17种除草剂对小麦田猪殃殃的防除效果

为筛选出对麦田恶性杂草猪殃殃防效较好的药剂,对17种除草剂开展了温室盆栽试验和田间小区试验。温室盆栽试验中,200g·L~(-1)氯氟吡氧乙酸乳油和25%灭草松水剂对猪殃殃有较好的抑制作用,试验剂量下鲜重抑制率均达100.00%。田间小区试验中,对猪殃殃防效最好的是80%唑嘧磺草胺水分散粒剂,用药25.00g(a.i)·hm~(-2)后30d对猪殃殃的株数防效为85.08%,药后60d的株数防效和鲜重防效则达100.00%;其次为50g·L~(-1)双氟磺草胺悬浮剂、200g·L~(-1)氯氟吡氧乙酸乳油。     

防除马铃薯田阔叶杂草除草剂的筛选及对马铃薯安全性

为了筛选出对马铃薯田阔叶杂草防效较高的药剂,选择7种目前常用的除草剂进行大田试验。试验结果表明,播后苗前土壤处理除草剂50%乙草胺EC、33%二甲戊灵EC、50%利谷隆WP和33%二甲戊灵EC+50%乙草胺EC,在3.75 L/hm2、4.5 L/hm2、4.5 kg/hm2和2.25 L/hm2+1.875 L/hm2剂量下,对马铃薯安全,且对阔叶杂草具有一定的防除效果,其中50%利谷隆WP具有显著防效,药后60 d对阔叶杂草的株防效和鲜重防效分别达到96.70%和98.34%;苗期茎叶处理除草剂56%2甲4氯钠盐WP、70%嗪草酮WP以及二者的配比混剂组合70%嗪草酮WP+56%2甲4氯钠盐WP,在1.8 kg/hm2、1.2 kg/hm2、0.45 kg/hm2+1.35 kg/hm2、1.05 kg/hm2+0.75 kg/hm2剂量下,对马铃薯安全,且对阔叶杂草具有较高防效,药后45 d株防效在71.21%~100.00%,鲜重防效在81.52%~100.00%。     

阔世玛的麦田杂草防效及对小麦田间透光率和产量的影响

为给阔世玛可分散油剂的推广应用提供依据,通过大田喷施试验,研究了12 g·L-1阔世玛对小麦田间杂草的防效及对小麦田间透光率和产量的影响.结果表明,阔世玛时小麦田婆婆纳、野燕麦、大巢莱、猪殃殃、野油莱等杂草有较好的防除效果,可明显降低杂草株高、鲜重及养分和水分含量.抑制杂草生长,显著增加小麦田间的透光率和小麦产量.综合来看,阔世玛在麦田杂草处于2～6叶期时喷施,喷施剂量以8.1～13.5 g(a.i.)·hm-2为宜.     

适于无人机喷施的花生田苗后除草剂配施技术研究

为探索在花生田应用无人机喷洒茎叶处理除草剂的可行性,本研究以人工背负式喷雾器喷施作为对照,选用4种除草剂并设置不同配比,对四旋翼无人机喷施除草剂的防效进行评价。结果表明,在所选药剂推荐剂量下,无人机施药对花生安全,对杂草的综合防效为73.6%～97.6%。无人机施药对杂草防效及对花生安全性与对照间无显著性差异,但喷施除草剂药量及用水量缩减至对照用量的1/30。田间杂草可使花生单株荚果数显著降低,进而造成产量下降,其中苘麻的影响效果最为明显。因此,在以苘麻为优势种群的花生田,推荐480 g/L灭草松水剂与960 g/L高效氟吡甲禾灵乳油桶混后运用无人机喷洒,防效可达97.6%,增产1.63%～229.89%。     

除草剂混配施用对棉田常见杂草的防除效果

为了检验除草剂防除棉田杂草效果,以三氟啶磺隆、嘧草硫醚和精喹禾灵之间不同剂量的混配施用.试验表明：三氟啶磺隆和精喹禾灵两种混用及三氟啶磺隆、嘧草硫醚和精喹禾灵3种混用均对棉田杂草都有较好的防除效果.施药后7天杂草表现药害症状.施药后20天,三氟啶磺隆与精喹禾灵两种除草剂混用,随着三氟啶磺隆用量的增加对禾本科杂草的防效由89.2％增加到95.3％,对阔叶类杂草的防效由86.3％增加到94.9％,总体株防效由87.8％增加到95.2％;三氟啶磺隆与精喹禾灵、嘧草硫醚混剂3种除草剂混用,在精喹禾灵用量相同的条件下,增加三氟啶磺隆或嘧草硫醚的用量,对禾本科杂草、阔叶类杂草、杂草总体株防效均提高.施药后40天的株防效和鲜重防效均80％以上,说明混配药剂的持效期较长.     

