Weed Problems in Uruguayan Agriculture: Evolution and Current Situation

2021 ◽  
Vol 32 (5) ◽  
pp. 203-207
Author(s):  
M. Alejandro Garcia ◽  
Lucia V. Meneses ◽  
Tiago Edu Kaspary
Keyword(s):  
Weed Management ◽  
Agricultural Production ◽  
Production Systems ◽  
Integrated Weed Management ◽  
Zero Tillage ◽  
Weed Species ◽  
Management Tools ◽  
Herbicide Resistant ◽  
Species Frequencies ◽  
Agricultural Production Systems

Uruguayan agriculture has undergone dramatic changes in the last 50 years driven by the adoption of new agricultural production systems that incorporate zero tillage and herbicide resistant crops. This has resulted in a shift in weed species frequencies and the dispersion of introduced herbicide resistant weed populations. Finally, integrated weed management tools are being developed by research and extension services to manage herbicide-resistant (HR) weeds better and to reduce environmental impact of herbicides.

A holistic carrot production system for season-long weed management

2020 ◽  
Vol 34 (6) ◽  
pp. 876-881
Author(s):  
Jed B. Colquhoun ◽  
Richard A. Rittmeyer ◽  
Daniel J. Heider
Keyword(s):  
Weed Management ◽  
Production System ◽  
Production Systems ◽  
Foliar Application ◽  
Weed Species ◽  
Crop Failure ◽  
Management Tools ◽  
Canopy Development ◽  
Weed Density ◽  
Industry Standard

AbstractWeed management in carrot is challenging, given slow and inconsistent crop emergence and early-season growth and the lack of practical season-long management tools such as herbicides. We investigated holistic carrot production systems with a focus on minimizing inputs while optimizing resource use. In an overall sense, results of this work were consistent between years, and stark. The choice of carrot variety had a moderate influence on carrot foliar canopy development and, subsequently, weed density. For example, ‘Cupar’ carrot formed a complete crop canopy sooner than the other dicer-type ‘Canada’ variety. Likely as a result, density of weed species such as spotted ladysthumb and common lambsquarters was less where ‘Cupar’ was grown compared with where ‘Canada’ was grown. Gibberellic acid as a foliar application was not successful in these studies and, in a few cases, may have even increased weed-seed germination and establishment. Adding two carrot rows to the current regional industry-standard three-row bed system not only enhanced competitiveness with weeds but also improved carrot yield without additional fertilizer, water, or pest management inputs. By far, though, the most successful strategy to reduce weed density while maintaining or improving carrot yield was to delay seeding by 17 to 19 d. We anticipate more holistic production system research that integrates low-input alternatives in other crops as herbicide-resistant weeds proliferate while few new herbicides are developed. As was demonstrated in this research, such novel approaches can be successful without adding significant economic burden to the farmer or increasing risk of crop failure.

scholarly journals Diverse Approaches to Herbicide-Resistant Weed Management

Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 570-584 ◽  
Author(s):  
Micheal D. K. Owen
Keyword(s):  
Weed Management ◽  
Crop Production ◽  
Production Systems ◽  
Cost Effective ◽  
Developed Countries ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Cost Effective Method ◽  
Evolution Of Resistance ◽  
Complexity Cost

Herbicides have been the principal means of weed control in developed countries for approximately 50 yr because they are the most cost-effective method. Such general use of herbicides has resulted in weed resistance to herbicides, which continues to be a growing problem. Within the past decade, the evolution of resistance to the once-dominant herbicide glyphosate has resulted in major concerns about the future ability to control weeds in many crop systems. Moreover, many weed species have evolved resistance to multiple mechanisms of herbicide action. Given the dearth of new herbicides with novel mechanisms of action, it appears inevitable that weed management programs will need to be supplemented by the use of tactics other than herbicides. However, the inclusion of more diversity for weed management also introduces complexity, cost, and time constraints to current crop production systems. This paper describes broadly the considerations, opportunities, and constraints of diverse weed management tactics to address the burgeoning problems with herbicide resistance.

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.

