Occurrence of Glyphosate-Resistant Horseweed (Conyza canadensis) Population in China

Horseweed （Conyza canadensis）, an invasive alien weed, is one of the main weeds in orchards in China. Although glyphosate has been used for control of horseweed and many other weeds in orchards for more than 25 years in China, a case of glyphosate-resistant horseweed has not been identified in orchard in China so far despite glyphosate-resistant horseweed cases have been reported in some other countries. Seeds of 25 horseweed populations were collected from different orchards with different glyphosate application history. Potted seedlings with 11-13-leaf growth stage were treated with glyphosate at 0.035, 0.07, 0.14, 0.28, 0.56, 1.12, 2.24, 4.48, and 8.96 kg a.i. ha-1. The dosage dependence response curve of each population was constructed with Log-logistic dose response regression equations. The ED50 value of each population was calculated and compared with the susceptible population from China. Different populations had different relative glyphosate-resistant levels which increased with the number of years of glyphosate application. Two populations with the highest resistance levels, 8.28 and 7.95 times, were found in Ningbo, Zhejiang Province, China, where glyphosate was used for weed control in orchards twice each year for 15 yr. The two resistant populations accumulated approximately two to four times less shikimic acid than the two susceptible populations 48 h after glyphosate application.

A new derivative of triterpene with anti-melanoma B16 activity from Conyza canadensis

A new derivative of triterpene named Erigeronol 1 was isolated from the EtOH extract of the aerial part of Conyza canadensis together with 15 known compounds for the first time from this plant.The structure of Erigeronol 1 was elucidated as 3-O-（hydroxyacetyl） -23,28-dihydroxy-β-amyrin by hydrolysis and spectroscopic analysis.Erigeronol 1 showed potent cytotoxic activity with IC_（50） value of 7.77±0.47μg/mL against melanoma B16 determined by the 3-（4,5-dimethylthiazo-2-yl）-2,5-diphenyltetrazolium bromide（MTT） method.

Morpho-Physiological Characterization of Glyphosate-Resistant and -Susceptible Horseweed (Conyza canadensis) Biotypes of US Midsouth

Horseweed is traditionally considered a non-cropland weed. However, populations resistant to glyphosate have eventually become established in no-till agronomic cropping systems. Growth chamber and greenhouse experiments were conducted to compare selected biological and physiological parameters of glyphosate-resistant (GR) and -susceptible (GS) horseweed biotypes from Mississippi with a broader goal of fitness characterization in these biotypes. Vegetative growth parameters (number of leaves, rosette diameter and area, shoot and root fresh weights) were recorded weekly from 5 to 11 wk after emergence and reproductive attributes [days to bolting (production of a flowering stalk) and flowering] and senescence were measured for both GR and GS biotypes under high (24°C/20°C) and low (18°C/12°C) temperature regimes, both with a 13-h light period. Physiological traits such as net photosynthesis, phenolic content, and cell membrane thermostability, all in the presence and absence of glyphosate, and leaf content of divalent cations such as Ca2+ and Mg2+ were assayed in the two biotypes under the high temperature regime. All horseweed vegetative growth parameters except root fresh weight were higher in the high temperature regime compared to that in low temperature regime in both biotypes. Number of leaves, rosette diameter and area, shoot and root fresh weight were 40 vs. 35, 9.3 vs. 8.7 cm, 51 vs. 43 cm2, 3.7 vs. 3.2 g, and 3.5 vs. 4.2 g under high and low temperature conditions, respectively, when averaged across biotypes and weekly measurements. All growth parameters listed above were higher for the GR biotype compared to the GS biotype. Number of leaves, rosette diameter and area, shoot and root fresh weight were 38 vs. 37, 9.1 vs. 8.9 cm, 50.2 vs. 44 cm2, 3.9 vs. 3.1 g, and 4.3 vs. 3.5 g for GR and GS biotypes, respectively, averaged across the temperature treatments and weekly measurements. Reproductive developmental data of these biotypes indicated that the GS biotype bolted earlier than the GR biotype. The GS biotype had more phenolic content and exhibited higher cell membrane thermostability, but less net photosynthetic rate compared to the GR biotype. At 48 h after treatment with glyphosate, there was no change in phenolic content of both GR and GS biotypes. However, glyphosate reduced cell membrane thermostability and net photosynthetic rate more in the GS biotype than that in the GR biotype. Chemical analysis of GR and GS leaf tissue did not reveal any differences in levels of divalent cations such as Ca2+ and Mg2+. Further studies are needed to determine if some of the differences between the two biotypes observed above relate to fitness variation in a natural environment.

