Glyphosate as a Tool for the Incorporation of New Herbicide Options in Integrated Weed Management in Maize: A Weed Dynamics Evaluation

A farm-scale investigation was conducted to evaluate the potential impact of integrating glyphosate into different weed management programs when cultivating herbicide-tolerant maize in central Spain from 2012 to 2014. The weed management programs were (1) a conventional weed management with pre- and post-emergent herbicide applications, (2) a weed management program in which the number and total amount of conventional herbicides applied were reduced, and (3) three weed management programs that comprised either two post-emergent applications of the herbicide glyphosate, or only one glyphosate application combined with pre- and/or post-emergent herbicides. Weed density throughout each cropping season was greater in those weed management programs that did not include a pre-emergence application of herbicides than those that did. Moreover, none of the weed management programs affected the richness and species diversity of the weeds or reduced yields. Although the impact of the different programs was similar in terms of weed species diversity, the composition of the weed community differed and this effect must be considered when providing agroecosystem services. Our results indicate that glyphosate-tolerant maize provides an additional tool that allows integrated weed control of the weed populations without reducing yields.

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Effect of Barley Sowing Density on the Integrated Weed Management of Lolium rigidum (Annual Ryegrass) in Mediterranean Dryland: A Modeling Approach

Agronomy ◽

10.3390/agronomy11081565 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1565

Author(s):

María Belén D’Amico ◽

Guillermo R. Chantre ◽

Guillermo L. Calandrini ◽

José L. González-Andújar

Keyword(s):

Weed Management ◽

Life Cycles ◽

Integrated Weed Management ◽

Future Research ◽

Seed Removal ◽

Weed Infestation ◽

High Control ◽

Weed Dynamics ◽

The Impact

Population models are particularly helpful for understanding long-term changes in the weed dynamics associated with integrated weed management (IWM) strategies. IWM practices for controlling L. rigidum are of high importance, mainly due to its widespread resistance that precludes chemical control as a single management method. The objective of this contribution is to simulate different IWM scenarios with special emphasis on the impact of different levels of barley sowing densities on L. rigidum control. To this effect, a weed–crop population model for both L. rigidum and barley life cycles was developed. Our results point out: (i) the necessity of achieving high control efficiencies (>99%), (ii) that the increase of twice the standard sowing density of barley resulted in a reduction of 23.7% of the weed density, (iii) non-herbicide-based individual methods, such as delayed sowing and weed seed removal at harvest, proved to be inefficient for reducing drastically weed population, (iv) the implementation of at least three control tactics (seed removal, delay sowing and herbicides) is required for weed infestation eradication independently of the sowing rate, and (v) the effect of an increase in the sowing density is diluted as a more demanding weed control is reached. Future research should aim to disentangle the effect of different weed resistance levels on L. rigidum population dynamics and the required efficiencies for more sustainable IWM programs.

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Influence of integrated weed management on weed dynamics and productivity of chili

Journal of AgriSearch ◽

10.21921/jas.5.3.2 ◽

2018 ◽

Vol 5 (03) ◽

Author(s):

RP JAISWAL ◽

DHANANJAI SINGH ◽

AK NAIDU

Keyword(s):

Weed Management ◽

Chenopodium Album ◽

Weed Suppression ◽

Yield Enhancement ◽

Integrated Weed Management ◽

Weed Species ◽

Ripe Fruit ◽

Paddy Straw ◽

Weed Dynamics ◽

Dry Fruit

A field experiment was carried out at Vegetable Research Farm, Mahrajpur, Department of Horticulture, JNKVV, Jabalpur (M.P.) to study the efficacy of different herbicides and mulches against weeds in chili, It was recorded that dominant weed flora in the experiment was Eragrostis cillansis and Cyperus rotindus among monocot weeds, Chenopodium album, Melilotus alba, Anagallis aruensis and Parthenium hysterophorus among dicot weeds. Highest weed density of all the weed species, dry weed biomass were recorded in weedy check plots. Pendimethalin @ 1.5 l/ha + black polythene mulch resulted in the highest plant height (75.3 cm), number of primary branches per plant (15.66), number of fruits per plant (73.33), yield of red ripe fruit (134.7q/ha-1) and yield of dry fruit (22qha-1) followed by Pendimethalin @ 1.5 l/ha + paddy straw mulch. Therefore, pendimethalin @ 1.5 l/ha + black polythene mulch resulted in the most effective treatment in terms of weed suppression and yield enhancement of chili crop.

