Herbicide Rate Effects on Weed and Root Maggot Dynamics in Canola

Weed Science ◽  
2008 ◽  
Vol 56 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Jim S. Broatch ◽  
Lloyd M. Dosdall ◽  
John T. O'Donovan ◽  
K Neil Harker ◽  
George W. Clayton

Weed management strategies can influence insect infestations in field crops, yet no attempts have been made previously to manipulate weed populations in canola for integrated weed and insect management. Field studies were conducted during 2003 to 2005 at Lacombe and Beaverlodge, Alberta, Canada to manipulate weed and root maggot, Delia spp. (Diptera: Anthomyiidae), interactions in canola. Densities of monocot weeds were varied by altering herbicide applications, with rates ranging from 0 to 100% of the rate recommended. Weed populations declined, and yields were variable with increased herbicide rates. Root maggot damage decreased with increases in monocot weed dry weight for both canola species at both study sites. Results support the hypothesis that heterogenous environments, arising from mixed populations of monocot weeds with canola, minimize opportunities for females of Delia spp. to complete the behavioral sequence required for oviposition, leading to reduced infestation levels in weedy systems. However, effects of dicot weeds on root maggot infestations varied between sites as a result of site-related differences in weed species complexes. When wild mustard was common, crop damage increased, because this weed can serve as an alternate host for root maggots. The study emphasizes the importance of adopting crop management practices that are compatible for both weed and root maggot control.

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandra M. Knight ◽  
Wesley J. Everman ◽  
David L. Jordan ◽  
Ronnie W. Heiniger ◽  
T. Jot Smyth

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.


2020 ◽  
Author(s):  
Akashdeep Singh ◽  
S. S. Rana ◽  
Anju Bala

Chickpea (Cicer arietinum) is one of the most important pulse crops but it’s productivity in India is quite low. There are various reasons for low productivity. Weed control is the basic requirement and the major component of crop management. Weeds on an average reduce the crop yield by 40-87 per cent. Deciding time to control weeds requires detailed knowledge of the weed populations in the field. Different management practices like altering spacing, competitive cultivars, etc. can help in enhancing the productivity. With the world entering the precision-farming era, more emphasis is being put on the use of post-emergence herbicides. Application of two or more herbicide at the same time or as a double knockdown and integrating with hand-weeding provides desirable control of different weed species besides reducing the hazard of chemical weed control.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Bhupesh Kumar Mishra ◽  
Santosh Pandey

The different weed control methods (two hand weeding at 25 and 45 days after sowing (DAS) and one hand weeding at 25 DAS along with unweeded control ), organic sources of nitrogen (vermicompost, poultry manure, city manure and FYM) and their interaction were compared for their efficiency on various weed species and yield of wheat. Two hand weeding (W2) gave significantly maximum weed control. This was followed by one hand weeding at 25 DAS and control. These weed control methods significantly enhanced the yield and yield components of wheat. Among organic sources of nitrogen vermicompost (M1) recorded minimum weed density, weed dry weight and maximum yield, followed by poultry manure, city manure and FYM.


2018 ◽  
Vol 5 (01) ◽  
Author(s):  
MUKESH KUMAR ◽  
A. K. GHORAI ◽  
USSREE K. NANDY ◽  
S MITRA K. GHORAI ◽  
D. K. KUNDU

A field experiment was conducted to find out suitable weed management practice for control of broad spectrum weeds in jute during 2015 and 2016. Seven weed management practices viz., T : 1 Farmers practices , T : Stale seed bed (SSB) + glyphosate 41% SL 1.25 kg/ha, T : SSB+glyphosate 1.75 2 3 kg/ha, T : SSB + glyphosate 1.25 kg/ha + pretilachlor 50% EC 1.0 kg/ha, T : SSB +glyphosate 4 5 1.75kg/ha + pretilachlor 1.0 kg/ha, T : SSB +glyphosate 1.25 kg/ha+butachlor 50 % EC 1.0 kg/ha and 6 T : SSB + glyphosate 1.75 kg/ha + butachlor1.0 kg/ha were tested in randomised block design (RBD) 7 with three replication. Cyperus rotundus was dominant weed species with 60-75 % of relative density in experimental field. SSB + glyphosate 1.75 kg/ha + pretilachlor 1.0 kg/ha effectively controlled density and dry weight of Cyperus rotundus, grass weeds (Echinochloa colonum and Eleusine indica), broad leaved weeds (Physalis minima, and Trianthema portulacastrum) compared to farmers' practices. SSB + glyphosate 1.75 kg/ha + pretilachlor 1.0 kg/ha also recorded the highest plant height (293 cm and 335 cm), basal diameter (2.14 and 2.19 cm) and fibre yield (34.9 and 38.9 q/ha) of jute during 2015 and 2016. This treatment also recorded the highest net income (Rs 54182 and 75687/ha) and benefit-cost ratio (1.23 and 1.46) in jute cultivation during 2015 and 2016, Therefore, SSB with glyphosate 1.75 kg/ha +pretilachlor 1.0 kg/ha may be practiced for effective weeds control specially Cyperus rotundus, higher productivity and income in jute cultivation.


2020 ◽  
pp. 1-11
Author(s):  
Maxwel C. Oliveira ◽  
Anelise Lencina ◽  
André R. Ulguim ◽  
Rodrigo Werle

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.


