INTEGRAÇÃO DE PRÁTICAS PARA O MANEJO DE PLANTAS DANINHAS NA CULTURA DO MILHO

As práticas de manejo do solo e de culturas podem afetar diretamente a infestação de plantas daninhas na cultura do milho. O objetivo desse trabalho foi avaliar o efeito da integração de práticas culturais e químicas na infestação de plantas daninhas e na produtividade da cultura do milho. Foi conduzido um experimento em Papanduva, SC, em delineamento experimental de blocos ao acaso, com três repetições e parcelas subdivididas. Nas parcelas foram avaliados dois sistemas de manejo cultural de plantas daninhas: S1 (cultivo de consórcio de espécies para cobertura do solo no inverno, uso de sementes de milho com elevada massa e espaçamento entre fileiras de 0,45 m) e S2 (pousio no inverno, uso de sementes de milho com baixa massa e espaçamento entre fileiras de 0,90 m). Nas subparcelas foram avaliadas quatro estratégias de controle de plantas daninhas no milho (sem controle, atrazine, atrazine+mesotrione e capina). Avaliaram-se a quantidade de palha no momento da semeadura do milho, a velocidade de decomposição da palha, a densidade e a massa seca da parte aérea de plantas daninhas e o desempenho da cultura de milho. O uso de práticas culturais para o manejo de plantas daninhas promoveu redução da infestação dessas plantas na cultura de milho, além de aumentar a produtividade da cultura. A aplicação de atrazine + mesotrione proporcionou melhor controle de plantas daninhas e maior produtividade de grãos em relação à aplicação isolada de atrazine. ABSTRACT Soil and crop management can affect the weed population in corn. The experiment was carried out to evaluate the effect of cultural and chemical management practices on weed infestation and corn yield. The experiment was carried out in Papanduva, SC, Brazil. The experimental design was a randomized complete blocks with three replications in a split-plot arrangement. In plots were evaluated two cultural weed management systems: S1 (multicropping of winter cover crops, corn seeds with high weight and narrow row of 0.45 m) and S2 (winter fallow, corn seeds with low weight and narrow row of 0.90 m). In subplots were evaluated four weed control strategies (no-control, atrazine, atrazine + mesotrione and weeding). The parameters evaluated were the straw quantity, residue decomposition, weed plant density and shoot dry mass and corn performance. The use of cultural weed management practices reduced the weed infestation on corn and improved the crop yield. The association of atrazine + mesotrione herbicides showed more efficient weed control than atrazine.

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Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed (Conyza canadensis) Population Dynamics and Crop Yield-Years III and IV

Weed Science ◽

10.1614/ws-09-006.1 ◽

2009 ◽

Vol 57 (4) ◽

pp. 417-426 ◽

Cited By ~ 40

Author(s):

Vince M. Davis ◽

Kevin D. Gibson ◽

Thomas T. Bauman ◽

Stephen C. Weller ◽

William G. Johnson

Keyword(s):

Population Dynamics ◽

Crop Rotation ◽

Crop Yield ◽

Cover Crops ◽

Weed Management ◽

Management Practices ◽

Plant Density ◽

Crop Yields ◽

Management Systems ◽

No Till

Horseweed is an increasingly common and problematic weed in no-till soybean production in the eastern cornbelt due to the frequent occurrence of biotypes resistant to glyphosate. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual non-glyphosate herbicides, and preplant application timing on the population dynamics of glyphosate-resistant (GR) horseweed and crop yield. A field study was conducted from 2003 to 2007 in a no-till field located at a site that contained a moderate infestation of GR horseweed (approximately 1 plant m−2). The experiment was a split-plot design with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying in-field horseweed plant density, seedbank density, and crop yield. Horseweed densities were collected at the time of postemergence applications, 1 mo after postemergence (MAP) applications, and at the time of crop harvest or 4 MAP. Viable seedbank densities were also evaluated from soil samples collected in the fall following seed rain. Soybean–corn crop rotation reduced in-field and seedbank horseweed densities vs. continuous soybean in the third and fourth yr of this experiment. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season-long in-field horseweed densities and protecting crop yields since the growth habit of horseweed in this region is primarily as a summer annual. Management systems also influenced the GR and glyphosate-susceptible (GS) biotype population structure after 4 yr of management. The most dramatic shift was from the initial GR : GS ratio of 3 : 1 to a ratio of 1 : 6 after 4 yr of residual preplant herbicide use followed by non-glyphosate postemergence herbicides.