棉田外来入侵杂草黄顶菊的化学防除

 研究了棉田7种土壤除草剂和7种茎叶除草剂对黄顶菊的防效。结果表明：土壤除草剂室内生测以48%仲丁灵EC 200～400倍防效最佳,90%乙草胺EC 200～400倍、50%敌草胺WP 133～400倍也表现出较高防效。田间土壤处理以96%精异丙甲草胺EC 720.0～1440.0 g·hm^-2处理防效最佳,48%氟乐灵EC、90%乙草胺EC、50%扑草净WP也表现出较高防效。茎叶除草剂田间试验以25%氟磺胺草醚AS 281.5～563.1 g·hm^-2防效最佳,20%百草枯AS中高浓度、75%三氟啶磺隆钠盐WP、75%嘧硫草醚WP和41%草甘膦AS也具有较高防效。     

20%氨氯吡啶酸·二氯吡啶酸·烯草酮可分散油悬浮剂防除油菜田杂草的效果

为明确新型吡啶类和环己烯酮类除草剂复配制剂对油菜田杂草的防控效果,指导新型除草剂在油菜田的合理使用,通过田间试验研究了20%氨氯吡啶酸·二氯吡啶酸·烯草酮可分散油悬浮剂对油菜田主要杂草的防除效果,以及杂草防除后对田间光照和杂草氮、磷、钾及水分累积的影响。试验结果表明,施用20%氨氯吡啶酸·二氯吡啶酸·烯草酮可分散油悬浮剂防除油菜田杂草效果显著,对菵草、大巢菜、看麦娘、牛繁缕等单双子叶杂草均有良好防效,总草鲜重防效可达88. 7%～98. 0%,显著优于两种对照药剂。杂草防除后,显著降低了杂草对田间氮、磷、钾和水分的消耗,有效地改善了田间光照和水肥条件。20%氨氯吡啶酸·二氯吡啶酸·烯草酮可分散油悬浮剂处理的油菜产量达到2 626. 26～2 836. 26kg/hm^2,增产效果显著,产量较空白对照增加18. 2%～27. 9%,增收2 173. 5～3 307. 5元/hm^2。研究结果表明,20%氨氯吡啶酸·二氯吡啶酸·烯草酮可分散油悬浮剂在油菜田有良好的应用前景,推荐剂量为每公顷使用有效成分225～300g。     

小麦纹枯病田间药剂防治技术研究

通过田间小区试验,比较了不同杀菌剂与施药技术对小麦纹枯病的田间防效.结果表明,单剂拌种对小麦纹枯病的防效以5％的适乐丹最好,小麦拔节期其防效为72.75％,且持效期长;混剂拌种以混剂3(戊唑醇+三唑酮WP1∶1)按种子重量的0.04％拌种防效最好,小麦拔节期其防效为55.94％;小麦拔节期药剂喷雾的防效以混剂5(戊唑醇+丙环唑EC1∶1)按900 mL·hm-2喷雾的防效最好;药剂不同处理技术对小麦纹枯病和小麦白粉病的防效均以混剂1(三唑酮WP+福美双WP1∶9)按种子重量的0.04％拌种加混剂5分别在小麦拔节期和孕穗期各喷雾1次的防效最好,该处理措施在小麦腊熟期对小麦纹枯病的防效为77.40％,在孕穗期对小麦白粉病的防效为95.28 ％.综合各药剂在小麦不同生育阶段的防效,药剂拌种+拔节期喷雾+孕穗期喷雾的药剂防治策略总体控病效果最好,增产效果明显;其次是药剂拌种+拔节期喷雾.     