Early Growth and Development of Horseweed (<i>Conyza canadensis</i>(L.) Cronq.)

Horseweed (Conyza canadensis (L.) Cronq.) produces thousands of small elongated seeds which are botanically defined as achenes;yet, relative to the quantity of achenes produced, few seedlings survive to produce mature plants. The developmental progression from achene to 4 mm seedlings was documented, and seedling response to moisture deprivation was described. Radical protrusion through the pericarp occurred between 18 and 30 hours after onset of imbibition in water or when germinated on soil at or greater than field capacity. A ring of root hair initials formed immediately after radical emergence at the interface of what was to become the separation between the root and hypocotyl. By 48 hours post imbibition, radicals differentiated into a distinct root with root cap and a hypocotyl, and root hairs elongated. By 72 hours post imbibition, seedlings had emerged from the pericarp, and had: expanded photosynthetic cotyledons, a clearly defined hypocotyl, a ring of elongated root hairs exceeding 1 mm in length, and a root equal or longer than the hypocotyl. The epicotyl had not yet emerged, and the total seedling length was approximately 3 to 4 mm. Germination was delayed on soil at or below field capacity. More than 95% of two- and four-day-old seedlings that had been desiccated for more than 24 hours died after being rehydrated.

入侵植物加拿大飞蓬(Erigeron canadensis L.)生理生态适应初探

利用PEG-6000模拟根际干旱胁迫法,研究了入侵植物加拿大飞蓬(Erigeron canadensis L.)在水分胁迫下的生理生态变化.在干旱胁迫下,加拿大飞蓬体内的丙二醛(MDA)、脯氨酸(Pro)含量、过氧化物酶(POD)酶活、超氧化物酶(SOD)酶活以及可溶性蛋白含量均发生了不同程度的变化.在不同胁迫强度下,MDA含量、Pro含量、可溶性蛋白含量和POD酶活均呈现上升趋势;在胁迫初期,加拿大飞蓬体内SOD酶活呈现上升趋势,胁迫中期出现下降趋势,后期又呈现出明显的上升趋势,表明其体内抗旱机制多种多样,能够适应多种生境.

加拿大一枝黄花(SolidagocanadensisL.)不同水浸液对作物种子发芽和生长的影响

分别采用2种方法获取加拿大一枝黄花的根茎和叶水浸液,对小麦、大麦、玉米、水稻、番茄和油菜等6种作物的种子进行发芽率测定,并对小麦、玉米和水稻3种作物幼苗进行生长量试验。结果表明:各水浸液对6种作物的种子萌发均有明显的抑制作用,水稻、小麦和玉米3种作物的幼苗生长受到影响,处理间差异显著。根茎和叶粉碎液的不同浓度对玉米的生长影响不同,浓度越高影响越大,各浓度处理间的差异显著。

外来植物加拿大一枝黄花(Solidago canadensis)入侵的结构基础

采用野外观察、光镜、扫描电镜等手段,对入侵皖北的加拿大一枝黄花形态解剖结构进行了研究,并藉此理解该物种入侵适应的结构基础。结果表明:叶的上、下表皮的气孔数目均较少,具有厚的角质层和长的表皮毛,能起到保水和保护作用;叶片内有发达维管束和束鞘延伸,增加了叶片对光合产物的输导能力,以满足地下营养器官发育的需要。茎具有较强输导和支持能力的结构特征。主根过早停止发育,以适应地下逸生结构发育的需要。加拿大一枝黄花花期、花序结构和未能与本地昆虫建立固定访问关系使部分头状花序不育,成熟花粉粒外有胼胝质包被,有利于花粉传播,其花粉粒属于较为进化的类型;根状茎含较多菊糖,具备成为独立散布体的物质和结构基础。

