44% WP. [Method] Using orthogonal test and Duncan＇s new multiple range statistical analysis with four factors four levels and three factors two levels, the effects of factors such as herbi- cide dose, irrigation water volume, quality of soil preparation and soil moisture content on chemical control of monosulfuron plus propazine 44% WP against weeds and millet yield were compared in the test. [Result] Seven factors all had great impact on control effect of monosulfuron plus propazine 44% WP against weeds, of which her- bicide dose, irrigation water volume, quality of soil preparation and soil moisture content were the most important factors affecting millet yield. According to millet yield and economic benefit, the optimal scheme to ensure safe, efficient and economic control of monosulfuron plus propazine 44% WP against weeds was as follows： the dose of monosulfuron plus propazine 44% WP was 1 800 g/hm2, the soil was treat- ed after sowing and before seedling emergence; the soil should be smooth and sol- id; the soil moisture should reach 15%; the fields should not be irrigated after herbi- cide application, and the damage of weeds in millet fields could be effectively con- trolled within 45 d during high efficacy duration, especially the damage of dicotyledonous weeds. [Conclusion] The study provided useful information for comprehensive technology of weeds control and ensuring high yield and good harvest of millet.

Weed Occurrence and Chemical Control Test in Public Lawn of Suzhou Urban Area of China

Weed occurrence and damage in public green lawn of Suzhou urban area was assessed using five-grade weed visual survey method. The occurrence and damage of weeds in public green lawn of Suzhou City was very common. There were totally 67 species of weeds in green lawn, with the density of 6.5 plant/m^2, the relative abundance of 7.6%, the relative coverage of 10.3%, the relative height and the occurrence frequency of 100%, and the overall damage level of weeds was above the forth level. There were 14 species of major weeds causing damage, and 15 species of weeds were found to pose regional damage. Haloxyfop-R-methyl or Ping＇an-14 could be applied to control grassy weeds in clover lawns, with the herbicidal effect above 90%. MCPA, fluroxypyr, or clopyralid could be administra- ted alone to control broadleaf weeds in Cynodon dactylon or Festuca elata lawn, with the herbicidal effect above 85%. Since the weed species in weed communities of lawn were different, the types of herbicides should be targeted, or SD additives could be added to improve the herbicidal effect.

Weed Control Efficacy and Citrus Response to Flazasulfuron Applied Alone or in Combination with Other Herbicides

Field experiments were conducted to evaluate the phytotoxicity of flazasulfuron on citrus species and efficacy on weeds when applied alone or in combination with other herbicides. Grapefruit was the most sensitive and tangerine was the least sensitive to flazasulfuron. Injury to grapefruit was 70% with the application of flazasulfuron at 0.20 kg a.i. ha–1 at 60 DAT and was reduced (5%) when flazasulfuron at 0.05 kg a.i. ha–1 was tank mixed with glyphosate at 0.84 kg·a.i.· ha–1. Flazasulfuron alone at all rates did not control grass weeds and common ragweed. Florida/Brazil pusley was moderately controlled with high rates of flazasulfuron from 30 to 45 DAT;however, control did not exceed 75%. There was good control of Spanishneedles (78% - 85%) and horseweed (73% - 81%) with flazasulfuron at all rates at 30 DAT but control declined later in the season. Tank mix of flazasulfuron with glyphosate improved flazasulfuron efficacy on grass and broadleaf weeds. Flazasulfuron at 0.07 kg a.i. ha–1 plus glyphosate at 1.70 kg a.i. ha–1 was more effective in controlling grass weeds (83%) at 60 DAT and provided the highest control (79%) of Florida/Brazil pusley at 45 DAT. There was excellent control (75% to 94%) of Spanishneedles and adequate control of eastern black nightshade and common ragweed with flazasulfuron tank mixed with glyphosate or diuron. This study showed that flazasulfuron alone does not adequately control grasses and some broadleaf weeds in citrus and tank mixing it with glyphosate or diuron improved flazasulfuron’s efficacy. However, injury to grapefruit was observed at rates which effectively controlled weeds. Further studies are needed to determine the most suitable flazasulfuron rate that could be used to manage weeds in grapefruit.

