Efficacy of Trifluralin Compared to Ethalfluralin Applied Alone and Co-Applied with Halosulfuron for Weed Management in White Bean

There are a limited number of herbicides registered for weed management in white bean production in Ontario, Canada. Five field experiments were completed in Ontario from 2016 to 2018 to compare the efficacy of trifluralin and ethalfluralin applied alone and in combination with halosulfuron, applied preplant incorporated (PPI), for weed control efficacy and white bean tolerance and seed yield. At 2 and 4 WAE, there was no white bean injury from the herbicide treatments evaluated. Trifluralin applied PPI provided up to 32%, 99%, 13%, 99%, 27%, 99% and 99% control of velvetleaf, redroot pigweed, common ragweed, common lambsquarters, wild mustard, barnyardgrass and green foxtail, respectively. Trifluralin and ethalfluralin provide similar control of velvetleaf, redroot pigweed, barnyardgrass and green foxtail control, however, ethalfluralin is slightly more efficacious on common ragweed, common lambsquarters and wild mustard. Halosulfuron (35 g∙ai∙ha−1), applied PPI, provided as much as 76%, 98%, 96%, 96%, 100%, 19% and 23% control of velvetleaf, redroot pigweed, common ragweed, common lambsquarters, wild mustard, barnyardgrass and green foxtail, respectively. Trifluralin (600 or 1155 g∙ai∙ha−1) + halosulfuron (35 g∙ai∙ha−1), applied PPI, provided up to 88%, 100%, 98%, 100%, 100%, 99% and 98% control of velvetleaf, redroot pigweed, common ragweed, common lambsquarters, wild mustard, barnyardgrass and green foxtail, respectively. Ethalfluralin (810 or 1080 ai∙ha−1) + halosulfuron (35 g∙ai∙ha−1) provided similar control. Weed interference decreased white bean seed yield 44% - 45% with trifluralin, 30% - 41% with ethalfluralin and 34% with halosulfuron. However, decreased weed interference with trifluralin and ethalfluralin applied in combination with halosulfuron resulted white bean seed yield that was similar to the weed-free control. Trifluralin or ethalfluralin co-applied with halosulfuron can be safely used in white bean production for the control of common annual grass and broadleaf weeds in Ontario.

Control of Glyphosate-Resistant Marestail in Identity-Preserved or Glyphosate-Resistant and Glyphosate/Dicamba-Resistant Soybean with Preplant Herbicides

Two studies, each consisting of six field experiments were conducted in growers’ fields in 2018 and 2019 to determine the optimal herbicide tankmixes, applied preplant (PP) for the control of glyphosate-resistant (GR) marestail in 1) identity-preserved and glyphosate-resistant soybean (Study 1) and, 2) glyphosate/dicamba-resistant soybean (Study 2). There was no significant injury in soybean with the PP herbicides evaluated in both studies. In Study 1, at 8 weeks after treatment (WAA), glyphosate + saflufenacil, glyphosate + 2,4-D ester, glyphosate + pyraflufen/2,4-D, glyphosate +, 4-D choline or glyphosate + halauxifen-methyl, applied PP, controlled GR marestail 93%, 58%, 60%, 67% and 71%, respectively. The addition of metribuzin to the tankmixes of glyphosate + saflufenacil, 2,4-D ester and pyraflufen/2,4-D increased the control to 98%, 91% and 95%, respectively. The addition of metribuzin + chlorimuron-ethyl to 2,4-D choline/glyphosate and glyphosate + halauxifen-methyl increased the control to 94% and 93%, respectively. In Study 2, at 8 WAA, glyphosate/dicamba, applied PP, controlled GR marestail 89% in glyphosate/dicamba-resistant soybean. The addition of metribuzin or saflufenacil to glyphosate/dicamba controlled GR marestail 86% and 97%, respectively. At 8 WAA, S-metolachlor/dicamba controlled GR marestail 83%. The addition of metribuzin or saflufenacil to the above premix controlled GR marestail 87% and 97%, respectively. Density and biomass reductions were similar to visible control. GR marestail interference reduced soybean yield 60% and 53% in Study 1 and 2, respectively. Reduced GR marestail interference with all the herbicide treatments evaluated in both studies resulted in soybean yield that was similar to the weed-free control.

Glyphosate-Resistant Canada Fleabane Control with Three-Way Herbicide Tankmixes in Soybean