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Influence of Cereal Rye Management on Weed Control in Soybean

Frontiers in Agronomy ◽

10.3389/fagro.2020.600568 ◽

2020 ◽

Vol 2 ◽

Author(s):

Kurt M. Vollmer ◽

Mark J. VanGessel ◽

Quintin R. Johnson ◽

Barbara A. Scott

Keyword(s):

Weed Control ◽

Weed Management ◽

Cover Crop ◽

Management Program ◽

Weed Suppression ◽

Integrated Weed Management ◽

Weed Species ◽

Delayed Effect ◽

Cereal Rye ◽

Winter Annual

Cereal rye as a cover crop is often used to improve soil health and as part of integrated weed management programs. Despite this, cereal rye biomass is often not managed for optimal weed suppression. This study evaluated the effects of managing cereal rye as part of an integrated weed management strategy in soybean. Factors consisted of levels of cereal rye management (no cereal rye, no nitrogen, or 20 kg/ha of nitrogen); cereal rye termination timing (20 or 10 d before soybean planting); and residual herbicide treatment applied at cereal rye termination (with or without). Winter annual weed control with cereal rye was generally greater compared to no cereal rye. Winter annual weed control was consistently better when cereal rye was terminated at 20 d before soybean planting compared to 10 d; while summer annual weed control was improved if termination was delayed. Effect of cereal rye management on summer annual weed control varied by weed species. In the absence of residual herbicides, Palmer amaranth control responded to the different levels of cereal rye management. However, morningglory spp. only responded to rye with supplemental N applications. Large crabgrass control was similar for treatments containing cereal rye, regardless of nitrogen input. Our results demonstrate the importance of cover crop management when incorporating cereal rye into an integrated weed management program for soybean.

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Fertilizer placement affects growth and reproduction of three common weed species in pine bark–based soilless nursery substrates

Weed Science ◽

10.1017/wsc.2019.49 ◽

2019 ◽

Vol 67 (6) ◽

pp. 682-688 ◽

Cited By ~ 1

Author(s):

Debalina Saha ◽

S. Christopher Marble ◽

Nelmaris Torres ◽

Annette Chandler

Keyword(s):

Weed Management ◽

Management Program ◽

Alternative Methods ◽

Integrated Weed Management ◽

Weed Species ◽

Fertilizer Placement ◽

Tropical Plants ◽

Weed Growth ◽

Eclipta Prostrata ◽

Growth And Reproduction

AbstractWeed management in container crops is primarily accomplished through frequent PRE herbicide applications and supplemental hand weeding. However, many ornamental species are sensitive to herbicides, and a significant number of tropical plants, ornamental grasses, and foliage crops have not been screened for herbicide tolerance. As nursery crops are produced in inert substrates that are largely composed of bark or peat, strategic fertilizer placement has the potential to significantly reduce weed growth in container-grown ornamentals. Growth and reproduction of three common container nursery weed species, eclipta [Eclipta prostrata (L.) L.], large crabgrass [Digitaria sanguinalis (L.) Scop.], and spotted spurge (Euphorbia maculata L.), were evaluated following fertilization via alternative methods, including subdressing or dibbling in comparison with industry standard practices of topdressing or incorporating a controlled-release fertilizer (17-5-11 [8 to 9 mo.]) to each 3.8-L container at 36.5 g per container. Fertilizer placement had little to no effect on germination of Eclipta prostrata or D. sanguinalis, but incorporation increased E. maculata germination by 77% to 183% compared with other placements or a nonfertilized control. Subdressing reduced seed production by 94%, 63%, and 92% for Eclipta prostrata, D. sanguinalis, and E. maculata, respectively, compared with the average number of seeds produced in the conventional placement methods (average of incorporation and topdressing). Dibbling fertilizer resulted in similar decreases in the case of D. sanguinalis and E. maculata, while Eclipta prostrata produced no seeds when fertilizer was dibbled. Similar to reductions observed in reproduction, subdressing fertilizer resulted in biomass decreases of 90%, 81%, and 85% compared with the average biomass of the incorporation and topdressed placements. Results suggest alternative fertilizer placements could be implemented as part of an integrated weed management program in container production to reduce weed growth.