Economics of integrated weed management in herbicide-resistant canola

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 138-147 ◽  
Author(s):  
Bharat M. Upadhyay ◽  
Elwin G. Smith ◽  
G. W. Clayton ◽  
K. N. Harker ◽  
R. E. Blackshaw
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Production Systems ◽  
Statistical Significance ◽  
Integrated Weed Management ◽  
Seeding Rate ◽  
Herbicide Resistant ◽  
Leaf Stage ◽  
Weed Removal

Integrated weed management (IWM) decision strategies in herbicide-resistant canola-production systems were assessed for net returns and relative risk. Data from two field experiments conducted during 1998 to 2000 at two locations in Alberta, Canada, were evaluated. A herbicide-based experiment included combinations of herbicide system (glufosinate-, glyphosate-, and imazethapyr-resistant canola varieties), herbicide rate (50 and 100% of recommended dose), and time of weed removal (two-, four-, and six-leaf stages of canola). A seed-based experiment included canola variety (hybrid and open-pollinated), seeding rate (100, 150, and 200 seeds m−2), and time of weed removal (two-, four-, and six-leaf stages of canola). For the herbicide-based experiment, strategies with glyphosate were profitable at Lacombe, but both imazethapyr and glyphosate strategies were profitable at Lethbridge. Weed control at the four-leaf stage was at least as profitable as the two-leaf stage at both sites. For the seed-based experiment, the hybrid was more profitable than the open-pollinated cultivar, seed rates of 100 and 150 seeds m−2were more profitable than 200 seeds m−2, and weed control at the two- and four-leaf stages was more profitable than at the six-leaf stage. When risk of returns and statistical significance was considered, several strategies were included in the risk-efficient set for risk-averse and risk-neutral attitudes at each location. However, the glyphosate-resistant cultivar, the 50% herbicide rate, and weed control at four-leaf stage were more frequent in the risk-efficient IWM strategy set. The open-pollinated cultivar, 200 seeds m−2rate, and weed control at the six-leaf stage were less frequent in the set. The risk-efficient sets of IWM strategies were consistent across a range of canola prices.

Herbicide-Resistant Weeds: Management Tactics and Practices

2006 ◽  
Vol 20 (3) ◽  
pp. 793-814 ◽  
Author(s):  
Hugh J. Beckie
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Management Practices ◽  
Cropping Systems ◽  
Integrated Weed Management ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Application Rates ◽  
Selection For ◽  
Reactive Management

In input-intensive cropping systems around the world, farmers rarely proactively manage weeds to prevent or delay the selection for herbicide resistance. Farmers usually increase the adoption of integrated weed management practices only after herbicide resistance has evolved, although herbicides continue to be the dominant method of weed control. Intergroup herbicide resistance in various weed species has been the main impetus for changes in management practices and adoption of cropping systems that reduce selection for resistance. The effectiveness and adoption of herbicide and nonherbicide tactics and practices for the proactive and reactive management of herbicide-resistant (HR) weeds are reviewed. Herbicide tactics include sequences and rotations, mixtures, application rates, site-specific application, and use of HR crops. Nonherbicide weed-management practices or nonselective herbicides applied preplant or in crop, integrated with less-frequent selective herbicide use in diversified cropping systems, have mitigated the evolution, spread, and economic impact of HR weeds.

Conyza bonariensis (flax-leaf fleabane) resistant to both glyphosate and ALS inhibiting herbicides innorth-eastern Victoria

2020 ◽  
Vol 71 (9) ◽  
pp. 864
Author(s):  
Charlotte Aves ◽  
John Broster ◽  
Leslie Weston ◽  
Gurjeet S. Gill ◽  
Christopher Preston
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Production Systems ◽  
Integrated Weed Management ◽  
Weed Species ◽  
Multiple Production ◽  
Conyza Bonariensis ◽  
Eastern Australia ◽  
North Eastern ◽  
Resistance To Herbicides