加拿大一枝黄花(Solidago canadensis L.)水浸提液对小麦的化感作用及机制

为了阐明加拿大一枝黄花(Solidago canadensis L.)对小麦的化感作用机制,研究了加拿大一枝黄花新鲜茎叶的水浸提液对小麦(Triticum aestivum)种子萌发和幼苗生长的影响,以及对小麦种子中α-淀粉酶活性、叶片中脂质过氧化作用及根系活力的影响。整个试验在完全随机情况下进行,一组质量浓度0.025、0.05和0.1 g·mL-1水浸提液用于对小麦化感作用的研究,在此基础上,设置另一组质量浓度0.01、0.02和0.03 g·mL-1水浸提液用于作用机制随水浸提液处理7和14 d时的变化研究,均用蒸馏水作空白对照。结果表明:在水浸提液质量浓度为0.025、0.05和0.10 g·mL-1时,加拿大一枝黄花水浸提液对小麦种子萌发和幼苗生长表现出很强的抑制作用,而且抑制强度随水浸提液质量浓度的增加而增强。水浸提液抑制小麦种子α-淀粉酶的活性,0.03 g·mL-1时达到显著水平(P<0.05)。水浸提液处理小麦7 d后,小麦叶片中SOD、POD和CAT活性均受到抑制,MDA含量显著升高,作用强度随水浸提液质量浓度的增加而增强。处理14 d后,SOD与CAT活性呈现出不规律性波动,MDA含量仍呈上升趋势,总体水平低于7 d时的试验结果;POD活性呈下降趋势,但与对照无显著差异,总体水平高于7 d时的试验结果。水浸提液处理后,小麦根系活力升高,随着处理时间延长,根系活力有所下降。结论:加拿大一枝黄花水浸提液对小麦种子萌发的抑制作用与α-淀粉酶活性的变化有关,对小麦幼苗生长的抑制作用与脂质过氧化作用和根系活力的变化有关。

Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.)

It is less known whether and how soil metal lead （Pb） impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species （Solidago canadensis L.） in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal （AM） fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels （control, 300, and 600 mg/kg soil） were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species （ Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum）. The ^15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization （root length colonized, RLC%） but did not affect spore numbers, N （including total N and ^15N） and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant （root and rhizome）. The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

Characteristics of soil microbial community functional and structure diversity with coverage of Solidago Canadensis L

The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.

Chemical Constituents from Mentha haplocalyx Briq.(Mentha canadensis L.)and Theirα‑Glucosidase Inhibitory Activities

Mentha haplocalyx(Mentha canadensis)is widely used as a medicinal plant in traditional Chinese medicine,and the extracts of its aerial parts are found to signifcantly inhibit the activity ofα-glucosidase with an IC_(50) value of 21.0μg/mL.Bioactivity-guided isolation of the extracts aforded two new compounds(1 and 2),together with 23 known ones(3-25).Their structures were established by extensive spectroscopic analyses(1D and 2D NMR,MS,IR and UV).Compounds 1-17 and 21-25 were evaluated for theirα-glucosidase inhibitory activities.Compound 11 was the most active ones with an IC_(50) values of 83.4μM.These results verify theα-glucosidase inhibitory activity of M.haplocalyx(M.canadensis)and specify its active compounds for the frst time.