Comparison of efficiencies and costs of different weed control methods in paddy production in Iran

Using of efficient and inexpensive method for weed control has an important role in increasing efficiency and reducing costs of production.In this study,field experiments were carried out to evaluate the efficiency and costs of several weed control methods in paddy production during summer in Mazandaran,the north province of Iran in 2011.Seven weed control treatments(T1 to T7)were applied at three stages of rice growth(20 and 35 days after transplanting and grain harvesting time).Weed density,weed dry weight,labor used and economical comparison were determined in the basis of a complete randomized block design with three replications.Results showed that there were no significant differences among efficiencies of six treatments(except for weedy check method(T6)treatment).The minimum weed density and dry weight were obtained at herbicide+hand weeding once(T5)and herbicide application once(T7)treatments during all three stages.The costs of weed control were different among the treatments.Selection of control method has an important role in reducing labor.Hand weeding twice method(T1),because of its high weeding cost,hard work and worker restriction in the required time,is not useful.Powered weeding twice method(T2),due to its zero environment pollution,reducing costs of weed control and high benefit/cost,is the best and most appropriate treatment.Amount of weed damage in weedy check method(T6)varied between 30.5%and 45.3%.

Weed control through allelopathic crop water extracts and S-metolachlor in cotton

Weeds are one of the most important biological constraint to cotton production,and result-ing in a yield losses of up to 90%.The evolution of hundreds of resistant weed species,the lack of new herbicide chemistries,and the increase in weed management costs are all mak-ing weed management more arduous for the growers.Hence,a field experiment was con-ducted to investigate the efficacy of allelopathic crop water extracts(ACWEs)alone and in combinaton with one third rate of S-metolachlor 717g ai.ha-1for effective weed man-agement in cotton.The treatments investigated were;weedy check,sorghum+brassica water extract(WE)at 1.5Lha 1,sorghum+sunflower WE at 1.5Lha-,sorghum+bras-sica+sunflower WE at 1.5Lha-1,sorghum+brassica WE at 15L ha-1+S-metolachlor at 717 g a.i.ha-l,sorghum+sunflower WE at 1.5L ha-1+S-metolachlor at 717 g a.i.ha-1,sor-ghum+brassica WE+sunflower WE at 1.5Lha-1+S-metolachlor at 717 gaiha-,and S-metolachlor at recommended rate of 2.15 kg ai.ha-1.Results revealed that pre-emergent application of sorghum+brassica water extract(WE)at 1.5L ha-1 was the best treatment in terms of effective dry biomass reduction(40%)of Trianthema portulacastrum and Cyperus rotundus,and increase in seed cotton yield(12%).The second best treatment was sorghum+sunflower WE at 1.5Lha-1+S-metolachlor at 717g ai.ha-1 with yield increase of 11%over the weedy control.In comparison,S-metolachlor at recommended rate 2.15kg a.i.ha-1 recorded only 4%decrease in weeds dry biomass reduction and 8%increase in seed cotton yield.Hence,it can be predicted that binary combinaton of sorghum and brassica WE at 1.5 Lha-1 or binary combination of sorghum+sunflower WE at 15Lha-1 with one third dose of S-metolachlor (717g aiha-l)can be used for effective weed management and increase in seed cotton yield.Furthermore,adoption of this technique will also reduce the herbicide application,which is not only benefcial for the ecosystem but,also minimize the evolution of herbicide-resistant weed species.