2种组合药剂对水直播稻田杂草茎叶化除试验

为了达到高效和节本降耗的目的,本试验选择了2组药剂于播后13 d进行茎叶化除试验,一次性地防除水直播稻田内杂草。试验表明:20%二氯喹啉草酮SC 200 m L/667 m2+20%氰氟草酯EC 50 m L/667 m2+75%氯吡嘧磺隆WP 2 g/667 m2作为水直播稻田杂草茎叶处理组合药剂,对水稻安全性好,对稗草、千金子和扁秆藨草的防效较好,可有效防除田间杂草。     

噻苯隆和乙烯利与噁草酸复配对棉田杂草的防除效果

为科学使用除草剂、预防杂草抗药性的产生，研究10%（质量分数，下同）噁草酸乳油以田间推荐剂量60.0 g·hm^－2（有效成分用量，下同）和45.0 g·hm^－2（田间推荐剂量减量25%）分别与不同剂量的50%噻苯隆悬浮剂（37.5、75.0、150.0 g·hm^－2）、41%乙烯利水剂（400.0、600.0、800.0 g·hm^－2）混配对棉田杂草的防除效果。结果表明：噻苯隆悬浮剂75.0 g·hm^－2和150.0 g·hm^－2与45.0 g·hm^－2的噁草酸乳油混配使用，药后15 d的株防效分别达到93.3%和96.5%，极显著高于噁草酸乳油单剂处理的52.3%；药后45 d的株防效分别为93.5%和98.3%，显著高于噁草酸乳油单剂处理，质量防效分别提高19.3和24.4百分点。600 g·hm^－2和800 g·hm^－2乙烯利水剂与45.0 g·hm^－2的噁草酸乳油混配使用，药后15 d、30 d、45 d的株防效为89.2%～100.0%，极显著高于噁草酸乳油单剂处理；药后45 d的质量防效分别提高21.1和24.2百分点。可见，噻苯隆悬浮剂和乙烯利水剂分别与噁草酸乳油混配对禾本科杂草具有较好的防除效果，且速效性和持效性较好。     

沿海农区麦田杂草防除技术研究

根据沿海农区麦田杂草发生危害现状 ,麦田杂草可分为禾本科和阔叶类 2大类 ,进行了硬草 (禾本科恶性杂草之一 )、泽漆 (新上升难治阔叶类杂草 )的发生危害规律和有关生物学特性的基础研究 ,重点研究了控制麦田硬草、泽漆的关键措施 ,明确了应用化学除草剂 (骠马、乙草胺、异丙隆、使它隆、苯磺隆及其复配剂 )的核心所在 ,结合其它有关专题研究结果 ,在先进的原则策略指导下 ,组装了沿海农区麦田杂草长效治理技术措施。     

异噁唑草酮·噻酮磺隆在玉米不同种植区应用的除草效果和安全性研究

2016～2017年在东北春玉米种植区和黄淮海夏玉米种植区设立田间试验基地,研究除草剂异噁唑草酮·噻酮磺隆悬浮剂在不同区域玉米田播后苗前处理的杀草谱及除草效果、对玉米安全性及对下茬作物生长的影响。结果表明,26.7%异噁唑草酮·噻酮磺隆悬浮剂141.75～283.5 g ai/hm2在玉米播后苗前使用,对东北春玉米种植区主要杂草稗草、狗尾草、藜、反枝苋、苘麻、刺儿菜和黄淮海玉米种植区主要杂草马唐、牛筋草、反枝苋、马齿苋、铁苋菜等禾本科杂草和阔叶杂草均有理想效果,药后40～45 d,异噁唑草酮·噻酮磺隆上述处理对杂草鲜重防效仍在95%左右,可实现一次施药控制玉米全生长期的杂草,在玉米田具有较好的除草增产作用;对后茬播种的小麦、大豆、花生、油菜、菠菜生长无影响。     

农威豆田防除杂草的安全性试验研究

５％农威ＥＣ是一种低毒、高效、广谱，具有选择性内吸传导型，苗后茎叶处理的豆田除草剂。防除禾本科杂草防效达９５％以上，对阔叶杂草及莎草科杂草防效一般大于８５％，一次性施药，麦茬免耕种植夏大豆，省工省时。按每公顷剂量６７５ｍｌ于傍晚施药，其轻微药害７天后即可恢复，不伤害大豆植株，并增产５－１０％，不污染环境，药效期４０天左右，不影响下茬作物，安全性高，使用方便，在当前农业生产上属少有新品种。     

Efficiency of mesosulfuron-methyl and clodinafop-propargyl dose for the control of Lolium perenne in wheat