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Herbicide resistant weeds: the case of resistance to glyphosate

Vietnam Journal of Science Technology and Engineering ◽

10.31276/vjste.63(2).74-80 ◽

2021 ◽

Vol 63 (2) ◽

pp. 74-80

Author(s):

The Duc Ngo ◽

Keyword(s):

Weed Management ◽

Glyphosate Resistance ◽

Resistance Mechanisms ◽

Management Program ◽

Ambrosia Artemisiifolia ◽

Target Site ◽

Integrated Weed Management ◽

Weed Species ◽

Site Mutation ◽

Sites Of Action

Glyphosate has become the most widely used herbicide worldwide since 1974 with a global use of 8.6 billion kg (glyphosate active ingredient) between 1974 and 2014. This study reports on glyphosate resistant (GR) weeds and their resistance mechanisms based on global scientifically reported cases. Forty-nine different weed species have evolved resistance to glyphosate in 29 countries with a total of 318 identified cases worldwide. Fifty percent of these resistance cases were found in glyphosate-resistant cropping systems. There were 255 identified cases (80.2%) of glyphosate resistance in the top five countries (in terms of number of cases and species), namely USA, Australia, Argentina, Brazil, and Canada. The five most popular weed species (in terms of number of cases) found to be resistant to glyphosate were Conyza canadensis, Amaranthus palmeri, Amaranthus tuberculatus, Lolium perenne ssp. Multiflorum,and Ambrosia artemisiifolia with 42, 42, 29, 26, and 21 reported cases, respectively. Out of 49 weed species, 19 GR weed species were found to not only be resistant to glyphosate but also to other herbicide sites of action (multiple herbicide resistance). Glyphosate resistance mechanisms in weeds include (1) target-site alterations: target-site mutation and target-site gene amplification; and (2) non-target-site mechanisms involving different modes of exclusion from the target site: reduced glyphosate uptake, reduced glyphosate translocation, and enhanced glyphosate metabolism. It is essential to have an integrated weed management program that includes not only smart herbicide mixtures and rotations, but also cultural, manual, mechanical, and crop-based weed management methods.

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Integrated weed management and weed species diversity

Phytoprotection ◽

10.7202/706048ar ◽

2005 ◽

Vol 75 (1) ◽

pp. 1-18 ◽

Cited By ~ 86

Author(s):

D.R. Clements ◽

S.F. Weise ◽

C.J. Swanton

Keyword(s):

Species Diversity ◽

Weed Management ◽

Community Dynamics ◽

Crop Yields ◽

Integrated Weed Management ◽

Weed Species ◽

Community Interactions ◽

Natural Systems ◽

Weed Diversity ◽

Alternative Practices

Alternative practices for weed management, such as integrated weed management (IWM) may allow the persistence of weed populations below a given economic threshold. Increased species diversity of weeds also may result. If diversity increases, and the number of ecological interactions also increases, weed species should be viewed as an interactive community, rather than an unrelated set of targets for control. In this review we summarize how diversity is evaluated in unmanaged Systems, examine how IWM techniques may alter the diversity of weed species and suggest how strategies can be developed for managing weed diversity under IWM. Methods used to evaluate diversity in natural Systems may be used to evaluate weed diversity in alternative Systems of weed management. We made preliminary calculations of diversity for reduced tillage, modified herbicide use, crop rotation, critical period of weed control, techniques to improve crop competitiveness, and alternative control methods. Many of these IWM techniques potentially may result in changes in weed species diversity. We examined potential effects of these changes in weed diversity within six primary elements of community ecology: colonization, disturbance, the physical environment, interactions with other communities, community interactions and community dynamics. Opportunities to develop strategies of community management exist within each of these elements. If diversity could be managed while maintaining acceptable crop yields, some previously unrealized benefits of the presence of weeds could be seen, as predicted by relationships among plants of unmanaged communities. Moreover, the goal of producing a more sustainable System that incorporates the diversity of the weed community would be complemented by trends in policy towards encouraging biodiversity in agroecosystems.

