scholarly journals Winter Weed Emergence during Carinata (Brassica carinata) Production

EDIS ◽  
2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ruby Tiwari ◽  
Pratap Devkota ◽  
Michael J. Mulvaney
Keyword(s):  
Brassica Carinata ◽  
Weed Species ◽  
Weed Emergence

This publication provides information for predicting emergence timing of common winter weed species for carinata production. Written by Ruby Tiwari, Pratap Devkota, and Michael J. Mulvaney, and published by the UF/IFAS Agronomy Department, June 2021.

Emergence Patterns of Winter and Summer Annual Weeds in Ethiopian mustard (Brassica carinata) Cropping System

Weed Science ◽  
2021 ◽  
pp. 1-33
Author(s):  
Ruby Tiwari ◽  
Theresa A. Reinhardt Piskackova ◽  
Pratap Devkota ◽  
Michael J. Mulvaney ◽  
Jason A. Ferrell ◽  
...  
Keyword(s):  
Growing Season ◽  
Frost Damage ◽  
Brassica Carinata ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Weed Species ◽  
Ethiopian Mustard ◽  
Emergence Patterns ◽  
The Impact ◽  
Weed Emergence

Abstract Ethiopian mustard (Brassica carinata A. Braun) is a biofuel crop that was recently introduced in the southeastern United States. In order for this crop to be successful, there is a need to develop integrated weed management strategies that complement its rotation with summer cash crops. The objectives of this research were to evaluate the effect of previous season summer crops on winter weed emergence patterns during Ethiopian mustard growing season and to assess the impact of planting Ethiopian mustard on the emergence patterns of summer weed species. Gompertz models were fit to winter and summer weed emergence patterns. All models represented more than 80% of the variation with RMSE values less than 0.20. The emergence pattern for winter weed species was best described using Growing Degree Days (GDD) accumulation, and this model can be utilized for implementing weed control strategies at the critical Ethiopian mustard growth stages. The results also showed that summer weeds can emerge during the winter in northern Florida but do not survive frost damage, which might create off-season seed bank reductions before the summer crop growing season.

Establishing white clover (Trifolium repens) as a living mulch: weed control and herbicide tolerance

2021 ◽  
pp. 1-28
Author(s):  
Nicholas T. Basinger ◽  
Nicholas S. Hill
Keyword(s):  
Weed Control ◽  
White Clover ◽  
Cover Crops ◽  
Herbicide Tolerance ◽  
Single Application ◽  
Weed Species ◽  
Living Mulch ◽  
Herbicide Resistant ◽  
Research And Education ◽  
Weed Emergence

Abstract With the increasing focus on herbicide-resistant weeds and the lack of introduction of new modes of action, many producers have turned to annual cover crops as a tool for reducing weed populations. Recent studies have suggested that perennial cover crops such as white clover could be used as living mulch. However, white clover is slow to establish and is susceptible to competition from winter weeds. Therefore, the objective of this study was to determine clover tolerance and weed control in established stands of white clover to several herbicides. Studies were conducted in the fall and winter of 2018 to 2019 and 2019 to 2020 at the J. Phil Campbell Research and Education Center in Watkinsville, GA, and the Southeast Georgia Research and Education Center in Midville, GA. POST applications of imazethapyr, bentazon, or flumetsulam at low and high rates, or in combination with 2,4-D and 2,4-DB, were applied when clover reached 2 to 3 trifoliate stage. Six weeks after the initial POST application, a sequential application of bentazon and flumetsulam individually, and combinations of 2,4-D, 2,4-DB, and flumetsulam were applied over designated plots. Clover biomass was similar across all treatments except where it was reduced by sequential applications of 2,4-D + 2,4-DB + flumetsulam in the 2019 to 2020 season indicating that most treatments were safe for use on establishing living mulch clover. A single application of flumetsulam at the low rate or a single application of 2,4-D + 2,4-DB provided the greatest control of all weed species while minimizing clover injury when compared to the non-treated check. These herbicide options allow for control of problematic winter weeds during clover establishment, maximizing clover biomass and limiting canopy gaps that would allow for summer weed emergence.