安徽省稻田杂草发生现状与防控对策

安徽省是我国水稻主产区之一,地处南北过渡带,滨江临淮,区位优势明显,地理、气候环境多样,不同水稻种植区逐渐形成以稗Echinochloa crus-galli、千金子Leptochloa chinensis、马唐Digitaria sanguinalis、杂草稻Oryza sativa等一种或多种恶性杂草为主的差异性分布群落,且伴随耕作及生产活动不断发生演替,对水稻的产量与品质构成严重威胁。目前安徽省稻田杂草防除仍以化学防控为主,单一化学除草剂常年高频超量使用现象突出,带来农业面源污染、农药残留、抗药性等一系列问题,使水稻稳产增收、杂草可持续防控等面临严峻的挑战。笔者在前期跟踪监测和调查走访的基础上,对安徽省稻田杂草发生、为害及防控现状进行了剖析,并针对安徽省当前稻田杂草防除中存在的问题提出部分对策和建议,以期为稻田杂草防控提供科学参考。

碎米知风草对不同环境因子的适应性及化学防治药剂的筛选

碎米知风草(Eragrostis japonica)是稻田恶性禾本科杂草之一。为明确影响碎米知风草种子萌发的主要环境因子,并筛选有效的化学防除药剂,采用培养皿法和盆钵法分别测定了温度、光照、pH、盐胁迫、渗透势、埋土深度对碎米知风草种子萌发的影响,并评价了27种稻田除草剂对碎米知风草的活性。结果表明,碎米知风草种子在20~40℃内均能萌发,恒温条件下最适萌发温度为35℃,变温条件下为35℃/25℃;其种子对光照较为敏感,黑暗条件下无法萌发;pH在4~10时种子萌发率在80.67%以上;随着NaCl浓度的升高,种子萌发率呈下降趋势,当NaCl浓度达到160 mmol·L^(-1)时种子停止萌发;碎米知风草种子对水势较为敏感,抑制萌发率50%时水势为-0.35 MPa;当埋土深度达到0.8 cm时可完全抑制种子萌发。活性结果表明,在推荐剂量下,土壤处理乙氧氟草醚、噁草酮、丁草胺、异噁草松、硝磺草酮、丙草胺、莎稗磷、二甲戊灵、仲丁灵、扑草净、环戊噁草酮11种药剂对碎米知风草的抑制效果较强,鲜重抑制率在96.28%以上;茎叶处理药剂噁唑酰草胺、禾草丹、敌稗、吡唑喹草酯、苯丙草酮5种药剂对碎米知风草的鲜重抑制率在92.16%~99.36%。该结果可为稻田碎米知风草的化学防治提供参考依据。

不同除草配方对大豆田抗性反枝苋防除效果的研究

为探索黑龙江省北部大豆主产区抗性反枝苋最佳防治方法,文章优选4种苗前封闭除草剂及4种苗后茎叶除草剂进行田间防效试验,分析不同药剂组合对反枝苋的防除效果。结果表明,苗前封闭处理,90%乙草胺EC 1800 g a.i./hm^(2)和30%丙炔氟草胺SC 51 g a.i./hm^(2)对反枝苋防效较高,施药45 d后,反枝苋防效为87.79%;苗后茎叶处理,250 g/L氟磺胺草醚AS(科坦见露灵)750 g a.i./hm^(2)+助剂(伴豆一生)2000 m L/hm^(2)对反枝苋的防效较高,且持效期长;苗前封闭结合苗后茎叶处理,90%乙草胺EC 1800 g a.i./hm^(2)+30%丙炔氟草胺SC 51 g a.i./hm^(2)+250 g/L氟磺胺草醚AS 500 g a.i./hm^(2)+480 g/L灭草松AS 1680 g a.i./hm^(2)+助剂(迪增)225 m L/hm^(2)对反枝苋的防效达93%,且持效期长。大豆田抗性反枝苋防控方法中,苗前封闭处理防效显著高于苗后茎叶处理。生产中建议以苗前封闭除草为主,结合苗后化学除草、轮作等措施综合防治反枝苋。

北苍术苗期除草剂的筛选

人工种植管理过程中杂草影响着北苍术苗期生长发育,寻找安全、高效、广谱的北苍术苗期除草剂。选用108 g/L高效氟吡甲禾灵乳油、250 g/L氟磺胺草醚、10%苯磺隆三种除草剂,通过外源喷施大田主要杂草(中华苦荬菜、狗尾草和马齿苋)和北苍术幼苗,筛选出适宜的除草剂浓度及合适配比,统计不同处理配比下对杂草和北苍术苗的防除效果。结果说明,108 g/L高效氟吡甲禾灵乳油对禾本科狗尾草防除效果好;250 g/L氟磺胺草醚对三种杂草防除效果均有效但对北苍术有损伤;10%苯磺隆对菊科中华苦荬菜防除效果好;采用0.023 mL/m^(2)108 g/L高效氟吡甲禾灵乳油+0.024 mL/m^(2)250 g/L氟磺胺草醚对北苍术伤害最小,对杂草防除效果最好。研究筛选出的除草剂可为北苍术的大田种植提供一定的理论指导与参考价值。