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Variation in postdispersal weed seed predation in a crop field

Weed Science ◽

10.1614/ws-05-075r.1 ◽

2006 ◽

Vol 54 (1) ◽

pp. 148-155 ◽

Cited By ~ 56

Author(s):

Helen Spafford Jacob ◽

David M. Minkey ◽

Robert S. Gallagher ◽

Catherine P. Borger

Keyword(s):

Seed Predation ◽

Weed Management ◽

General Pattern ◽

Management Program ◽

Integrated Weed Management ◽

Seed Removal ◽

Weed Seed ◽

Management Options ◽

Cropping Season ◽

Oat Seeds

Postdispersal weed seed predation by animals during the summer fallow period may lead to a reduction in the number of weeds that grow in the following winter cropping season. In this study, we investigated the patterns of weed seed removal, the influence of crop residue cover on seed removal, the types of granivores present and their seed preferences in a 16-ha postharvest cropping field in Western Australia during the summer months over 2 yr. Seed removal from caches was extremely variable (from 0 to 100%). Removal rates were generally highest along the edges of the field near bordering vegetation and lowest in the center of the field and within the bordering vegetation. However, there were many deviations from this general pattern. There was no change in rates of predation with different levels of residue cover. Ants or other small invertebrates were found to remove the most seeds. However, seed removal by other animals, such as rodents, was also evident. Annual ryegrass seeds were preferred over wild oat seeds, followed by wild radish pod segments. Seed harvesting was lowest in late January, peaked in February, and decreased in March. Results from this study suggest seed harvesters could reduce the number of surface seeds in the field, reducing the weed seed bank. Management options that increase the activity of the seed harvesters may lead to less variability in seed predation and could, therefore, be incorporated into an integrated weed management program.

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Germination Biology of Sesbania (Sesbania cannabina): An Emerging Weed in the Australian Cotton Agro-environment

Weed Science ◽

10.1017/wsc.2018.62 ◽

2018 ◽

Vol 67 (1) ◽

pp. 68-76 ◽

Cited By ~ 2

Author(s):

Nadeem Iqbal ◽

Sudheesh Manalil ◽

Bhagirath S. Chauhan ◽

Steve W. Adkins

Keyword(s):