Increasing environmental and economic concerns have resulted in considering the potential for the successful use of herbicides at lower doses within an integrated approach to weed management. Therefore, field experiments were carried out to evaluate the efficiency of mesosulfuron-methyl and clodinafop-propargyl dose to control Lolium perenne in pure stand and in mixture with wheat. The herbicides at 5 different doses were assigned in a factorial arrangement (subplots) within planting systems (mainplots). L. perenne biomass was totally different in pure stand and in mixed planting system, irrespective of the herbicide effect. More than 3-fold decrease was caused in the L. perenne biomass by the presence of wheat. Mesosulfuron-methyl was more potent than clodinafop-propargyl in the L. perenne control. Mixed planting enhanced the herbicide performance, increasing the relative potency value of mesosulfuron-methyl. The wheat grain yield received no additional benefit from applying mesosulfuron-methyl at the full recommended dose rather than at half dose. This study demonstrates that L. perenne suppression involving sub-lethal herbicide dose is associated with the wheat competitiveness. Combining competitive cropping systems with reduced herbicide could be an approach to reducing weed populations over time with lower crop production costs.     

Integration of soil-applied herbicides at the reduced rates with physical control for weed management in fennel (Foeniculum vulgare Mill.)

Fennel has been widely used in traditional medicine for their antimicrobial effects. Since fennel is long duration crop and have slow initial growth, it protection from weed is essential. Experiments were conducted for two consecutive seasons to evaluate the efficacy of soil-applied herbicides at the reduced rates in combination with physical control for weed management and optimizing the yield of fennel. Treatments were type of herbicide (trifluralin and pendimethalin), application dose (recommend dose (R), 75% R, 50% R, and 0% R) and physical weed control (none, one hand-weeding at 50 day after planting (DAP), wheat straw mulch). Weed-free control treatment was also included in each year. The results showed that the use of soil-applied herbicides resulted in reduced weed biomass but did not provide season long weed control without an additional physical control. In both seasons, pendimethalin provided better weeds control than trifluralin. Reduced herbicide rates were found to be more effective when herbicides application followed by hand-weeding than when were used alone or combined with mulch. Experimental results also showed that one time increasing in herbicide rates increased seed yield by 17.5 and 7.5% in 2012 and 16.5 and 6.3% in 2013, when one hand-weeding and mulching were used as supplemental control, respectively. Overall, the 75% of the labeled recommended rate of herbicides followed by one hand-weeding at 50 DAP produced consistently high yields and less weed biomass, reflecting both superior weed control and crop safety.     

水稻机插秧“插喷同步”封闭除草技术及配套除草剂防效对比

采用机插秧“插喷同步”技术,于2019年开展大田试验,分别施用4种除草剂（33%嗪吡嘧磺隆、19%氟酮磺草胺、25%双环磺草酮、300 g/L丙草胺+10%苄嘧磺隆）进行除草,对比各除草剂处理对水稻的安全性及对稻田杂草的防治效果。结果表明,药后水稻均未发生可见药害,参试除草剂安全性好;药后35 d供试除草剂对试验田总草防效达95.0%以上;与施用除草剂处理相比,未施药对照水稻产量损失严重,减幅12.5%~42.7%。可见,“插喷同步”技术是一种高效除草技术,供试4种除草剂均能有效防治杂草,降低除草成本,提高种稻效益。     

Weed control in a pigeon pea–wheat cropping system

Pigeon pea (Cajanus cajan (L.) Millsp.) seedlings compete poorly against the rapid growth of warm-season annual weeds. Weed control is required before this heat and drought-tolerant legume can be reliably grown in the U.S. southern Great Plains as a potential source of livestock hay between annual plantings of winter wheat (Triticum aestivum L.). Currently, no herbicides are labeled for use on pigeon pea grown in the U.S. Three years of replicated field experiments were conducted to determine the effects of applications (1× and 2× rates) of herbicides (pre-emergence, sulfentrazone + chlorimuron and metribuzin; post-emergence, imazapic and sethoxydim) on weed suppression, pigeon pea dry matter, and carry-over effects on a winter wheat crop. The most abundant summer weeds were broadleaf, and all herbicide treatments, except sethoxydim (grass herbicide), reduced weed densities compared to untreated plots without adversely affecting pigeon pea stands. Imazapic treatments provided the most effective weed control. Overall average pigeon pea dry matter ranged from 75 to 256 g m⁻² with sethoxydim and the untreated control ≤ metribuzin ≤ sulfentrazone + chlorimuron ≤ hand weeded control ≤ imazapic. Compared to the hand-weeded control, imazapic treatments greatly reduced wheat dry matter (1×, 65% and 2×, 91%) and grain yield (1×, 59% and 2×, 93%). Imazapic should not be used unless nontransgenic imidazolinone herbicide tolerant wheat cultivars are planted. While the other herbicides decreased negative effects of weeds on pigeon pea dry matter without greatly affecting productivity of a following wheat crop, appropriate labels for each of these herbicides will be required prior to their use by southern Great Plains pigeon pea producers.     