Eight field trials (2 in 2016, 3 in 2017, 3 in 2018) were conducted in farmers’ fields with heavy infestations of GR Conyza canadensis (Canada fleabane, horseweed or marestail) to evaluate glyphosate (900 g ae ha-1) plus saflufenacil (25 g ai ha-1), 2,4-D ester (500 g ai ha-1) or paraquat (1100 g ai ha-1) applied preplant (PP) as 2-way tankmixes, or in 3-way tankmixes with sulfentrazone (140 g ai ha-1), flumioxazin (107 g ai ha-1) or metribuzin (400 g ai ha-1) for the glyphosate-resistant (GR) C. canadensis control in GR soybean. Glyphosate plus saflufenacil applied PP controlled GR C. canadensis as much as 90%. The addition of sulfentrazone, flumioxazin or metribuzin to the tankmix provided as much as 93%, 96% and 97% control of GR C. canadensis, respectively. Glyphosate plus 2,4-D ester applied PP provided as much as 59% control of GR C. canadensis. The addition of sulfentrazone, flumioxazin or metribuzin to the tankmix provided as much as 60%, 59% and 91% control of GR C. canadensis, respectively. Glyphosate plus paraquat applied PP provided as much as 85% control of GR C. canadensis. The addition of sulfentrazone, flumioxazin or metribuzin to the tankmix provided as much as 88%, 89% and 98% control of GR C. canadensis, respectively. Density and biomass reductions of GR C. canadensis with herbicides evaluated followed the same pattern as weed control evaluations. GR C. canadensis interference reduced soybean yield 66%. Reduced GR C. canadensis interference with the preplant herbicides evaluated provided soybean yield similar to the weed-free control. Results from this study show that glyphosate plus saflufenacil, glyphosate plus 2,4-D ester or glyphosate plus paraquat tankmixed with metribuzin can provide effective control of GR C. canadensis in GR soybean.

磺酰脲类除草剂对禾谷类作物的安全性及药害研究

采用田间小区试验方法,测定了4种磺酰脲类除草剂对玉米、小麦、谷子、高粱4种禾本科作物的安全性。结果表明,4%玉农乐悬浮剂苗后茎叶处理,有效成份推荐量40g/hm2对玉米安全,2倍量80g/hm2对玉米有轻微药害,3倍量120g/hm2对玉米药害严重,植株矮化穗小。推荐量对小麦、谷子、高粱药害严重,苗期死亡;75%宝收干悬浮剂播后苗前土壤处理,有效成分推荐量25g/hm2、2倍量50g/hm2和3倍量75g/hm2对4种作物均安全。苗后茎叶处理,3个剂量对小麦均无明显药害。推荐量对玉米安全,高粱有轻度药害,谷子药害严重,苗期死亡。2倍量玉米有轻度药害,高粱药害严重,部分苗期死亡。3倍量玉米和高粱药害严重,玉米不能恢复正常生长,高粱大部分苗期枯死;25%宝成干悬浮剂苗后茎叶处理,有效成分推荐量18.75g/hm2推荐量对玉米安全,2倍量37.5g/hm2对玉米有轻微药害,7d左右恢复正常生长。推荐量对小麦、谷子、高粱均有药害,2倍量药害严重,苗期死亡;20%豆磺隆可溶性粉剂播后苗前土壤处理,有效成份推荐量15g/hm2下对4种作物均安全,2倍量30g/hm2和3倍量45g/hm2下对玉米、小麦、谷子安全,高粱有轻度药害。苗后茎叶处理,推荐量、2倍量和3倍量对小麦均安全。推荐量对谷子安全,2倍量和3倍量谷子有轻度药害。推荐量下玉米、高粱均有药害,2倍量和3倍量药害严重,不能恢复正常生长。

我国东北地区常见除草剂药害原因分析与解决方法

我国除草剂药害发生频繁,损失严重,主要原因是除草剂使用技术落后,喷雾器械不标准及使用技术不规范。应加强农药管理,注重除草剂安全性评价,对不安全的除草剂及长残留除草剂如有替代品种取消注册登记,对无替代品种限制使用;制定喷雾器械质量标准及使用技术规范;首先系统地培训技术队伍,普及规范的化学除草技术,利用内源植物生长调节剂缓解药害。

关于除草剂田间药效试验安全性评价方法问题的探讨

在除草剂田间药效试验中,安全性评价方法十分重要。除草剂安全性评价必须全面和准确,要有倍量试验,要特别注意在不良环境条件下的试验。苗前除草剂要进行不同土壤有机质、质地、pH值等试验,还要进行低温高湿、拱土期施药、混土施药等试验。苗后除草剂要进行的试验包括以下各项:高温低湿、低温高湿(最好有两天低于10℃的气温试验)、喷液量试验,作物不同生育阶段和品种试验,加不同类型的喷雾助剂及剂量试验;要特别重视长残效除草剂对后茬敏感作物安全性的评价试验。改进施药技术可避免或减轻药害。

除草剂对作物产生药害的原因及治理对策

本文论述了我国除草剂使用过程中作物产生药害的主要原因和除草剂药害的治理对策。提出:除草剂使用不合理,除草剂和作物本身的因素,异常的环境条件是药害产生的主要原因。杜绝假冒伪劣及不合格产品,加强除草剂试验、示范、推广工作,深化除草剂应用技术研究,加强农民用药技术水平培训是除草剂安全使用应解决的问题。

长残留性除草剂与黑龙江省农业的未来发展

文章从种植业结构角度,分析了黑龙江省连年大量使用长残留性除草剂的原因及其弊端。评价了主要长残留性除草剂氯嘧磺隆、氯磺隆、莠去津、咪草烟、异草酮、氟磺胺草醚对后茬作物的安全间隔期。阐述了减轻长残留性除草剂对后茬作物残留药害的观点。