2019 ◽  
Vol 17 (3) ◽  
pp. 265-273
Author(s):  
Rakia Afroz ◽  
Md. Abdus Salam ◽  
Mahfuza Begum

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from December 2016 to May 2017 to investigate the effect of weeding regime on the performance of boro rice cultivars. The experiment comprised of two factors, Factor A-  Rice cultivars: BRRI dhan28, BRRI dhan29, and BRRI dhan74, Factor B: Methods of weeding- no weeding, two hand weedings at 15 and 35 DATs, application of pre-emergence herbicide Commit, application of early post-emergence herbicide Pediplus, application of pre-emergence herbicide Commit followed by application of early post-emergence herbicide Pediplus, application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT, and application of early post-emergence herbicide Pediplus followed by one hand weeding at 35 DAT. The experiment was laid out in a split plot design assigning rice cultivars in the main plots and weed management practices in the sub-plots with three replications. Fourteen weed species infested the experimental field belonging to six families. Among the weed species, four were grasses, four were broad leaves and six were sedges. Cultivar exerted significant effect on weed density and dry weight. Both the highest weed density and dry weight were found in BRRI dhan28 and the lowest ones were observed in BRRI dhan29 rice cultivar. Weed density and weed dry weight were significantly influenced by weeding regime. The highest weed density and dry weight were observed in no weeding condition and application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT showed the best performance. BRRI dhan29 produced the highest grain and straw yields among the cultivars. Weed control had pronounced influence on yield of rice. The highest grain yield was obtained in application of pre-emergence herbicide Pretilachlor (Commit)followed by one hand weeding at 35 DAT and the lowest one was obtained in control (no weeding) treatment. From the results of the study it may be concluded that rice cultivar BRRI dhan29 with application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT might be the best treatment for controlling weed effectively as well as obtaining highest yield and highest economic return. J Bangladesh Agril Univ 17(3): 265–273, 2019


Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 507-514 ◽  
Author(s):  
David H. Gent ◽  
Jillian M. Lang ◽  
Michael E. Bartolo ◽  
Howard F. Schwartz

Xanthomonas leaf blight, caused by the bacterium Xanthomonas axonopodis pv. allii, is an emerging disease of onion in the western United States and worldwide, but few management strategies have been developed because little is known about disease epidemiology and pathogen survival. Therefore, we sought to identify and quantify primary inoculum sources of the pathogen in Colorado. Growth chamber and field studies evaluated survival and dissemination of X. axonopodis pv. allii in association with weed, alternate host, and volunteer onion plants, irrigation water, and crop debris. Epiphytic X. axonopodis pv. allii was recovered from the foliage of nine asymptomatic weed species and Medicago sativa, but the bacterium was not recovered from plants in locations where an epidemic of Xanthomonas leaf blight did not occur the prior year. The bacterium also was isolated from volunteer onion with characteristic Xanthomonas leaf blight symptoms. A rifampicin mutant of X. axonopodis pv. allii strain O177 was recovered consistently from the irrigation tail water of onion fields inoculated with the bacterium; populations as large as 3.02 × 104 CFU/ml were recovered. X. axonopodis pv. allii was recovered from infested onion leaves 9 months after they were placed on the soil surface or buried to a depth of 25 cm, but culturable populations of the pathogen decreased 104 to 106 more in buried leaves. Cultural practices that avoid or eliminate X. axonopodis pv. allii inoculum sources should reduce Xanthomonas leaf blight losses to onion.


2013 ◽  
Vol 27 (4) ◽  
pp. 798-802 ◽  
Author(s):  
RaeLynn A. Butler ◽  
Sylvie M. Brouder ◽  
William G. Johnson ◽  
Kevin D. Gibson

Greenhouse experiments were conducted in 2011 to evaluate the effect of mowing frequency and mowing height on four summer annual weed species (large crabgrass, barnyardgrass, giant ragweed, and common lambsquarters). Plants were clipped at three heights (5, 10, or 20 cm) and at two frequencies (single clipping or repeated clippings at the same height) to simulate mowing. A nonclipped control was also grown for each species. When clipped once, large crabgrass, barnyardgrass, and giant ragweed produced at least 90% of the total dry weight (DW) of the nonclipped plants, and common lambsquarters produced at least 75%. A single cut was generally not sufficient to prevent weed seed production or kill any of the weeds in this study. Repeated clipping reduced large crabgrass, giant ragweed, and common lambsquarters reproductive DW to 46, 27, and 10% respectively, of the nonclipped control. Barnyardgrass plants that were repeatedly clipped produced between 0 and 8% of the seed DW of nonclipped plants, depending on clipping height. Repeated clipping reduced weed total DW to below 40% for all species compared to nonclipped plants. Our results suggest that, unless combined with other weed management practices, repeated mowing may be necessary to limit the growth and seed production of these weed species.


2021 ◽  
Vol 3 ◽  
Author(s):  
Katie M. Patterson ◽  
Lauren M. Schwartz-Lazaro ◽  
Gabrielle LaBiche ◽  
Daniel O. Stephenson

The soil seedbank allows for long-term persistence of weed species in agricultural fields. Some weed species can persist in the soil seedbank for extended periods. Restricting inputs into the weed seedbank has a large impact on future population density and influences management practices of these weeds in soybean production systems. Harvest weed seed control (HWSC) tactics incorporate mechanical and cultural management strategies to target weed seeds present at harvest. A 3-year trial was initiated to determine if continual use of the HWSC method, narrow windrow burning, selects for earlier seed set and shattering in Louisiana soybean. No shifts in weed populations or shattering time were observed. However, there was a significant reduction in weed density and the weed seed present in the soil seedbank when HWSC and robust herbicide programs were used in combination. Therefore, utilizing multiple effective weed management strategies is imperative in reducing the soil seedbank.


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>


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