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Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed Population Dynamics and Crop Yield

Weed Science ◽

10.1614/ws-06-187.1 ◽

2007 ◽

Vol 55 (5) ◽

pp. 508-516 ◽

Cited By ~ 31

Author(s):

Vince M. Davis ◽

Kevin D. Gibson ◽

Thomas T. Bauman ◽

Stephen C. Weller ◽

William G. Johnson

Keyword(s):

Population Dynamics ◽

Crop Rotation ◽

Crop Yield ◽

Cover Crops ◽

Weed Management ◽

Management Practices ◽

Plant Density ◽

Management Systems ◽

Integrated Weed Management ◽

Rapid Decline

Horseweed is an increasingly problematic weed in soybean because of the frequent occurrence of glyphosate-resistant (GR) biotypes. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual nonglyphosate herbicides, and preplant herbicide application timing on the population dynamics of GR horseweed and crop yield. A field study was conducted at a site with a moderate infestation of GR horseweed (approximately 1 plant m−2) with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying horseweed plant density, seedbank density, and crop yield. Crop rotation did not influence in-field horseweed or seedbank densities at any data census timing. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season long horseweed densities and protecting crop yield because horseweed in this region behaves primarily as a summer annual weed. Horseweed seedbank densities declined rapidly in the soil by an average of 76% for all systems over the first 10 mo before new seed rain. Despite rapid decline in total seedbank density, seed for GR biotypes remained in the seedbank for at least 2 yr. Therefore, to reduce the presence of GR horseweed biotypes in a local no-till weed flora, integrated weed management (IWM) systems should be developed to reduce total horseweed populations based on the knowledge that seed for GR biotypes are as persistent in the seed bank as glyphosate-sensitive (GS) biotypes.

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Assessment of crop and weed management strategies prior to introduction of auxin-resistant crops in Brazil

Weed Technology ◽

10.1017/wet.2020.96 ◽

2020 ◽

pp. 1-11

Author(s):

Maxwel C. Oliveira ◽

Anelise Lencina ◽

André R. Ulguim ◽

Rodrigo Werle

Keyword(s):

Cover Crops ◽

Weed Management ◽

Management Practices ◽

Cropping Systems ◽

Control Strategies ◽

Management Strategies ◽

Acetolactate Synthase ◽

Weed Species ◽

Research Education ◽

No Till

Abstract A stakeholder survey was conducted from April through June of 2018 to understand stakeholders’ perceptions and challenges about cropping systems and weed management in Brazil. The dominant crops managed by survey respondents were soybean (73%) and corn (66%). Approximately 75% of survey respondents have grown or managed annual cropping systems with two to three crops per year cultivated in succession. Eighteen percent of respondents manage only irrigated cropping systems, and over 60% of respondents adopt no-till as a standard practice. According to respondents, the top five troublesome weed species in Brazilian cropping systems are horseweed (asthmaweed, Canadian horseweed, and tall fleabane), sourgrass, morningglory, goosegrass, and dayflower (Asiatic dayflower and Benghal dayflower). Among the nine species documented to have evolved resistance to glyphosate in Brazil, horseweed and sourgrass were reported as the most concerning weeds. Other than glyphosate, 31% and 78% of respondents, respectively, manage weeds resistant to acetyl-CoA carboxylase (ACCase) inhibitors and/or acetolactate synthase (ALS) inhibitors. Besides herbicides, 45% of respondents use mechanical, and 75% use cultural (e.g., no-till, crop rotation/succession) weed control strategies. Sixty-one percent of survey respondents adopt cover crops to some extent to suppress weeds and improve soil chemical and physical properties. Nearly 60% of survey respondents intend to adopt the crops that are resistant to dicamba or 2,4-D when available. Results may help practitioners, academics, industry, and policy makers to better understand the bad and the good of current cropping systems and weed management practices adopted in Brazil, and to adjust research, education, technologies priorities, and needs moving forward.