水淹胁迫对小蓬草(Conyza canadensis)的形态结构与生理生化特性的影响

为研究水淹胁迫对三峡库区消落带重要物种小蓬草(Conyza canadensis)的生理生化特性及解剖结构的影响,以消落带区小蓬草为试验材料,设置全淹组(SG)和半淹组(Ss G)处理,测定与小蓬草在淹水过程中随着时间增长的生理指标与根系解剖变化。结果表明:水淹30 d,淹水组小蓬草相对叶面积和平均茎高与对照相比都显著降低,而根系主根长和侧根数量都显著高于对照组。SsG丙二醛(MDA)、脯氨酸、超氧化物歧化酶(SOD)活性及根系活力都升高,与对照组达到了显著差异,SG组的以上指标及可溶性还原糖都与对照组达到了显著差异,并且叶绿素、MDA和根系活力与SsG之间也达到了显著差异,解剖结构中,两种淹水处理的根系周皮细胞的气腔面积增加,木质部出现溶生型气腔;水淹50 d,SsG叶片边缘坏死,心部小叶存活,SG地上部分基本腐烂,两种淹水处理根系韧皮部出现坏死,木质部残存,解剖结构表明此时根系外围组织瓦解,生理指标测定表明,与对照相比,Ss G的叶绿素极显著降低,可溶性糖、MDA、脯氨酸及SOD都显著增加,SsG和SG根系活力较对照都显著降低。小蓬草在淹水过程中根系的存活时间超过叶片,根系在通气组织结构上启动响应机制,表明小蓬草在水淹胁迫中主要通过减少地上部分的生长量,增加地下根系的生长与结构的调节来适应水淹具有短期耐淹能力,这为库区消落带入侵物种的适应性及生态植被恢复提供参考数据。

Application and Characterization of Cellulose Acetate Membrane Produced from Herbaceous Plant: Solidago Canadensis L.

In this work,the viability of Solidago Canadensis L. for cellulose acetate membrane production was tested. The cellulose was extracted from Solidago Canadensis L. stem by organic solvents,and the cellulose diacetate was obtained by acetylization of cellulose. The properties of the intermediate products of cellulose pulp and cellulose diacetate were characterized by FT-IR and XRD. Compared with commercial cellulose diacetate,the properties of cellulose diacetate were similar to those of the commercial cellulose diacetate. The cellulose acetate membrane with desirable pure water flux and rejection rate was obtained from cellulose diacetate by solution casting. The membrane showed favorable hydrophilic property so that it had good anti-pollution performance. The maximum pure water flux of the membrane was 27. 21 m L /( cm2· h) and the maximum rejection rate was 80. 39%. The results demonstrated that the membrane obtained from herbaceous plant: Solidago Canadensis L. had good performance of ultrafiltration.

Effects of Water Extract of Erigeron canadensis L. on Seed Germination of Plants

[Objective] The paper was to explore the effect of water extract of Erigeron canadensis L. on seed germination of plants. [Method] Using constant temperature culture method, the effects of water extracts of roots, stems and leaves of E. canadensis on seed germination of 14 species of test plants （crops and weeds） were studied. [Result] Water extracts of roots, stems and leaves of E. canadensis had obvious inhibition effect on seed germination of test plants. The water extract of leaves had the strongest inhibition effect, which could completely inhibit the seed germination of Crepis tectorum L., Amaranthus tricolor L. and Chrysanthemum coronarium L. under the lower concentrations of 0.050 and 0.075 g/ml, and completely inhibit seed germination of all the plants under the concentration of 0.400 g/ml except Zea maize L. and Allium fistulosum L.; followed by water extract of stems, and the water extract of roots had the lowest the inhibition effect, except for completely restraining seed germination of Lycopersicum esculentum L. under the concentration of 0.300 g/ml, it still could not completely restrain seed germination of the other plants under the highest concentration of 0.500 g/ml. The inhibition effect of water extract of E. canadensis on seed germination of plants had obvious selectivity, which had more obvious effect on dicotyledonous plants than monocotyledonous plants. [Conclusion] The study provided reference for screening and utilization of allelochemicals of E. canadensis and research on its allelopathy mechanism.

Joint toxic effects of heavy metals and atrazine on invasive plant species Solidago Canadensis L.

