Survey of rice weed management and public and private consultant characteristics in Southern Brazil

2019 ◽  
Vol 34 (3) ◽  
pp. 351-356 ◽  
Author(s):  
Bruno de Lima Fruet ◽  
Aldo Merotto ◽  
André da Rosa Ulguim
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Management Practices ◽  
Resistance Management ◽  
Weedy Rice ◽  
Herbicide Application ◽  
Public And Private ◽  
Rice Farmers ◽  
Survey Results ◽  
Imidazolinone Herbicides

AbstractIdentification of common weeds is fundamental in determining adequate recommendations for management practices. The aim of this study was to identify the patterns of weed management adopted by rice farmers and the perspectives of consultants who work in flooded rice areas in Rio Grande do Sul (RS) State, Brazil. Fifty-three public and 50 private consultants who worked with rice in RS in 2017 and 2018 were interviewed. Data were analyzed by descriptive statistics. Both weedy rice and Echinochloa sp. occurred and escaped more often from chemical control because they remained in the field until harvest in 59% of the area. According to consultants, the main reasons for reduced weed control were related to herbicide resistance and late herbicide application. Fifty-six percent of farmers used imidazolinone herbicides at rates that were greater than those indicated on the label for POST application. The consultants’ main challenges were weed escapes, resistance management, and guidelines on herbicide rates. Survey results show that the use of herbicide rates above label recommendations and consultants’ work on control of weed escapes are directly related to the high occurrence of herbicide resistance.

Assessing Fitness Costs from a Herbicide-Resistance Management Perspective: A Review and Insight

Weed Science ◽  
2018 ◽  
Vol 67 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Eshagh Keshtkar ◽  
Roohollah Abdolshahi ◽  
Hamidreza Sasanfar ◽  
Eskandar Zand ◽  
Roland Beffa ◽  
...  
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Genetic Background ◽  
Management Practices ◽  
Evolutionary Ecology ◽  
Resistance Management ◽  
Single Population ◽  
Herbicide Resistant ◽  
Scientific Disciplines ◽  
Cost Studies

AbstractIn recent years, herbicide resistance has attracted much attention as an increasingly urgent problem worldwide. Unfortunately, most of that effort was focused on confirmation of resistance and characterization of the mechanisms of resistance. For management purposes, knowledge about biology and ecology of the resistant weed phenotypes is critical. This includes fitness of the resistant biotypes compared with the corresponding wild biotypes. Accordingly, fitness has been the subject of many studies; however, lack of consensus on the concept of fitness resulted in poor experimental designs and misinterpretation of the ensuing data. In recent years, methodological protocols for conducting proper fitness studies have been proposed; however, we think these methods should be reconsidered from a herbicide-resistance management viewpoint. In addition, a discussion of the inherent challenges associated with fitness cost studies is pertinent. We believe that the methodological requirements for fitness studies of herbicide-resistant weed biotypes might differ from those applied in other scientific disciplines such as evolutionary ecology and genetics. Moreover, another important question is to what extent controlling genetic background is necessary when the aim of a fitness study is developing management practices for resistant biotypes. Among the methods available to control genetic background, we suggest two approaches (single population and pedigreed lines) as the most appropriate methods to detect differences between resistant (R) and susceptible (S) populations and to derive herbicide-resistant weed management programs. Based on these two methods, we suggest two new approaches that we named the “recurrent single population” and “recurrent pedigreed lines” methods. Importantly, whenever the aim of a fitness study is to develop optimal resistance management, we suggest selecting R and S plants within a single population and evaluating all fitness components from seed to seed instead of measuring changes in the frequency of R and S alleles through multigenerational fitness studies.

