Evaluation of Florpyrauxifen-benzyl on Herbicide-Resistant and Herbicide-Susceptible Barnyardgrass Accessions

2017 ◽  
Vol 32 (2) ◽  
pp. 126-134 ◽  
Author(s):  
M. Ryan Miller ◽  
Jason K. Norsworthy ◽  
Robert C. Scott

AbstractFlorpyrauxifen-benzyl is a new herbicide under development in rice that will provide an alternative mode of action to control barnyardgrass. Multiple greenhouse experiments evaluated florpyrauxifen-benzyl efficacy on barnyardgrass accessions collected in rice fields across Arkansas, and to evaluate its efficacy on herbicide-resistant biotypes. In one experiment, florpyrauxifen-benzyl was applied at the labeled rate of 30 g ai ha−1to 152 barnyardgrass accessions collected from 21 Arkansas counties. Florpyrauxifen-benzyl at 30 g ai ha−1effectively controlled barnyardgrass and subsequently reduced plant height and aboveground biomass. In a dose-response experiment, susceptible-, acetolactate synthase (ALS)-, propanil-, and quinclorac-resistant barnyardgrass biotypes were subjected to nine rates of florpyrauxifen-benzyl ranging from 0 to 120 g ai ha−1. The effective dose required to provide 90% control, plant height reduction, and biomass reduction of the susceptible and resistant biotypes fell below the anticipated labeled rate of 30 g ai ha−1. Based on these results, quinclorac-resistant barnyardgrass as well as other resistant biotypes can be controlled with florpyrauxifen-benzyl at 30 g ai ha−1. Overall, results from these studies indicate that florpyrauxifen-benzyl can be an effective tool for controlling susceptible and currently existing herbicide-resistant barnyardgrass biotypes in rice. Additionally, the unique auxin chemistry of florpyrauxifen-benzyl will introduce an alternative mechanism of action in rice weed control thus acting as an herbicide-resistance management tool.

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1057 ◽  
Author(s):  
Rafael R. Mendes ◽  
Hudson K. Takano ◽  
Rubem S. Oliveira ◽  
Fernando S. Adegas ◽  
Todd A. Gaines ◽  
...  

Wild poinsettia (Euphorbia heterophylla L.) is an important weed species in southern Brazil, especially due to the evolution of multiple herbicide resistance (e.g., acetolactate synthase (ALS)- inhibitors, protoporphyrinogen oxidase inhibitors, and glyphosate). The mechanism of resistance to imazamox was investigated in two wild poinsettia populations (R1 and R2) from southern Brazil and compared to a known susceptible (S) population. Imazamox dose-response experiments revealed high levels of resistance: 45-fold and 224.5-fold based on dry biomass reduction, for R1 and R2, respectively. Extremely high concentrations of imazamox (20,000 µM) were not sufficient to provide 50% inhibition of ALS enzyme activity (I50) for R1 or R2. Hence, resistance levels were estimated to be greater than 123-fold for both populations based on in vitro ALS assays. The ALS gene from all R1 and R2 plants had a Trp574Leu mutation. A genotyping assay was developed to discriminate resistant and susceptible alleles based on the Trp574Leu mutation.


Author(s):  
Ricardo Alcántara-de la Cruz ◽  
Guilherme Moraes de Oliveira ◽  
Leonardo Bianco de Carvalho ◽  
Maria Fátima das Graças Fernandes da Silva

Brazil is a large producer and exporter of crops in global terms. Weeds may be responsible for ~14% of crop losses, depending on the crop system. Herbicides occupy 58% of the Brazilian pesticide market; however, the continuous use of these products and the high selection pressure have led to the emergence of weeds resistant to herbicides. Today, there are 51 weed species reported as being resistant to herbicides in Brazil, of which 17 involves cross and multiple-resistance. Acetolactate synthase (ALS), acetyl coenzyme A carboxylase (ACCase) and 5-enolpiruvylshikimate-3-phosphate synthase (EPSPs) inhibitors are the herbicidal groups with the most resistance cases. Soybean, corn, rice, wheat and cotton present 30, 12, 10, 9 and 8 cases, respectively, occurring mainly in herbicide-resistant crop fields from the Southern and Central West regions of the country. To better understand the dimensions of herbicide resistance, in this chapter, we will explore the size of agricultural activity in Brazil, the pesticide market and the use of herbicides in the main crops. In addition, the agronomic, scientific-technical and economic aspects that have contributed, directly or indirectly, to the selection of resistant weeds will be discussed in order to have an overview of the economic impact of herbicide resistance management.