In this study, the joint effects of Cd(Ⅱ), Pb(Ⅱ) and atrazine (ATR) on Solidago Canadensis L. were investigated. The results showed that soil containing Cd, Pb and ATR could inhibit root elongation of Solidago Canadensis L., and that there was a positive linear relationship between the inhibitory rate of root elongation and the concentrations of Pb(Ⅱ). The mixture of Cd(Ⅱ) and Pb(Ⅱ)-ATR in soil showed a significant adverse effect on root and shoot biomass of Solidago Canadensis L. Acetylsalicylic acid (ASA) contents increased slightly at the lower concentrations of Cd(Ⅱ)-ATR, then decreased when Cd(Ⅱ)-ATR concentrations were higher than those of 1.0 TUmix(Cd+ATR). The toxic effect of Pb(Ⅱ)-ATR on the ASA contents of Solidago Canadensis L. was greater than that of Cd(Ⅱ)-ATR. Soluble sugar contents firstly decreased and then increased with increasing concentrations of Cd(Ⅱ)-ATR and displayed fluctuation with increasing concentrations of Pb(Ⅱ)-ATR. Total protein contents in-creased with increasing concentrations of Cd(Ⅱ) and Pb(Ⅱ)-ATR , relative to the control sample. The NP-SH con-tents showed a significant increase up to 12.2 mg/gfw of Cd(Ⅱ)-ATR, followed by a significant decline to 4.5 mg/gfw after 14 days of exposure. The effect of Pb(Ⅱ)-ATR was similar to that of Cd(Ⅱ)-ATR but the amount of NP-SH was not higher than that of Cd(Ⅱ)-ATR.

Development of Granule Composition Based on the Total Evaporated Extract of Bidens Tripartita, Solidago Canadensis and Agrimonia Eupatoria Herbs

The aim of the study is the development and standardization of granules in hard gelatin capsules based on the composition of dry extracts of Bidens tripartita L.,Solidago canadensis L.and Agrimonia eupatoria L.Herbs,possessing nephroprotective activity and antifibrotics in toxic nephropathies.Developed the structure and defined the quality indicators of the pellets with dry extracts of Bidens tripartita L.,Solidago canadensis L.and Agrimonia eupatoria L.herbs.The quality specification for the drug-granules of the composition of dry extracts in solid gelatin capsules is developed.

加拿大一枝黄花白绢病(Sclerotium rolfsii)菌株SC64的生物学特性研究

在实验室条件下初步研究了加拿大一枝黄花白绢病菌株SC64的形态特征、致病性和生物学特性。结果表明:引起加拿大一枝黄花白绢病的病原物是罗氏白绢小菌核菌(Sclerotium rolfsii Sacc.);病菌最适生长培养基为Richard固体培养基和PDA,菌丝生长温度为15～40℃,最适30℃;在偏酸性条件下生长较好,生长适宜pH值为4.0～6.0,最适为5.0;在所测试的碳源中,对蔗糖的利用最好,对乳糖和半乳糖利用最差;氮源测试结果显示对蛋白胨和硝酸钾利用最好,对尿素的利用最差。菌核萌发温度为15～40℃,最适为30℃;菌核在含水量≥50%的麸皮基质上萌发较好;适宜萌发的pH值范围为3.0～9.0。菌丝的致死温度为45℃10 min,菌核的抑制萌发温度为50℃10 min。

加拿大披碱草与披碱草、圆柱披碱草2个种间杂种F_1及其亲本的AFLP分析

以加拿大披碱草（Elymus canadensis L.）与披碱草（E.dahuricus Turcz.）、圆柱披碱草（E.cylindricus（Franch.）Honda）2个种间杂种F1及其亲本为试材,利用AFLP分子标记技术,对2个杂种F1及其亲本的遗传差异性进行比较分析,以期为杂种鉴定及后代选育提供分子依据。结果表明：用筛选出的13个适宜引物共扩增出1247个AFLP位点,其中多态性位点1042个,多态性位点比率高达83.56%;各供试材料的遗传距离（GD）变动在0.4276～0.7486之间,以GD值0.65为基准,5个材料聚为2类,第1类为加拿大披碱草、圆柱披碱草和加拿大披碱草×圆柱披碱草杂种F1,第2类为披碱草、加拿大披碱草×披碱草杂种F1。