Managing herbicide resistance in China

Weed Science ◽  
2020 ◽  
pp. 1-14
Author(s):  
Xiangying Liu ◽  
Austin Merchant ◽  
Shihai Xiang ◽  
Tao Zong ◽  
Xuguo Zhou ◽  
...  
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Management Practices ◽  
Management Strategies ◽  
Resistance Management ◽  
Acetolactate Synthase ◽  
Developed Countries ◽  
The United States ◽  
Resistance Mechanisms ◽  
Future Research

Abstract Since its initial introduction in the late 1950s, chemical control has dominated weed management practices in China. Not surprisingly, the development of herbicide resistance has become the biggest threat to long-term, sustainable weed management in China. Given that China has followed the same laissez-faire approach toward resistance management that has been practiced in developed countries such as the United States, herbicide resistance has evolved rapidly and increased steadily over the years. Previously, we carried out a systematic review to quantitatively assess herbicide-resistance issues in China. In this review, our main objective is to focus on mechanistic studies and management practices to document the (1) history of herbicide application in China; (2) resistance mechanisms governing the eight most resistance-prone herbicide groups, including acetolactate synthase inhibitors, acetyl-CoA carboxylase inhibitors, synthetic auxin herbicides, 5-enolpyruvylshikimate-3-phosphate synthase inhibitors, protoporphyrinogen oxidase inhibitors, photosystem I electron diverters, photosystem II inhibitors, and long-chain fatty-acid inhibitors; and (3) herbicide-resistance management strategies commonly used in China, including chemical, cultural, biological, physical, and integrated approaches. At the end, perspectives and future research are discussed to address the pressing need for the development of integrated herbicide-resistance management in China.

scholarly journals Fitness of Herbicide-Resistant Weeds: Current Knowledge and Implications for Management

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 469 ◽  
Author(s):  
Vila-Aiub
Keyword(s):  
Life History ◽  
Herbicide Resistance ◽  
Management Practices ◽  
Current Knowledge ◽  
Resistance Management ◽  
Fitness Cost ◽  
Plant Fitness ◽  
Resistance Mutations ◽  
Fitness Costs ◽  
Wide Range

Herbicide resistance is the ultimate evidence of the extraordinary capacity of weeds to evolve under stressful conditions. Despite the extraordinary plant fitness advantage endowed by herbicide resistance mutations in agroecosystems under herbicide selection, resistance mutations are predicted to exhibit an adaptation cost (i.e., fitness cost), relative to the susceptible wild-type, in herbicide untreated conditions. Fitness costs associated with herbicide resistance mutations are not universal and their expression depends on the particular mutation, genetic background, dominance of the fitness cost, and environmental conditions. The detrimental effects of herbicide resistance mutations on plant fitness may arise as a direct impact on fitness-related traits and/or coevolution with changes in other life history traits that ultimately may lead to fitness costs under particular ecological conditions. This brings the idea that a “lower adaptive value” of herbicide resistance mutations represents an opportunity for the design of resistance management practices that could minimize the evolution of herbicide resistance. It is evident that the challenge for weed management practices aiming to control, minimize, or even reverse the frequency of resistance mutations in the agricultural landscape is to “create” those agroecological conditions that could expose, exploit, and exacerbate those life history and/or fitness traits affecting the evolution of herbicide resistance mutations. Ideally, resistance management should implement a wide range of cultural practices leading to environmentally mediated fitness costs associated with herbicide resistance mutations.

Survey on weedy rice (Oryza spp.) management practice and adoption of Clearfield® rice technology in Peninsular Malaysia

Weed Science ◽  
2021 ◽  
pp. 1-7
Author(s):  
Masilamany Dilipkumar ◽  
Muhammad Saiful Ahmad-Hamdani ◽  
Hairazi Rahim ◽  
Tse Seng Chuah ◽  
Nilda Roma Burgos
Keyword(s):  
Agricultural Development ◽  
Management Practices ◽  
Management Practice ◽  
Educational Programs ◽  
Peninsular Malaysia ◽  
Weedy Rice ◽  
Rice Farmers ◽  
Development Area ◽  
Adoption Level ◽  
Main Factor

Abstract A total of 452 rice farmers from three main granary areas of Muda Agricultural Development Authority (MADA), Kemubu Agricultural Development Authority (KADA), and Integrated Agricultural Development Area Barat Laut Selangor (IADA BLS) were surveyed in 2019. The goal was to determine farmers’ knowledge of and management practices for weedy rice (Oryza spp.) as well as the adoption level of Clearfield® rice technology (CRT) in Malaysia. Most farmers (74%) were adept at recognizing weedy rice. The majority of farmers (77%) perceived transplanting and water seeding rice systems as the best options to manage weedy rice, while only 10% of the farmers adopted CRT. The low level of adoption of this technology was due to several constraints, including the high cost of the CRT package and occurrence of imidazolinone (IMI)-resistant weedy rice in their farms. Farmers from MADA and IADA BLS reported the occurrence of IMI weedy rice in their farms for more than nine planting seasons, whereas those from KADA reported having resistant weedy rice for five to six planting seasons. The main factor contributing to the evolution of IMI-resistant weedy rice was ignorance about the technology and deliberate disregard of stewardship guidelines. The survey revealed that there is a need to increase awareness about CRT through training and educational programs for proper adoption of this technology.