封闭式除草剂苗后喷施对小麦生长和杂草的影响

为探究封闭式除草剂苗后喷施对小麦生长和杂草的影响,以周麦22为试验材料,设置砜吡草唑用量125(T1)、250(T2)、500(T3)、1000(T4)、2000(T5)g a.i./hm^(2)和氟噻草胺用量184.5(T6)、369(T7)、738(T8)、1476(T9)g a.i./hm^(2)9个喷药处理和1个空白(清水)对照,研究不同除草剂对小麦光合特性、叶绿素SPAD值、光合有效辐射(IPAR)、叶面积指数(LAI)、鲜质量的影响及对杂草的化除效果。结果表明:T1、T6处理下小麦叶片的净光合速率高于对照,9个处理蒸腾速率均低于对照,T6、T1处理数值较大,气孔导度T1处理最大;胞间CO_(2)浓度T9处理最大,T1处理最小。在除草剂施用21 d时,T1处理SPAD值与对照差异有统计学意义。T1、T2、T3、T6、T7处理下,小麦IPAR和LAI均高于对照,且以T1处理下值最大,较对照分别增加18.37%、37.77%,T2次之。砜吡草唑施药剂量在125、250 g a.i./hm^(2)时(T1和T2)对小麦株高和鲜质量没有显著性影响;当剂量>250 g a.i./hm^(2)时,则会出现抑制症状,氟噻草胺不同用量小麦株高和鲜质量均受抑制。可见,T1和T2处理对小麦生长发育影响较小。T4、T5和T93个处理对所试杂草鲜质量防效均高于95%,T1和T62个处理对野燕麦的防效不明显。考虑到对小麦生长安全和用药成本,在对节节麦和野燕麦鲜质量防效达到50%~95%且对其余供试杂草鲜质量防效均高于95%的6个处理(T2、T3、T4、T5、T8、T9)中,推荐T2处理用于麦田苗后喷施。

农田化学除草与可持续发展农业

本文在概述了农田杂草危害性的基础上，总结了我国农田杂草综合治理，尤其是农田化学除草的现状和成就，并从杂草群落演替加速、长残效除草剂药害严重、施药技术滞后、抗药性杂草正在形成、以及与发达国家在使用技术上的差距等方面提出了存在的问题。建议在除草剂作用机理、混合制剂、剂型、增效作用等方面加强研究，使农田化学除草剂在可持续发展农业中发挥更加积极的作用。

东部地区大豆田杂草种群演变趋势及其化学防除

根据１９８２、１９９２ 和 １９９７ 年对黑龙江省东部地区大豆主要种植区杂草的调查结果，明确了该地区大豆田杂草种群及群落演变趋势及影响种群演变的因素。介绍了大豆田除草的关键时期、常用除草剂种类及其使用技术。

中国化学除草问题与对策

我国化学除草存在的问题是除草剂喷洒器械落后、除草剂药害发生频繁、长残留除草剂危害严重、农田杂草群落演替加快,难治杂草危害加大了化学除草工作难度。建议加强农药和施药器械的研制、生产、管理和使用技术的研究、普及,加强长残留除草剂科学使用和管理,加强果树、蔬菜、经济作物化学除草使用技术的研究。除草剂产品开发要适合国情,重视除草剂的安全性,促进我国化学除草的发展。

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。

油菜田杂草发生规律及化学防除技术

总结分析了湖北省油菜田杂草的发生规律及危害,种类和群落变化,明确了油菜田杂草的发生高峰主要在冬前10月初至11月中旬,冬前杂草占油菜整个生育期杂草总量的70%～80%,对油菜的生长和产量影响极大,是杂草防除的关键时期;较详细地叙述了20种除草剂的防效和使用方法;并讨论了油菜田杂草化学防除存在的主要问题与对策。