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201 ALTERNATIVE WEED CONTROL STRATEGIES FOR STRAWBERRIES IN THE ESTABLISHMENT YEAR

HortScience ◽

10.21273/hortsci.29.5.458a ◽

1994 ◽

Vol 29 (5) ◽

pp. 458a-458

Author(s):

Charlotte Herman ◽

Emily Hoover

Keyword(s):

Weed Control ◽

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Plant Material ◽

Control Strategies ◽

First Year ◽

Strawberry Plant ◽

Stage Of Development ◽

Alternative Weed Control

The objective of our study was to establish first year strawberry plantings without using herbicides. `Honeyoye' transplants were set into plots measuring 6.1m × 7.32m on 21 May, 1993. Four treatments were established: winter wheat, a dwarf Brassica sp., napropamide (2.24kg/h), and no weed management. After the strawberry plants, cover crops (and some weeds) were fairly well established, (18 June) 6 week-old African “weeder” geese were put into half of each plot to graze. Weekly data was taken on the percentage of soil area covered with plant material, height and stage of development of plants, and weeds present. A weed transect was done in 6 July. Plant material was collected from each plot on 26 July and 16 Sept. in a 0.2m2 area, and dried. The most promising cover crop treatment was the dwarf Brassica for early season weed control. However, the herbicide treatment with no geese produced the best strawberry plant growth.

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Influence of Management on Long-Term Seedbank Dynamics of Rigid Ryegrass (Lolium rigidum) in Cropping Systems of Southern Australia

Weed Science ◽

10.1614/ws-d-15-00119.1 ◽

2016 ◽

Vol 64 (2) ◽

pp. 303-311 ◽

Cited By ~ 12

Author(s):

Samuel G. L. Kleemann ◽

Christopher Preston ◽

Gurjeet S. Gill

Keyword(s):

Weed Control ◽

Weed Management ◽

Plant Density ◽

Cropping Systems ◽

Management Strategies ◽

Crop Productivity ◽

Field Pea ◽

Spike Density ◽

Weed Infestation ◽

Rigid Ryegrass

A field study was undertaken to investigate the influence of different management strategies on rigid ryegrass plant density and seedbank dynamics over 4 yr. Even though weed seedbank declined by 86% after oaten hay in year 1, the residual seedbank enabled rigid ryegrass to reinfest field peas the next year, and the population rebounded sharply when weed control relied solely on PPI trifluralin. However, use of POST clethodim followed by crop-topping for seed-set prevention of rigid ryegrass in field pea was highly effective and caused a further decline in the weed seedbank. Integration of effective management tactics over 3 yr significantly reduced rigid ryegrass weed and spike density (90 and 81%) in the final year of the 4-yr cropping sequence. Use of oaten hay in year 1, followed by effective weed control in field pea and wheat crops, depleted the high initial seedbank (4,820 seeds m−2) to moderate levels (< 200 seeds m−2) within 3 yr. Effective weed-management treatments depleted the rigid ryegrass seedbank, reduced in-crop weed infestation, and returned higher grain yields and profitability. The results of this study clearly show that large rigid ryegrass populations can be managed effectively without reducing crop productivity and profitability provided multiyear weed-management programs are implemented effectively.

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Integrating Reduced Herbicide Use with Mechanical Weeding in Corn (Zea mays)

Weed Technology ◽

10.1017/s0890037x00027779 ◽

1993 ◽

Vol 7 (2) ◽

pp. 382-389 ◽

Cited By ~ 57

Author(s):

Thomas A. Mulder ◽

Jerry D. Doll

Keyword(s):

Weed Control ◽

Weed Management ◽

Management Practices ◽

Field Research ◽

Integrated Weed Management ◽

Corn Yield ◽

Minimal Risk ◽

Economic Returns ◽

Growing Seasons ◽

Herbicide Use

Concern about the effects of pesticides on the environment and the desire to reduce purchased inputs are stimuli to reduce herbicide use. Field research was conducted at two locations for two growing seasons to identify integrated weed management practices in corn that are effective and economical. Weed control treatments included PRE application of a herbicide mixture of 1.8 kg ai ha−1of atrazine plus 2.2 kg ai ha−1of metolachlor alone, this mixture broadcast or band-applied at a reduced rate in combination with mechanical weeding, and mechanical weeding alone. Weed control, corn yield, and economic returns were generally higher in treatments combining herbicides and mechanical weeding than those using only mechanical measures. Without herbicides, timeliness of rotary hoeing was critical. Herbicide use can be reduced 50 to 75% in integrated systems with minimal risk of yield loss due to uncontrolled weeds.