小飞蓬捕光叶绿素结合蛋白基因CcLhca-J9克隆及表达分析

【背景】恶性杂草小飞蓬(Conyza canadensis)危害严重,有效治理手段匮乏。植物源羊脂酸可高效抑制小飞蓬光合作用,是一种具有开发潜力的灭生型植物源除草化合物。捕光叶绿素a/b结合蛋白(LHC)是光合系统I(PSI)中重要复合体蛋白,在植物进行光合作用中发挥关键作用。【目的】挖掘羊脂酸抑制小飞蓬的潜在靶标基因,为植物源羊脂酸除草剂的开发提供理论依据。【方法】采用同源克隆和RACE技术从小飞蓬叶片中克隆CcLhca-J9的全长序列,并利用DNAMAN分析其核酸序列特征。在NCBI中搜索LHC的高相似度氨基酸序列,采用邻接法构建系统进化树。利用SWISS-MODEL和ExPaSy在线预测分子量、等电点和蛋白结构。以同源建模结果作为模型,采用AutoDock 4.2软件分析羊脂酸与CcLhca-J9蛋白之间的亲和力。采用实时荧光定量PCR(RT-qPCR)分析羊脂酸和对照药剂阿魏酸及清水处理小飞蓬叶片后CcLhca-J9表达差异。【结果】成功获得小飞蓬CcLhca-J9,基因编码区全长为744 bp,编码247个氨基酸,分子量为26.766 kD,理论等电点为6.43,属于Chloroa_b-bind家族蛋白。系统进化分析表明,CcLhca-J9与除虫菊(GEW73959.1,Tanacetum cinerariifolium)和黄花蒿(PWA35049.1,Artemisia annua)Lhca蛋白进化程度最为接近,同处于菊科这一分支,一致性超过85%,表明该基因家族保守性较强。CcLhca-J9蛋白二级结构具有螺旋、β转角、延伸链、无规则卷曲;以4y28.1.O(2.80Å)为模板进行同源建模,三级结构是单分子物体,具有6个叶绿体a配体,是一个典型的捕光复合物I叶绿素a/b结合蛋白。分子对接显示,羊脂酸与CcLhca-J9蛋白的氨基酸残基Gly68、Phe67、Phe69和Arg197在结合过程中产生了氢键和p-π的作用力。RT-qPCR结果显示,羊脂酸胁迫处理小飞蓬叶片条件下,CcLhca-J9的表达量存在明显差异,药后0—8 h内随时间延长表达量表现出下降的趋势。与对照阿魏酸和清水处理相比,羊脂酸处理抑制了CcLhca-J9的表达。【结论】CcLhca-J9具有典型的捕光叶绿素a/b结合蛋白功能,可能参与了羊脂酸抑制小飞蓬叶片生长过程,是具有开发除草剂潜力的抑草靶标。

Influence of Adjuvants on the Control of Glyphosate-Resistant Canada Fleabane and Waterhemp in Corn with Tolpyralate

Tolpyralate is a new benzoylpyrazole herbicide for weed management in corn. It is recommended to be co-applied with atrazine along with the adjuvants methylated seed oil concentrate (MSO) plus an ammonium nitrogen fertilizer, such as urea ammonium nitrate (UAN). Two studies were conducted on glyphosate-resistant (GR) Canada fleabane and GR waterhemp to determine if an additional adjuvant is still required when tolpyralate plus atrazine are tankmixed with a commercial glyphosate formulation (Roundup WeatherMAX&reg;) in corn. Trials were conducted over a two-year period (2018-19) on farms in south western Ontario with confirmed GR populations. When co-applied with Roundup WeatherMAX&reg;, the addition of MSO to tolpyralate + atrazine increased control of GR waterhemp 9%;however, there was no increase in GR Canada fleabane control from the addition of additional adjuvants. At 8 WAA, all treatments provided > 91% and > 84% control of GR waterhemp and GR Canada fleabane, respectively. This study concludes that the addition of Roundup WeatherMAX&reg;to tolpyralate plus atrazine improves the control of GR waterhemp and GR Canada fleabane in corn.