Conyza bonariensis (L.) Cronq. (syn. of Erigeron bonariensis L.) is a difficult-to-control summer weed species in the cropping belt of south-eastern Australia. Herbicide resistance may be affecting the ability to control C. bonariensis in the agricultural region of north-eastern Victoria; therefore, a survey was conducted to evaluate resistance to herbicides from several mode-of-action groups. Of the populations collected, 40% were resistant to glyphosate at 1080 g ha–1. Chlorsulfuron failed to control any of the populations collected. Further research identified multiple herbicide resistance to glyphosate, chlorsulfuron, metsulfuron-methyl and sulfometuron-methyl in five of nine populations fully characterised. Resistance was not found to 2,4-D, clopyralid or paraquat. There was no correlation between prevailing land use and the frequency of glyphosate-resistant populations, suggesting that resistance had been selected in multiple production systems. The high frequency of resistance could explain the difficulty experienced in controlling C. bonariensis across north-eastern Victoria and demonstrates the importance of integrated weed management to manage this weed.

scholarly journals Herbicide-resistant weeds in turfgrass: current status and emerging threats

2020 ◽  
Vol 34 (3) ◽  
pp. 424-430
Author(s):  
James T. Brosnan ◽  
Matthew T. Elmore ◽  
Muthukumar V. Bagavathiannan
Keyword(s):  
United States ◽  
Herbicide Resistance ◽  
Production Systems ◽  
The United States ◽  
Target Site ◽  
Current Status ◽  
Weed Species ◽  
Management Tools ◽  
Herbicide Resistant ◽  
Target Site Resistance

AbstractHerbicide-resistant weeds pose a severe threat to sustainable vegetation management in various production systems worldwide. The majority of the herbicide resistance cases reported thus far originate from agronomic production systems where herbicide use is intensive, especially in industrialized countries. Another notable sector with heavy reliance on herbicides for weed control is managed turfgrass systems, particularly golf courses and athletic fields. Intensive use of herbicides, coupled with a lack of tillage and other mechanical tools that are options in agronomic systems, increases the risk of herbicide-resistant weeds evolving in managed turfgrass systems. Among the notable weed species at high risk for evolving resistance under managed turf systems in the United States are annual bluegrass, goosegrass, and crabgrasses. The evolution and spread of multiple herbicide resistance, an emerging threat facing the turfgrass industry, should be addressed with the use of diversified management tools. Target-site resistance has been reported commonly as a mechanism of resistance for many herbicide groups, though non–target site resistance is an emerging concern. Despite the anecdotal evidence of the mounting weed resistance issues in managed turf systems, the lack of systematic and periodic surveys at regional and national scales means that confirmed reports are very limited and sparse. Furthermore, currently available information is widely scattered in the literature. This review provides a concise summary of the current status of herbicide-resistant weeds in managed turfgrass systems in the United States and highlights key emerging threats.

Management of Pigweed (Amaranthusspp.) in Glufosinate-Resistant Soybean in the Midwest and Mid-South

2016 ◽  
Vol 30 (2) ◽  
pp. 355-365 ◽  
Author(s):  
Thomas R. Butts ◽  
Jason K. Norsworthy ◽  
Greg R. Kruger ◽  
Lowell D. Sandell ◽  
Bryan G. Young ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Production Systems ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Weed Species ◽  
Seeding Rate ◽  
Row Width ◽  
Narrow Row ◽  
Sites Of Action

Pigweeds are among the most abundant and troublesome weed species across Midwest and mid-South soybean production systems because of their prolific growth characteristics and ability to rapidly evolve resistance to several herbicide sites of action. This has renewed interest in diversifying weed management strategies by implementing integrated weed management (IWM) programs to efficiently manage weeds, increase soybean light interception, and increase grain yield. Field studies were conducted across 16 site-years to determine the effectiveness of soybean row width, seeding rate, and herbicide strategy as components of IWM in glufosinate-resistant soybean. Sites were grouped according to optimum adaptation zones for soybean maturity groups (MGs). Across all MG regions, pigweed density and height at the POST herbicide timing, and end-of-season pigweed density, height, and fecundity were reduced in IWM programs using a PRE followed by (fb) POST herbicide strategy. Furthermore, a PRE fb POST herbicide strategy treatment increased soybean cumulative intercepted photosynthetically active radiation (CIPAR) and subsequently, soybean grain yield across all MG regions. Soybean row width and seeding rate manipulation effects were highly variable. Narrow row width (≤ 38 cm) and a high seeding rate (470,000 seeds ha−1) reduced end-of-season height and fecundity variably across MG regions compared with wide row width (≥ 76 cm) and moderate to low (322,000 to 173,000 seeds ha−1) seeding rates. However, narrow row widths and high seeding rates did not reduce pigweed density at the POST herbicide application timing or at soybean harvest. Across all MG regions, soybean CIPAR increased as soybean row width decreased and seeding rate increased; however, row width and seeding rate had variable effects on soybean yield. Furthermore, soybean CIPAR was not associated with end-of-season pigweed growth and fecundity. A PRE fb POST herbicide strategy was a necessary component for an IWM program as it simultaneously managed pigweeds, increased soybean CIPAR, and increased grain yield.