南方二氯喹啉酸残留药害早期诊断和预警亟待研究

除草剂残留药害严重威胁南方稻-菜高效轮作生产模式,其早期诊断和预警成为亟待解决的难题。二氯喹啉酸(3,7-二氯-8-喹啉羧酸)是华南稻田最常用的除草剂之一,其残留药害具有很高的潜伏性,轻则使农产品品质下降和减产,重则导致绝收。常规形态学诊断的方法无法对二氯喹啉酸土壤残留药害有效进行早期诊断和预警,且容易误诊;而通过土壤含量检测进行药害诊断,操作复杂,成本高而难以推广。因而,在明确植物对二氯喹啉酸敏感性的机制和相关检测指标的基础上,建立二氯喹啉酸残留药害量化分级指标系统,并定量研究各药害等级所对应的作物生产损失风险评估技术亟待研究解决。

内蒙除草剂使用及药害情况解析

本文概述了我国内蒙古自治区近年来除草剂使用和药害发生的基本现状,探讨并分析了除草剂药害发生的主要原因,并提出了规避药害的一些建议等。加强农民技术培训与科学技术指导,规范、合理的使用除草剂,将有效的避免农作物药害,有利于保证我国农产品质量安全。

浅析除草剂药害发生原因与防控措施

分析了部分除草剂易产生药害的原因,并对如何防控除草剂药害和受药害后的补救措施进行了分析与讨论。

我国除草剂造成作物的药害与预防

我国除草剂大量应用已近50年,其中一个重要问题是经常发生作物药害,从而成为制定杂草治理措施的关键所在。根据农业实践,论述了作物药害的原因及其预防措施,如正确的除草剂使用方法、限制与禁用长残留性除草剂、使用增效剂以及作物轮作、适宜的耕作与栽培措施等。

主要农作物除草剂药害比较及预防对策

造成主要农作物药害的除草剂品种有磺酰脲类、二苯醚类、苯氧羧酸类的部分品种,以及百草枯、草甘膦、乙草胺等,但以磺酰脲类除草剂造成的药害较为常见。笔者探讨了药害的表现及其补救、预防措施。

北部高寒区大豆化学除草药害产生原因分析

北部高寒区常用除草剂产生药害的原因,一是受天气环境、土壤有机质、土壤残留、飘移、沾染等自然环境的影响;二是使用技术即人为的作业不标准、施用时期、混配技术、浓度过量、误导与误用;三是除草剂本身成份决定的如选择性不强、质量问题。

除草剂残留对亚麻的影响及预防措施

长残效除草剂大面积施用及超量施用,对后茬作物亚麻造成严重危害,已成为影响我国北方亚麻主产区产业发展的重要因素。本文阐述了亚麻受药害原因及症状表现,列举了对后茬亚麻有影响的除草剂种类并提出了预防措施。

Characterizing downwind drift deposition of aerially applied glyphosate using RbCl as tracer

Rubidium chloride(RbCl)was used as a tracer tank-mixed with active ingredients to profile downwind deposition of aerially applied crop protection and production materials to characterize off-target drift,which helps improve spray efficiency and reduce environmental contamination.Mylar sheets were placed on a holder in the field at each sampling station to collect sprayed solution.RbCl tracer was used to assess downwind drift of nozzles mounted on the booms installed and controlled on both sides of an agricultural airplane.The experiment was conducted on a field covered by Bermuda grass(Cynodon dactylon).During the experiment,the airplane was planned to fly three passes with three replications at each of three different altitudes,3.7 m,4.9 m,and 6.1 m for total of 27 flight runs.The results indicated that sampling station location had a significant effect on RbCl concentration.However,application release altitude was not significant to the change of RbCl.Another practical application in the same aerial application system was used to assess crop injury from the off-target drift of aerially applied glyphosate.RbCl concentrations measured from Mylar sheets were correlated with visual injury,plant height,shoot dry weight,leaf chlorophyll content,and shikimate,which were measured from the leaves and plant samples collected.Overall,RbCl is an effective tracer for monitoring spray applications from agricultural aircraft and unmanned aerial vehicles to intensify agriculture output and minimize environmental impact.

Ground-based hyperspectral remote sensing for weed management in crop production

Agricultural remote sensing has been developed and applied in monitoring soil,crop growth,weed infestation,insects,diseases and water status in farm fields to provide data and information to guide agricultural management practices.Precision agriculture has been implemented through prescription mapping of crop fields at different scales with the data remotely sensed from space-borne,airborne and ground-based platforms.Ground-based remote sensing techniques offer portability,flexibility and controllability in applications for precision agriculture.In weed management,crop injury from off-target herbicide spray drift and herbicide resistance in weeds are two important issues.For precision weed management,ground-based hyperspectral remote sensing techniques were developed for detection of crop injury from dicamba and differentiation between glyphosate resistant and sensitive weeds.This research presents the techniques for ground-based hyperspectral remote sensing for these two applications.Results illustrate the advantages of ground-based hyperspectral remote sensing for precision weed management.