scholarly journals Sensitivity of imidazolinone-resistant red rice (Oryza sativa L.) to glyphosate and glufosinate

2015 ◽  
Vol 45 (9) ◽  
pp. 1557-1563 ◽  
Author(s):  
Guilherme Vestena Cassol ◽  
Luis Antonio de Avila ◽  
Carla Rejane Zemolin ◽  
Andrey Piveta ◽  
Dirceu Agostinetto ◽  
...  
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Oryza Sativa L ◽  
Dry Weight ◽  
Integrated Weed Management ◽  
Rio Grande Do Sul ◽  
Red Rice ◽  
Resistance Evolution ◽  
Logistic Analysis ◽  
Imidazolinone Herbicides

<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>

Weed management practices in glyphosate-tolerant and conventional cotton fields in Australia

2006 ◽  
Vol 46 (9) ◽  
pp. 1177 ◽  
Author(s):  
J. A. Werth ◽  
C. Preston ◽  
G. N. Roberts ◽  
I. N. Taylor
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Herbicide Application ◽  
Resistance Development ◽  
Roundup Ready ◽  
Use Patterns ◽  
Management Techniques ◽  
Cotton Fields ◽  
Herbicide Use

Forty growers in 4 major cotton-growing regions in Australia were surveyed in 2003 to investigate how the adoption of glyphosate-tolerant cotton (Roundup Ready) had influenced herbicide use, weed management techniques, and whether changes to the weed spectrum could be identified. The 10 most common weeds reported on cotton fields were the same in glyphosate-tolerant and conventional fields in this survey. Herbicide use patterns were altered by the adoption of glyphosate-tolerant cotton with up to 6 times more glyphosate usage, but 21% fewer growers applying pre-emergence herbicides in glyphosate-tolerant fields. Other weed control practices such as the use of post-emergence herbicides, inter-row cultivation and hand hoeing were only reduced marginally. However, growers indicated that management practices are likely to change over time, especially with the introduction of enhanced glyphosate tolerance technology (Roundup Ready Flex), and anticipate a 32% decrease in the number of growers using alternative weed management practices. To date, management practices other than glyphosate use have not changed markedly in glyphosate-tolerant cotton indicating a conservative approach by growers adopting this technology and reflecting the narrow window of herbicide application. The range of weed control options still being employed in glyphosate-tolerant cotton would not increase the risk of glyphosate resistance development.

Growth ofKochia scoparia, Salsola iberica, andTriticum aestivumvaries with temperature

Weed Science ◽  
1999 ◽  
Vol 47 (4) ◽  
pp. 435-439 ◽  
Author(s):  
Cathy A. Nord ◽  
Calvin G. Messersmith ◽  
John D. Nalewaja
Keyword(s):  
Weed Management ◽  
Growth Response ◽  
Management Practices ◽  
Fresh Weight ◽  
Herbicide Application ◽  
Kochia Scoparia ◽  
Optimum Time ◽  
Influence Of Temperature On ◽  
Response To Temperature ◽  
Salsola Iberica

Information on the influence of temperature on growth of springTriticum aestivumL. (wheat) relative toKochia scoparia(L.) Schrad. (kochia) andSalsola ibericaSennen and Pau (Russian thistle) could lead to more efficient weed management practices. An experiment was conducted to determine the growth of springT. aestivum, K. scoparia, andS. ibericaat 15, 23, and 30 C in growth chambers. Fresh weight at 15 C was greater for springT. aestivumthan forK. scopariaandS. iberica.Conversely, fresh weights at 23 or 30 C were greater forK. scopariaandS. ibericathan for springT. aestivum.Growth response to temperature is consistent with the physiological characteristics for photosynthesis of springT. aestivum, a C3plant, andK. scopariaandS. iberica, which are C4plants. The results indicate that cool temperatures that usually occur for early-seeded springT. aestivumwould give springT. aestivumthe competitive advantage overK. scopariaorS. iberica.Additionally, growing degree day (GDD) equations for height development ofK. scopariaandS. ibericawere determined and could be used to determine the optimum time for postemergence herbicide application.

