Imazamox Plus Propanil Mixtures for Grass Weed Management in Imidazolinone-Resistant Rice

2016 ◽  
Vol 30 (1) ◽  
pp. 29-35 ◽  
Author(s):  
J. Caleb Fish ◽  
Eric P. Webster ◽  
David C. Blouin ◽  
Jason A. Bond

A study was established to evaluate interactions between imazamox at 0 and 44 g ai ha−1mixed with propanil at 0, 1,120, 2,240, 3,360, and 4,480 g ai ha−1for the control of red rice and barnyardgrass. Blouin's Modified Colby's procedure was used to test for interactions. At 7 d after treatment (DAT), a synergistic response occurred for red rice treated with imazamox at 44 g ha−1mixed with propanil at 3,360 and 4,480 g ha−1by increasing expected control of 62% to an observed control of 67 and 75%, respectively, and the synergistic response continued across all evaluations through 49 DAT. No antagonism occurred for any imazamox plus propanil mixture for red rice control. An antagonistic response was shown for barnyardgrass control with imazamox at 44 g ha−1mixed with any rate of propanil, at 7 DAT. However, imazamox plus propanil at 4,480 g ha−1resulted in a neutral response at 14 through 49 DAT. Rice treated with imazamox plus propanil at 4,480 g ha−1plus imazamox resulted in a yield of 6,640 kg ha−1. The synergistic response observed for red rice control with a mixture of imazamox plus propanil can benefit producers by increasing control of red rice, and this mixture contains two different modes of action that can be part of an overall resistance management strategy.

2015 ◽  
Vol 29 (4) ◽  
pp. 689-696 ◽  
Author(s):  
John Caleb Fish ◽  
Eric P. Webster ◽  
David C. Blouin ◽  
Jason A. Bond

A study was conducted to evaluate interactions of imazethapyr co-application with propanil, thiobencarb, or a prepackaged mixture of propanil plus thiobencarb. At 7, 14, 21, and 49 d after treatment (DAT), synergism occurred for red rice treated with imazethapyr at 70 g ai ha−1mixed with propanil plus thiobencarb at 1,680 and 3,360 g ai ha−1. A synergistic response was also observed with imazethapyr at 70 g ha−1mixed with propanil at 1,680 g ha−1; however, all other co-applications evaluated resulted in a neutral response with no antagonism observed. At 7 DAT, antagonism was observed for barnyardgrass when treated with imazethapyr at 70 g ha−1mixed with propanil plus thiobencarb at 1,680 g ha−1, propanil at 840 g ha−1, or thiobencarb at 840 and 1,680 g ha−1; however, a synergistic response occurred for barnyardgrass control at 14, 21, and 49 DAT with imazethapyr at 70 g ha−1mixed with propanil plus thiobencarb at 3,360 g ha−1. The synergistic response observed for red rice and barnyardgrass control with a mixture of imazethapyr plus propanil plus thiobencarb can benefit producers by increasing control of red rice and barnyardgrass, and this mixture contains three herbicides with three different modes of action, which can be part of an overall resistance-management strategy in imidazolinone-resistant (IR) rice.


2006 ◽  
Vol 20 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Bryan G. Young

Recent shifts in herbicide use patterns can be attributed to rapid, large-scale adoption of glyphosate-resistant soybean and cotton. A dramatic increase in glyphosate use is the most obvious change associated with the adoption of glyphosate-resistant crops. Consequently, the diversity of herbicides used for weed management in these crops has declined, particularly in soybean. To date, the availability of glyphosate-resistant corn has limited the use of glyphosate in corn. While exploiting the benefits of glyphosate-resistant crops, many growers have abandoned the principles of sound weed and herbicide-resistance management. Instead of incorporating glyphosate into a resistance management strategy utilizing multiple herbicide sites of action, many growers rely exclusively upon glyphosate for weed control. Although it is difficult to establish a clear relationship between the adoption of glyphosate-resistant crops and changes in other crop production practices, the increase in no-till and strip-till production of cotton and soybean between 1995 and 2002 may have been facilitated by glyphosate-resistant crops.


Weed Science ◽  
2020 ◽  
Vol 68 (2) ◽  
pp. 179-185
Author(s):  
Chun Liu ◽  
Paul Neve ◽  
Les Glasgow ◽  
R. Joseph Wuerffel ◽  
Micheal D. K. Owen ◽  
...  