Effect of herbicide application on weed flora under conservation agriculture in Zimbabwe

Increased challenges of weed control in the smallholder farming sector of southern Africa have often resulted in small yields. The objective of this study was to evaluate the effects of different weed control strategies on weed flora and composition under conservation agriculture (CA) systems in Zimbabwe. This study was conducted at three on-station trial sites namely Domboshawa Training Centre (DTC), University of Zimbabwe farm (UZ farm) and Henderson Research Station (HRS) in a maize–soybean rotation for four seasons from 2009–2010 to 2012–2013 seasons. Hand weeding was done whenever weeds were 10 cm tall or 10 cm in circumference for weeds with a stoloniferous growth habit. Weed identification was done up to the weed species level, and the Shannon–Weiner diversity and evenness index was used to determine the response of weed flora to herbicides. Results showed that there were more weeds in the early years which decreased gradually until the final season. Weed species diversity was not affected by herbicide application and the results indicated that weed species diversity was small in CA systems. Annual weed species constituted a greater proportion of species, and species richness decreased with the duration of the study. Richardia scabra L. and Galinsoga parviflora Cav. were the most common dominant weed species at all sites and in all seasons. Moreover, herbicide application had no effect on the evenness of weeds in the plots but site characteristics had a significant effect on the distribution of weed species (weed species evenness). The results presented in this study suggest that herbicide application facilitates a depletion of weed seed bank/number of weeds over time. Thus, herbicide application in CA has potential to reduce weed density, species richness and species diversity in the long term which may lead to more labour savings and larger yields.     

Tolerance of winter wheat (Triticum aestivum L.) to pre-emergence and post-emergence application of saflufenacil

Saflufenacil is a new herbicide being developed for pre-plant burndown for non-selective removal of broadleaf weeds and pre-emergence (PRE) broadleaf weed control in field crops, including maize, soybean, sorghum and wheat. As part of studying the potential use pattern of this herbicide, four field studies were conducted in 2006 and 2007 at Concord, northeast Nebraska, to determine winter wheat tolerance to PRE and post-emergence (POST) applications of saflufenacil. The fall POST applications were conducted at the 2–3 leaf stage (5 cm height) whereas the spring POST and tank-mixes studies were sprayed at the 4th node stage (40 cm height) of crop. Dose-response curves based on log-logistic model were used to determine the ED (effective dose) values of saflufenacil for visual ratings of crop injury and relative yield. There was no crop injury or yield reduction with PRE applied saflufenacil dose of up to 400 g a.i. ha⁻¹. However, there was significant crop injury in the POST applications in the fall (up to 95%) and in the spring (up to 67%). There was also yield reduction of as much as 66% in the fall and 58% in the spring POST applications. Addition of adjuvants also increased crop injury levels. For example, at 14 days after treatment in the fall applications, about 5% visual crop injury (ED₅) was evident with 82, 67 and 10 g a.i. ha⁻¹ of saflufenacil compared with 51, 30 and 11 g a.i. ha⁻¹ in the spring, with no adjuvant, or non-ionic surfactant (NIS), or crop oil concentrate (COC), respectively. Saflufenacil at half the proposed used dose of 25 g a.i. ha⁻¹ was safe to mix with the currently used POST herbicides of wheat with no visible crop injury and yield reduction. PRE applications of saflufenacil would be safe for use in winter wheat; however, the POST application of saflufenacil alone or with the adjuvant NIS or COC produces unacceptable injury and yield loss. These results are similar to the proposed PRE use pattern of saflufenacil. In addition, the proposed label does not suggest the POST use of saflufenacil in winter wheat, or any other cereal crops, which is similar to what we have concluded from this study.