Differential germination response of Navua sedge (Cyperus aromaticus) populations to environmental factors

Weed Science ◽  
2021 ◽  
pp. 1-24
Author(s):  
Bhagirath S. Chauhan
Keyword(s):  
Weed Management ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Weed Species ◽  
Management Tools ◽  
Perennial Weed ◽  
Tropical Regions ◽  
Seed Biology ◽  
Cyperus Aromaticus ◽  
Flooding Depth

Abstract Navua sedge (Cyperus aromaticus) is a hard to control C4 perennial weed species in tropical regions of Australia. Knowledge of its seed biology could help to develop integrated weed management programs for this species. This study was conducted in laboratory and screenhouse conditions to evaluate the effect of alternating day/night temperatures, light, pretreatment high temperatures, burial depth, and flooding depth on the germination and emergence of two populations (Ingham and Tablelands) of C. aromaticus. Both populations germinated at temperatures ranging from 20/10 to 35/25 C; however, the Ingham population germination (76%) was greater than the Tablelands population (42%) at the highest temperature regime (35/25 C). None of the populations germinated at 15/5 C. Darkness completely inhibited germination in both populations, suggesting that the seeds are positively photoblastic. Seeds (dry and wet) of both populations germinated after exposure to pretreatment temperatures of up to 100 C for 5 min. After pretreatment at 150 C, only the Ingham population germinated, and the germination of dry seeds (62%) was greater than wet seeds (1%). None of the populations germinated after the exposure to 200 C. For both populations, maximum germination was observed for seeds at 0 cm, and a burial depth of 0.5 cm completely inhibited emergence of the Tablelands population and 2.0 cm inhibited germination of the Ingham population. A flooding depth of 10 cm greatly reduced emergence in both populations compared with 0 cm (62 and 78%) but 12 to 14% of seedlings still emerged, suggesting the need to integrate flooding with other management tools. The results also suggest that the Ingham population may have a greater potential to spread into new areas or become more invasive than the Tablelands population. Knowledge gained from this study can be used to manage C. aromaticus by fire/burning, tillage, and flooding.

Prospects for the development of agrarian production systems in in the Right Bank Polesie of Ukraine

2018 ◽  
Vol 2 (95) ◽  
pp. 69-72
Author(s):  
Yu.A. Tarariko ◽  
L.V. Datsko ◽  
M.O. Datsko
Keyword(s):  
Agricultural Production ◽  
Production Systems ◽  
Economic Feasibility ◽  
Capital Investments ◽  
Resource Potential ◽  
Grain Processing ◽  
Processing And Storage ◽  
The Right ◽  
And Storage ◽  
Agricultural Production Systems

The aim of the work is to assess the existing and prospective models for the development of agricultural production in Central Polesie on the basis of economic feasibility and ecological balance. The evaluation of promising agricultural production systems was carried out with the help of simulation modeling of various infrastructure options at the levels of crop and multisectoral specialization of agroecosystems. The agro-resource potential of Central Polesie is better implemented in the rotation with lupine, corn and flax dolguntsem with well-developed infrastructure, including crop, livestock units, grain processing and storage systems, feed, finished products and waste processing in the bioenergetic station. The expected income for the formation of such an infrastructure is almost 8 thousand dollars. / with a payback period of capital investments of 2-3 years.

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