AbstractDiversity is key for sustainable weed management and can be achieved via both chemical and nonchemical control tactics. Genetically modified crops with two-way or three-way stacked herbicide-tolerant traits allow use of herbicide mixtures that would otherwise be phytotoxic to the crop. Early weed management (EWM) strategies promote the use of PRE herbicides with residual activity to keep the field free of weeds early in the season for successful crop establishment. To evaluate the respective sustainability and practicality of the two chemical-based management tactics (i.e., stacked traits and EWM), we used a population model of waterhemp, Amaranthus tuberculatus (Moq.) Sauer (syn. rudis), to simulate the evolution of resistance in this key weed species in midwestern U.S. soybean [Glycine max (L.) Merr.] agroecosystems. The model tested scenarios with a varying number of herbicide sites of action (SOAs), application timings (PRE and POST), and preexisting levels of resistance. Results showed that both tactics provided opportunity for controlling resistant A. tuberculatus populations. In general, each pass over the field should include at least two effective herbicide SOAs. Nevertheless, the potential evolution of cross-resistance may void the weed control programs embraced by stacked traits and diverse herbicide SOAs. Economic calculations suggested that the diversified programs could double long-term profitability when compared to the conventional system, because of improved yield and grain quality. Ultimately, the essence of a sustainable herbicide resistance management strategy is to be proactive. Although a herbicide-dominated approach to diversifying weed management has been prevalent, the increasing presence of weed populations with multiple resistance means that finding herbicides to which weed populations are still susceptible is becoming increasingly difficult, and thus the importance of reintroducing cultural and mechanical practices to support herbicides must be recognized.


2021 ◽  
Vol 32 (4) ◽  
pp. 151-157
Author(s):  
Raven A. Bough ◽  
Phillip Westra ◽  
Todd A. Gaines ◽  
Eric P. Westra ◽  
Scott Haley ◽  
...  

The authors discuss the importance of wheat as a global food source and describe a novel multi-institutional, public-private partnership between Colorado State University, the Colorado Wheat Research Foundation, and private chemical and seed companies that resulted in the development of a new herbicide-resistant wheat production system.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
H.K. TAKANO ◽  
R.S. OLIVEIRA JR. ◽  
J. CONSTANTIN ◽  
V.F.V. SILVA ◽  
R.R. MENDES

ABSTRACT: The use of mixtures and rotation of herbicide modes of action are essential for herbicide resistance management. The purpose of this research was to evaluate different pre- and post-emergence herbicides to control goosegrass in soybean and corn. Four greenhouse experiments were conducted, one in pre-emergence and the three others in post-emergence. In pre-emergence, the number of emerged plants and the control percentage at 20, 35 and 50 days after application were evaluated. In post-emergence, the control percentage was evaluated at 14 and 28 days after application on plants with one tiller and four tillers. The use of residual herbicides to control glyphosate-resistant goosegrass is a very important tool for its effective management. The application stage is also crucial for post-emergence efficacy. Paraquat and [paraquat + diuron] are effective in controlling this species. The application of ACCase inhibiting herbicides alone seems to be more effective than their associations with glyphosate, especially in plants with four tillers. HPPD inhibiting herbicides have high synergism with atrazine and not with glyphosate.


2015 ◽  
Vol 45 (9) ◽  
pp. 1557-1563 ◽  
Author(s):  
Guilherme Vestena Cassol ◽  
Luis Antonio de Avila ◽  
Carla Rejane Zemolin ◽  
Andrey Piveta ◽  
Dirceu Agostinetto ◽  
...  

<p>Dose-response experiments were carried out to evaluate the sensitivity of imidazolinone-resistant red rice to nonselective herbicides currently used in rice-soybean rotation in Rio Grande do Sul. Two red rice biotypes previously identified as resistant and susceptible to the imidazolinone herbicides were treated with imazapic plus imazapic, glyphosate and glufosinate under nine herbicide rates. A non-linear log-logistic analysis was used to estimate the herbicide rate that provided 50% red rice control and dry weight reduction (GR<sub>50</sub>). Imidazolinone-resistant red rice exhibited greater GR<sub>50</sub> values than imidazolinone-susceptible biotype for imazapyr plus imazapic. In contrast, both imidazolinone-resistant and susceptible red rice showed similar GR<sub>50</sub>values for glyphosate and glufosinate. These results indicate that glyphosate and glufosinate effectively control imidazolinone-resistant red rice at similar herbicide rates used to control imidazolinone-susceptible; however, integrated weed management practices must be adopted in rice-soybean rotation to delay resistance evolution of red rice populations to glyphosate and glufosinate</p>


2014 ◽  
Vol 104 (12) ◽  
pp. 1264-1273 ◽  
Author(s):  
Frank van den Bosch ◽  
Neil Paveley ◽  
Femke van den Berg ◽  
Peter Hobbelen ◽  
Richard Oliver