冷季型草坪杂草化学防除技术研究

1997年开始进行冷季型草坪杂草化学防除技术研究 ,阔叶杂草在 2～ 4叶期用 72 %的2 ,4 - D丁酯乳油防除 ,防除效果可达 92 .4 % ;禾本科杂草用拉索、扑草净、乙草胺、氟乐灵进行播前诱杀防除 ,防除效果分别可达 84 .6%、65 .9%、5 1.8%和 4 5 .0 %。

成都市城市绿地杂草调查及化学防除研究

分冬春季和夏秋季在成都市所辖的区市县的城市绿地进行了杂草发生情况调查,结果表明:成都市绿地全年发生杂草种类计46科192种;冬春季优势杂草有酢浆草、繁缕、黄鹌菜、小飞蓬、天胡荽、通泉草、碎米荠、棒头草等;夏秋季优势杂草有马唐、水蜈蚣、水花生、酢浆草、天胡荽、牛筋草、小飞蓬、马兰、辣子草等。在麦冬绿地,可用草甘膦615～861g/hm2防除各种杂草。在红叶石楠绿地杂草苗后除草,可用草铵膦600～900g/hm2防除各种杂草,注意定向喷雾。在红叶石楠移栽前或人工除草之后杂草芽前,可用33%二甲戊灵EC(643.5g/hm2)或24%乙氧氟草醚EC(288g/hm2)防除各种杂草。在狗牙根草坪,可用100g/L三氟啶磺隆钠盐油悬浮剂(22.5～30a.i.g/hm2)或25%啶嘧磺隆WDG(56.25a.i.g/hm2)防除各种杂草。

四川国际高尔夫球场草坪杂草及其化学防除研究

1997～ 1999年的调查结果表明 :四川国际高尔夫球场草坪杂草有 19科 4 0种 ,其中数量最多 ,危害较严重的杂草 5种 :黄花酢浆草、天胡荽、香附子、水蜈蚣和马唐 ,占所有杂草数量的 95%以上。化学防除试验结果表明 :用百草敌 1.0 g/ 10 m2 +2 ,4 - D0 .2 g/ 10 m2可有效防除黄花酢浆草等阔叶杂草 ;用苯达松 1.0 g/ 10 m2 +2甲 4氯 1.5g/ 10 m2可有效防除香附子等莎草科杂草 ;用 dithiopyr0 .12～ 0 .2 4 g/ 10 m2可有效防除马唐。

南京市草坪夏季杂草分布特点及防除措施研究

用样线法调查了南京市绿色草坪共 2 7个样点的杂草发生及分布情况 ,并用系统聚类法分析比较了各草坪杂草群落的发生及分布特点。调查结果表明 ,南京市草坪杂草的发生和分布与草坪所处地理位置、土壤水分条件及管理水平有密切关系 ;其中 ,地理位置是草坪杂草分布差异的间接原因 ,杂草种类的多少及每种杂草的数量与管理水平有直接的关系。根据聚类分析结果可将全部样点分成 3个聚类群——第一聚类群是以三叶草 (阔叶类 )为优势种的杂草群落 ;第二聚类群是以香附子 (莎草类 )为优势种的杂草群落 ;第三聚类群是以马唐 (禾草类 )为优势种的杂草群落。同时 ,针对南京市主要草坪种类进行了化学除草剂的筛选和复配剂的研制试验。

草坪禾本科杂草的化学防除技术

在 2 0 0 0～ 2 0 0 1年 2a间 ,用 6种禾本科除草剂对草坪禾本科杂草进行防除试验 ,结果表明 :禾耐斯作为芽前除草剂的效果比较好 ,对狗尾草、马唐、看麦娘和早熟禾的出芽抑制率均达到 10 0 % ;5种茎叶处理剂都是防除禾本科杂草十分有效的茎叶处理剂 ,对几种主要的禾本科杂草的防效都很高。