Seed Germination ◽

Management Strategies ◽

Moisture Stress ◽

Integrated Weed Management ◽

Burial Depth ◽

Weed Species ◽

Physical Dormancy ◽

Sesbania Cannabina ◽

Wide Range ◽

The Impact

AbstractSesbania [Sesbania cannabina(Retz.) Pers.] is a problematic emerging weed species in Australian cotton-farming systems. However, globally, no information is available regarding its seed germination biology, and better understanding will help in devising superior management strategies to prevent further infestations. Laboratory and glasshouse studies were conducted to evaluate the impact of various environmental factors such as light, temperature, salt, osmotic and pH stress, and burial depth on germination and emergence of two Australian biotypes ofS. cannabina. Freshly harvested seeds of both biotypes possessed physical dormancy. A boiling-water scarification treatment (100±2 C) of 5-min duration was the optimum treatment to overcome this dormancy. Once dormancy was broken, the Dalby biotype exhibited a greater germination (93%) compared with the St George biotype (87%). The nondormant seeds of both biotypes showed a neutral photoblastic response to light and dark conditions, with germination marginally improved (6%) under illumination. Maximum germination of both biotypes occurred under an alternating temperature regime of 30/20 and 35/25 C and under constant temperatures of 32 or 35 C, with no germination at 8 or 11 C. Seed germination of both biotypes decreased linearly from 87% to 14% with an increase in moisture stress from 0.0 to −0.8 MPa, with no germination possible at −1.0 MPa. There was a gradual decline in germination for both biotypes when imbibed in a range of salt solutions of 25 to 250 mM, with a 50% reduction in germination occurring at 150 mM. Both biotypes germinated well under a wide range of pH values (4.0 to 10.0), with maximum germination (94%) at pH 9.0. The greatest emergence rate of the Dalby (87%) and St George (78%) biotypes was recorded at a burial depth of 1.0 cm, with no emergence at 16.0 cm. Deep tillage seems to be the best management strategy to stopS. cannabina’s emergence and further infestation of cotton (Gossypium hirsutumL.) fields. The findings of this study will be helpful to cotton agronomists in devising effective, sustainable, and efficient integrated weed management strategies for the control ofS. cannabinain cotton cropping lands.

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Weed Problems in Uruguayan Agriculture: Evolution and Current Situation

Outlooks on Pest Management ◽

10.1564/v32_oct_05 ◽

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.

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Halauxifen-methyl controls glyphosate-resistant horseweed (Conyza canadensis) but not giant ragweed (Ambrosia trifida) in winter wheat

Weed Technology ◽

10.1017/wet.2020.21 ◽

2020 ◽

Vol 34 (4) ◽

pp. 607-612 ◽

Cited By ~ 1

Author(s):

Jessica Quinn ◽

Nader Soltani ◽

Jamshid Ashigh ◽

David C. Hooker ◽

Darren E. Robinson ◽

...

Keyword(s):

Winter Wheat ◽

Weed Management ◽

Field Experiments ◽

The United States ◽

Integrated Weed Management ◽

Conyza Canadensis ◽

Limited Information ◽

Weed Species ◽

Ambrosia Trifida ◽

Giant Ragweed

AbstractHorseweed is a competitive summer or winter annual weed that produces up to 230,000 small seeds per plant that are capable of traveling more than 500 km via wind. Giant ragweed is a tall, highly competitive summer annual weed. Glyphosate-resistant (GR) horseweed and GR giant ragweed pose significant challenges for producers in the United States and Ontario, Canada. It is thought that an integrated weed management (IWM) system involving herbicide rotation is required to control GR biotypes. Halauxifen-methyl is a new selective broadleaf POST herbicide registered for use in cereal crops; there is limited information on its efficacy on horseweed and giant ragweed. The purpose of this research was to determine the efficacy of halauxifen-methyl applied POST, alone and in a tank mix, for the control of GR horseweed and GR giant ragweed in wheat across southwestern Ontario. For each weed species, an efficacy study consisting of six field experiments was conducted over a 2-yr period (2018, 2019). At 8 wk after application (WAA), halauxifen-methyl, fluroxypyr/halauxifen-methyl, fluroxypyr/halauxifen-methyl + MCPA EHE, fluroxypyr + MCPA ester, 2,4-D ester, clopyralid, and pyrasulfotole/bromoxynil + ammonium sulfate controlled GR horseweed >95%. Fluroxypyr and MCPA provided only 86% and 37% control of GR horseweed, respectively. At 8 WAA, fluroxypyr, fluroxypyr/halauxifen-methyl, fluroxypyr/halauxifen-methyl + MCPA EHE, fluroxypyr + MCPA ester, fluroxypyr/halauxifen-methyl + MCPA EHE + pyroxsulam, 2,4-D ester, clopyralid, and thifensulfuron/tribenuron + fluroxypyr + MCPA ester controlled GR giant ragweed 87%, 88%, 90%, 94%, 96%, 96%, 98%, and 93%, respectively. Halauxifen-methyl and pyroxsulam provided only 45% and 28% control of GR giant ragweed, respectively. Halauxifen-methyl applied alone POST in the spring controlled GR horseweed but not GR giant ragweed in winter wheat.

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