We have reviewed the experimental and modeling evidence on the use of mixtures of fungicides of differing modes of action as a resistance management tactic. The evidence supports the following conclusions. 1. Adding a mixing partner to a fungicide that is at-risk of resistance (without lowering the dose of the at-risk fungicide) reduces the rate of selection for fungicide resistance. This holds for the use of mixing partner fungicides that have either multi-site or single-site modes of action. The resulting predicted increase in the effective life of the at-risk fungicide can be large enough to be of practical relevance. The more effective the mixing partner (due to inherent activity and/or dose), the larger the reduction in selection and the larger the increase in effective life of the at-risk fungicide. 2. Adding a mixing partner while lowering the dose of the at-risk fungicide reduces the selection for fungicide resistance, without compromising effective disease control. The very few studies existing suggest that the reduction in selection is more sensitive to lowering the dose of the at-risk fungicide than to increasing the dose of the mixing partner. 3. Although there are very few studies, the existing evidence suggests that mixing two at-risk fungicides is also a useful resistance management tactic. The aspects that have received too little attention to draw generic conclusions about the effectiveness of fungicide mixtures as resistance management strategies are as follows: (i) the relative effect of the dose of the two mixing partners on selection for fungicide resistance, (ii) the effect of mixing on the effective life of a fungicide (the time from introduction of the fungicide mode of action to the time point where the fungicide can no longer maintain effective disease control), (iii) polygenically determined resistance, (iv) mixtures of two at-risk fungicides, (v) the emergence phase of resistance evolution and the effects of mixtures during this phase, and (vi) monocyclic diseases and nonfoliar diseases. The lack of studies on these aspects of mixture use of fungicides should be a warning against overinterpreting the findings in this review.


2019 ◽  
Vol 33 (03) ◽  
pp. 464-474
Author(s):  
Tessa de Boer ◽  
Peter Smith ◽  
Kevin Chandler ◽  
Robert Nurse ◽  
Kristen Obeid ◽  
...  

AbstractThe development of a linuron-free weed management strategy for carrot production is essential as a result of the herbicide reevaluation programs launched by the Pest Management Regulatory Agency in Canada for herbicides registered before 1995 and the discovery of linuron-resistant pigweed species in Ontario. Field trials were conducted in one of Ontario’s main carrot-growing regions on high organic soils in 2016 and 2017. Pigweed species seedlings were effectively controlled with PRE treatments of prometryn, pendimethalin, S-metolachlor, or glufosinate. POST treatments of pyroxasulfone and metribuzin followed by predetermined biologically effective dose (≥90% control of pigweed seedlings) of acifluorfen, oxyfluorfen, fluthiacet-methyl, and fomesafen achieved excellent crop selectivity and commercially acceptable pigweed species seedling control under field conditions. Carfentrazone-ethyl or fomesafen applied PRE severely reduced seedling emergence and yield in the wet growing season of 2017. This study demonstrated clearly that an alternative linuron-free strategy can be developed for carrots. The strategy of exploring the potential to use the biologically effective dose of selected herbicides to achieve crop selectivity and control of pigweed species seedlings was verified.


Heredity ◽  
2020 ◽  
Vol 124 (5) ◽  
pp. 621-632 ◽  
Author(s):  
Magellan Tchouakui ◽  
Jacob Riveron Miranda ◽  
Leon M. J. Mugenzi ◽  
Doumani Djonabaye ◽  
Murielle J. Wondji ◽  
...  

Abstract Metabolic resistance threatens the sustainability of pyrethroid-based malaria control interventions. Elucidating the fitness cost and potential reversal of metabolic resistance is crucial to design suitable resistance management strategies. Here, we deciphered the fitness cost associated with the CYP6P9a (P450-mediated metabolic resistance) in the major African malaria vector Anopheles funestus. Reciprocal crosses were performed between a pyrethroid susceptible (FANG) and resistant (FUMOZ-R) laboratory strains and the hybrid strains showed intermediate resistance. Genotyping the CYP6P9a-R resistance allele in oviposited females revealed that CYP6P9a negatively impacts the fecundity as homozygote susceptible mosquitoes (CYP6P9a-SS) lay more eggs than heterozygote (OR = 2.04: P = 0.01) and homozygote resistant mosquitoes. CYP6P9a also imposes a significant fitness cost on the larval development as homozygote resistant larvae (CYP6P9a-RR) developed significantly slower than heterozygote and homozygote susceptible mosquitoes (χ2 = 11.2; P = 0.0008). This fitness cost was further supported by the late pupation of homozygote resistant than susceptible mosquitoes (OR = 2.50; P < 0.01). However, CYP6P9a does not impact the longevity as no difference was observed in the life span of mosquitoes with different genotypes (χ2 = 1.6; P = 0.9). In this hybrid strain, a significant decrease of the resistant CYP6P9a-RR genotype was observed after ten generations (χ2 = 6.6; P = 0.01) suggesting a reversal of P450-based resistance in the absence of selection. This study shows that the P450-mediated metabolic resistance imposes a high fitness cost in malaria vectors supporting that a resistance management strategy based on rotation could help mitigate the impact of such resistance.


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