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627 PB 457 RELAY-INTERPLANTING COVER CROPS IN SWEET CORN

HortScience ◽

10.21273/hortsci.29.5.522c ◽

1994 ◽

Vol 29 (5) ◽

pp. 522c-522

Author(s):

Tom TenPas ◽

John Luna

Keyword(s):

Zea Mays ◽

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Management Practices ◽

Sweet Corn ◽

Weed Competition ◽

Corn Yield ◽

Significant Yield ◽

Block Experiment

The effect on corn yield of interplanting two different cover crops, Trifolium repens, and Lolium perens into sweet corn, Zea mays, at 4 different times from corn planting was examined. Sweet corn was planted in 30 inch rows, and the cover crop was planted 0, 7, 14, and 21 days afterwards. The study was designed as a complete randomized block experiment with 4 replications. Weed management practices included pre-emergent herbicides and cultivation only treatments. No significant yield differences in corn yields were detected (alpha=.05). Most of the plots had very little weed competition, including those with no herbicide treatment. Earlier planted cover crops were better established at time of corn harvest. Additional work is needed to examine this practice in conditions of greater weed competion.

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Weed Management in Small Grains Harvested for Grain

EDIS ◽

10.32473/edis-wg009-2020 ◽

2020 ◽

Vol 2020 (3) ◽

Author(s):

Jason Ferrell ◽

Gregory MacDonald ◽

Pratap Devkota

Keyword(s):

Weed Control ◽

Weed Management ◽

Chemical Control ◽

Management Practices ◽

Good Management ◽

Small Grains ◽

Crop Competition

Successful weed control in small grains involves using good management practices in all phases of production. In Florida, winter weeds compete with small grains for moisture, nutrients, and light, with the greatest amount of competition occurring during the first six to eight weeks after planting. Weeds also cause harvest problems the following spring when the small grain is mature. This 4-page publication discusses crop competition, knowing your weeds, and chemical control. Written by J. A. Ferrell, G. E. MacDonald, and P. Devkota, and published by the UF/IFAS Agronomy Department, revised May 2020.

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Weed Management in Peanuts

EDIS ◽

10.32473/edis-wg008-2020 ◽

2020 ◽

Vol 2020 (3) ◽

Author(s):

Pratap Devkota

Keyword(s):

Weed Control ◽

Weed Management ◽

Management Practices ◽

Application Rate ◽

Good Management ◽

Peanut Production

Successful weed control in peanuts involves use of good management practices in all phases of peanut production. This 11-page document lists herbicide products registered for use in Florida peanut production, their mode of actions group, application rate per acre and per season, and reentry interval. It also discusses the performance of these herbicides on several weeds under Florida conditions. Written by J. A. Ferrell, G. E. MacDonald, and P. Devkota, and published by the UF/IFAS Agronomy Department, revised May 2020.

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Effect of Weed Management on the Parasitoid Community in Mediterranean Vineyards

Biology ◽

10.3390/biology10010007 ◽

2020 ◽

Vol 10 (1) ◽

pp. 7

Author(s):

Gabriella Möller ◽

Tamar Keasar ◽

Idan Shapira ◽

Daniella Möller ◽

Marco Ferrante ◽

...

Keyword(s):

Cover Crops ◽

Weed Management ◽

Soil Conservation ◽

Management Practices ◽

Ground Cover ◽

Parasitoid Species ◽

Parasitoid Community ◽

Growing Seasons ◽

Conservation Biocontrol ◽

Suction Sampling

Enriching agroecosystems with non-crop vegetation is a popular strategy for conservation biocontrol. In vineyards, the effects of specific seeded or planted cover crops on natural enemies are well-studied, whereas conserving spontaneously developing weeds received less attention. We compared parasitoid communities between matched pairs of vineyard plots in northern Israel, differing in weed management practices: “herbicide”, repeated herbicide applications vs. “ground cover”, maintaining resident weeds and trimming them when needed. Using suction sampling, we assessed the parasitoids’ abundance, richness, and composition during three grape-growing seasons. Ground cover plots had greater parasitoid abundances and cumulative species richness than herbicide-treated plots, possibly because of their higher vegetation cover and richness. Dominant parasitoid species varied in their magnitude and direction of response to weed management. Their responses seem to combine tracking of host distributions with attraction to additional vegetation-provided resources. Parasitoid community composition was mildly yet significantly influenced by weed management, while season, year, and habitat (weeds vs. vine) had stronger effects. Vineyard weeds thus support local biocontrol agents and provide additional previously demonstrated benefits (e.g., soil conservation, lower agrochemical exposure) but might also attract some crop pests. When the benefits outweigh this risk, weed conservation seems a promising step towards more sustainable agricultural management.

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