Author(s):  
Alysha T Torbiak ◽  
Robert Blackshaw ◽  
Randall N Brandt ◽  
Bill Hamman ◽  
Charles M. Geddes

Kochia [<i>Bassia scoparia</i> (L.) A.J. Scott] is a summer-annual tumbleweed that is tolerant of heat, drought and salinity, and capable of causing large yield losses in spring wheat (<i>Triticum aestivum</i> L). Increased incidence of glyphosate and acetolactate synthase (ALS) inhibitor-resistant kochia in Western Canada warrants investigation of alternative herbicides to manage these biotypes. Herbicides applied pre- or post-emergence in spring wheat were evaluated based on crop tolerance and control of ALS inhibitor-resistant kochia accessions with and without the glyphosate resistance trait in five environments near Lethbridge and Coalhurst, Alberta, from 2013-2015. The most effective and consistent treatments for kochia management included sulfentrazone applied pre-emergence, and fluroxypyr/bromoxynil/2,4-D or pyrasulfotole/bromoxynil applied post-emergence. All of these treatments resulted in ≥ 90% visible control in all environments and ≥ 90% kochia biomass reduction compared with the untreated control in Lethbridge 2014 and 2015. MCPA/dichlorprop-p/mecoprop-p, dicamba/2,4-D/mecoprop-p, and dicamba/fluroxypyr resulted in acceptable control among environments (≥ 80% visible control in all environments and ≥ 80% kochia biomass reduction in Lethbridge 2014 and 2015); however the latter two options caused unacceptable (> 10%) wheat visible injury in Coalhurst 2014. Recent confirmations of auxinic herbicide-resistant kochia in Western Canada – due, in part, to use of synthetic auxins to manage glyphosate-resistant kochia in small-grain cereals – will limit kochia management options. When implemented with non-chemical tools as part of an integrated weed management program, alternative herbicide modes of action like protoporphyrinogen oxidase inhibitors before and photosystem II or 4-hydroxyphenylpyruvate dioxygenase inhibitor(s) within spring wheat could mitigate selection for multiple herbicide-resistant kochia.


Weed Science ◽  
2021 ◽  
pp. 1-25
Author(s):  
Qian Yang ◽  
Xia Yang ◽  
Zichang Zhang ◽  
Jieping Wang ◽  
Weiguo Fu ◽  
...  

Abstract Barnyardgrass (Echinochloa crus-galli) is a noxious grass weed which infests rice fields and causes huge crop yield losses. In this study, we collected twelve E. crus-galli populations from rice fields of Ningxia province in China and investigated the resistance levels to acetolactate synthase (ALS) inhibitor penoxsulam and acetyl-CoA carboxylase (ACCase) inhibitor cyhalofop-butyl. The results showed that eight populations exhibited resistance to penoxsulam and four populations evolved resistance to cyhalofop-butyl. Moreover, all of the four cyhalofop-butyl-resistant populations (NX3, NX4, NX6 and NX7) displayed multiple-herbicide-resistance (MHR) to both penoxsulam and cyhalofop-butyl. The alternative herbicides bispyribac-sodium, metamifop and fenoxaprop-P-ethyl cannot effectively control the MHR plants. To characterize the molecular mechanisms of resistance, we amplified and sequenced the target-site encoding genes in resistant and susceptible populations. Partial sequences of three ALS genes and six ACCase genes were examined. A Trp-574-Leu mutation was detected in EcALS1 and EcALS3 in two high-level (65.84- and 59.30-fold) penoxsulam-resistant populations NX2 and NX10, respectively. In addition, one copy (EcACC4) of ACCase genes encodes a truncated aberrant protein due to a frameshift mutation in E. crus-galli populations. None of amino acid substitutions that are known to confer herbicide resistance were detected in ALS and ACCase genes of MHR populations. Our study reveals the widespread of multiple-herbicide resistant E. crus-galli populations at Ningxia province of China that exhibit resistance to several ALS and ACCase inhibitors. Non-target-site based mechanisms are likely to be involved in E. crus-galli resistance to the herbicides, at least in four MHR populations.