scholarly journals A New Approach to Weed Management to Mitigate Herbicide Resistance in Argentina

Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 641-648 ◽  
Author(s):  
Claudio Rubione ◽  
Sarah M. Ward
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Integrated Weed Management ◽  
National Committee ◽  
Weed Species ◽  
Corn Production ◽  
Public And Private ◽  
Herbicide Resistant ◽  
Crop Varieties ◽  
Export Taxes

The evolution of herbicide-resistant weeds is a major concern in the corn- and soybean-producing Pampas region of Argentina, where growers predominantly plant glyphosate-resistant crop varieties and depend heavily on glyphosate for weed control. Currently, 16 weed species in Argentina are resistant to one or more of three different herbicide mechanisms of action, and resistant weed populations continue to increase, posing a serious threat to agricultural production. Implementation of integrated weed management to address herbicide resistance faces significant barriers in Argentina, especially current land ownership and rental patterns in the Pampas. More than 60% of Pampas cropland is rented to tenants for periods that rarely exceed 1 yr, resulting in crop rotation being largely abandoned, and crop export taxes and quotas have further discouraged wheat and corn production in favor of continuous soybean production. In this paper we discuss ways to facilitate new approaches to weed management in Argentina, including legal and economic reforms and the formation of a national committee of stakeholders from public and private agricultural sectors.

scholarly journals Labor-Saving Weed Technologies for Lowland Rice Farmers in sub-Saharan Africa

2015 ◽  
Vol 29 (4) ◽  
pp. 751-757 ◽  
Author(s):  
Jonne Rodenburg ◽  
Kazuki Saito ◽  
Runyambo Irakiza ◽  
Derek W. Makokha ◽  
Enos A. Onyuka ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sub Saharan Africa ◽  
Herbicide Application ◽  
Control Efficacy ◽  
Rice Farmers ◽  
Time Requirements ◽  
Rice Yields ◽  
Sub Saharan ◽  
Hand Weeding

Time requirements, weed control efficacy, and yield effects of three labor-saving weed technologies were tested against hand weeding during three seasons in 2012 and 2013. The technologies included two hand-operated mechanical weeders, the straight-spike and the twisted-spike floating weeder, and the PRE application of oxadiazon. The straight-spike floating weeder reduced weeding time by 32 to 49%, the twisted-spike floating weeder reduced weeding time by 32 to 56%, and the application of herbicide required 88 to 97% less time than hand weeding. Herbicide application provided the best weed control in two of the three seasons. No differences in weed control efficacy were observed between mechanical and hand weeding. Yield differences were only observed in season 3 with higher rice yields after PRE application of oxadiazon compared with other weed management treatments.

scholarly journals Economic Barriers to Herbicide-Resistance Management

Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 585-594 ◽  
Author(s):  
Terrance M. Hurley ◽  
George Frisvold
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Resistance Management ◽  
Common Goal ◽  
Multifaceted Approach ◽  
Herbicide Resistant ◽  
Biological Perspective ◽  
Economic Barriers ◽  
Near Term

Herbicide-resistant weeds are the result of evolutionary processes that make it easy to think about the problem from a purely biological perspective. Yet, the act of weed management, guided by human production of food and fiber, drives this biological process. Thus, the problem is socioeconomic as well as biological. The purpose of this article is to explain how well-known socioeconomic phenomena create barriers to herbicide-resistance management and highlight important considerations for knocking down these barriers. The key message is that the multidimensional problem requires a multifaceted approach that recognizes differences among farmers; engages the regulatory, academic, extension, seed and chemical suppliers, and farmer communities; and aligns the diverse interests of the members of these communities with a common goal that benefits all—more sustainable weed management. It also requires an adaptive approach that transitions from moreuniform and costly standards and incentives, which can be effective in the near-term but are unsustainable, to more-targeted and less-costly approaches that are sustainable in the long term.

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