2010 ◽  
Vol 11 (1) ◽  
pp. 32 ◽  
Author(s):  
Christian A. Wyenandt ◽  
Steven L. Rideout ◽  
Beth K. Gugino ◽  
Margaret T. McGrath ◽  
Kathryne L. Everts ◽  
...  

Foliar diseases and fruit rots occur routinely on tomato, an important crop grown throughout the Mid-Atlantic and Northeast regions of the United States where it is produced for both fresh-market and processing. To enable these tomato growers to more effectively manage economically important diseases, a fungicide resistance management table has been developed which promotes the importance of understanding FRAC (Fungicide Resistance Action Committee) codes and provides an integrated pest management tool for tomato growers which will allow them to develop season-long disease control programs with an emphasis on fungicide resistance management. Accepted for publication 19 July 2010. Published 27 August 2010.


2017 ◽  
Vol 31 (3) ◽  
pp. 470-476 ◽  
Author(s):  
James T. Brosnan ◽  
Jose J. Vargas ◽  
Gregory K. Breeden ◽  
Sarah L. Boggess ◽  
Margaret A. Staton ◽  
...  

Methiozolin is an isoxazoline herbicide being investigated for selective POST annual bluegrass control in managed turfgrass. Research was conducted to evaluate methiozolin efficacy for controlling two annual bluegrass phenotypes with target-site resistance to photosystem II (PSII) or enolpyruvylshikimate-3-phosphate synthase (EPSPS)-inhibiting herbicides (i.e., glyphosate), as well as phenotypes with multiple resistance to microtubule and EPSPS or PSII and acetolactate synthase (ALS)-inhibiting herbicides. All resistant phenotypes were established in glasshouse culture along with a known herbicide-susceptible control and treated with methiozolin at 0, 125, 250, 500, 1000, 2000, 4000, or 8000 g ai ha−1. Methiozolin effectively controlled annual bluegrass with target-site resistance to inhibitors of EPSPS, PSII, as well as multiple resistance to EPSPS and microtubule inhibitors. Methiozolin rates required to reduce aboveground biomass of these resistant phenotypes 50% (GR50 values) were not significantly different from the susceptible control, ranging from 159 to 421 g ha−1. A phenotype with target-site resistance to PSII and ALS inhibitors was less sensitive to methiozolin (GR50=862 g ha−1) than a susceptible phenotype (GR50=423 g ha−1). Our findings indicate that methiozolin is an effective option for controlling select annual bluegrass phenotypes with target-site resistance to several herbicides.


2020 ◽  
Vol 7 (4) ◽  
pp. 55-62
Author(s):  
MUHAMMAD IQBAL ◽  
MUHAMMAD YASIR ◽  
ATIF JAVED ◽  
SARMAD TAUSIF

The current pot trial was conducted to estimate the impacts of different types of biochar on the growth and nutrients availability of maize (Zea mays) and their effects on the properties of soil. Treatments including four different feedstock based biochar i.e wheat straw, rice husk, corn cob and wood bark were applied to the soil in 10 kg pots @ 1.5% w/w. The experiment was carried out using complete randomized design (CRD). The crop was harvested after the plants have completed their vegetative growth. Physiological parameters of the crop (plant height, leaf area, chlorophyll content) were measured before harvesting while shoot mass (fresh and dry) and root mass (fresh and dry) were calculated after harvesting of the crop. The data showed a significant difference when compared with the control. Plant height was significantly increased from 140cm (control) to 159.9cm in T4 (wood bark biochar). Experimental soil was analyzed in the laboratory for NPK, water aggregate stability, organic matter and active carbon. Wet aggregate stability value of the soil was improved from 17.82% to 19.5%. Similarly soil active carbon was significantly improved from 259.33 ppm to 321.25 ppm. The data showed more significant results of wood bark biochar. Nutrient availability in the soil and plant nutrients uptake N (21.6%), P (31.25%) and K (45%) was increased as a results of biochar incorporation in the soil.


Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 605-612 ◽  
Author(s):  
Xiangying Liu ◽  
Shihai Xiang ◽  
Tao Zong ◽  
Guolan Ma ◽  
Lamei Wu ◽  
...  

AbstractThe widespread, rapid evolution of herbicide-resistant weeds is a serious and escalating agronomic problem worldwide. During China’s economic boom, the country became one of the most important herbicide producers and consumers in the world, and herbicide resistance has dramatically increased in the past decade and has become a serious threat to agriculture. Here, following an evidence-based PRISMA (preferred reporting items for systematic reviews and meta-analyses) approach, we carried out a systematic review to quantitatively assess herbicide resistance in China. Multiple weed species, including 26, 18, 11, 9, 5, 5, 4, and 3 species in rice (Oryza sativa L.), wheat (Triticum aestivum L.), soybean [Glycine max (L.) Merr.], corn (Zea mays L.), canola (Brassica napus L.), cotton (Gossypium hirsutum L.)., orchards, and peanut (Arachis hypogaea L.) fields, respectively, have developed herbicide resistance. Acetolactate synthase inhibitors, acetyl-CoA carboxylase inhibitors, and synthetic auxin herbicides are the most resistance-prone herbicides and are the most frequently used mechanisms of action, followed by 5-enolpyruvylshikimate-3-phosphate synthase inhibitors and protoporphyrinogen oxidase inhibitors. The lack of alternative herbicides to manage weeds that exhibit cross-resistance or multiple resistance (or both) is an emerging issue and poses one of the greatest threats challenging the crop production and food safety both in China and globally.


1999 ◽  
Vol 13 (3) ◽  
pp. 636-642 ◽  
Author(s):  
Chris M. Boerboom

Herbicide-resistant weeds are becoming a major problem in the Midwest, and strategies must be adopted to delay further selection. Strategies of rotating and tank-mixing herbicides with different modes of actions should be effective, but adoption may be limited and certain limitations may exist. Therefore, integrating nonchemical practices that indirectly lower selection pressure or restrict the growth of resistant populations is desirable. Appropriate integration of mechanical weeding, crop rotation, increased crop competition, and decision aids may further delay the development of resistance. Understanding the effect of these practices on weed population dynamics is required to more accurately predict their contributions toward resistance management. This knowledge will aid in justifying the adoption of improved management systems.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M. DILIPKUMAR ◽  
N.R. BURGOS ◽  
T.S. CHUAH ◽  
S. ISMAIL

ABSTRACT: The Clearfield® rice production system is an effective management tool for weedy rice and other weeds in the direct-seeded rice culture. However, if farmers cultivating the Clearfield® rice disregard stewardship recommendations, the industry could face a problem of herbicide-resistant weedy rice which would occur through the selection of outcrosses. This study aimed to confirm imidazolinone-resistant weedy rice in Malaysia. The resistant weedy rice (R-WR) was found to be 67 fold more resistant to OnDuty® (premix of imazapic and imazapyr) than the susceptible weedy rice (S-WR) based on the GR50 values (rate that causes 50% inhibition of shoot growth). The Clearfield® rice cultivar was 32-fold more tolerant to OnDuty® than the S-WR. Furthermore, the R-WR was 54 and 89 fold more resistant to imazapic and imazapyr applied separately than the S-WR, respectively. The Clearfield® rice was 140- and 40-fold more tolerant to imazapic and imazapyr, respectively than the S-WR. The R-WR biotype was susceptible to non-selective herbicides glyphosate and glufosinate, as well as the selective graminicide quizalofop. Oxadiazon controlled the R-WR biotype, but pretilachlor was ineffective. The present study documented the first case of weedy rice that was cross-resistant to imazapic and imazapyr in Malaysian Clearfield® rice field.


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