Interference between pigweed (Amaranthusspp.), barnyardgrass(Echinochloa crus-galli), and soybean (Glycine max)

Weed Science ◽  
1998 ◽  
Vol 46 (5) ◽  
pp. 533-539 ◽  
Author(s):  
Paul Cowan ◽  
Susan E. Weaver ◽  
Clarence J. Swanton
Keyword(s):  
Competitive Ability ◽  
Field Experiments ◽  
Yield Loss ◽  
Seedling Emergence ◽  
Growth Time ◽  
Weed Species ◽  
Soybean Yield ◽  
Competitive Index ◽  
Loss Maximum ◽  
Weed Emergence

Field experiments were conducted to determine the influence of time of emergence and density of single and multispecies populations of pigweed and barnyardgrass on soybean yield and competitive abilities of pigweed and barnyardgrass. Pigweed and barnyardgrass were established at selected densities within 12.5 cm on either side of the soybean row. Pigweed and barnyardgrass seeds were sown concurrently with soybean and at the cotyledon stage of soybean growth. Time and density of pigweed and barnyardgrass seedling emergence relative to soybean influenced the magnitude of soybean yield loss. Maximum soybean yield loss ranged from 32 to 99%, depending upon time of emergence relative to soybean. Pigweed was more competitive than barnyardgrass across all locations, years, and time of weed emergence. When pigweed was assigned a competitive index of 1 on a scale from 0 to 1, the competitive ability of barnyardgrass ranged from 0.075 to 0.40 of pigweed, depending upon location and time of emergence. This is the first multiple weed species study to include time of weed emergence relative to the crop. Competitive index values for multiple weed species must be calculated from field experiments in which weeds are grown with the crop under differing environmental conditions.

scholarly journals REVIEW OF THE INFLUENCE OF CROP ROTATION AND PRIMARY TILLAGE OPERATIONS ON WEED SEED BANK

2021 ◽  
Vol 9 (7) ◽  
pp. 407-421
Author(s):  
Nawal Al-Hajaj
Keyword(s):  
Seed Production ◽  
Crop Rotation ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Crop Productivity ◽  
Crop Rotations ◽  
Weed Seed ◽  
Weed Species ◽  
Primary Tillage ◽  
Weed Emergence

In this study, we reviewed weed seed bank dynamic and main agriculture operations to come up with the weed seed management modeling designed to increase crop productivity by removing weed competition. Weed contributing with 10% loss of total global grain production. Weed seed bank regulate by five demographic processes seedling recruitment and survival, seed production, dispersal and seed survival in soil. The main agriculture operations that interference with weed seed bank are crop rotation and primary tillage. Tillage systems affect weed emergence, management, and seed production; therefore, changing tillage practices changes the composition, vertical distribution, and density of weed seed bank in agricultural soils. Weed species vary in their response to various crop rotations, due to the variability of weed-crop competition in their relative capacity to capture growth–limiting resources. Crop rotations affect weed emergence, management, composition, and density of weed seed bank. Finally, the study suggests elevating crop competitiveness against weeds, through a combination of crop rotation and reduce_ zero tillage, has strong potential to reduce weed-induced yield losses in crop.

Glyphosate and Paraquat Effects on Weed Seed Germination and Seedling Emergence

Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 249-251 ◽  
Author(s):  
G. H. Egley ◽  
R. D. Williams
Keyword(s):  
Seedling Emergence ◽  
Soil Surface ◽  
Amaranthus Retroflexus ◽  
Sorghum Halepense ◽  
Weed Species ◽  
Sida Spinosa ◽  
Broadleaf Species ◽  
Prickly Sida ◽  
Grass Weed ◽  
Weed Emergence

Glyphosate [N-(phosphonomethyl)glycine] (30, 125, 250 mg/L) in petri dishes had no effect on germination of prickly sida(Sida spinosaL.), velvetleaf(Abutilon theophrastiMedic), barnyardgrass [Echinocloa crus-galli(L.) Beauv.] and johnsongrass [Sorghum halepense(L.) Pers.] seeds, but additional experimentation indicated that glyphosate stimulated germination of redroot pigweed(Amaranthus retroflexusL.) seeds. Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) (30, 125, 250 mg/L) did not affect germination of the three broadleaf species, but inhibited johnsongrass and barnyardgrass germination. In the greenhouse, soil surface applications of glyphosate (1.1, 2.2, 9.0 kg/ha) did not significantly affect emergence of these five weed species when they were on or beneath the soil surface at time of treatment. Paraquat (same rates) did not affect broadleaf weed emergence but some rates inhibited grass weed emergence when the seeds were treated while on the soil surface. It is unlikely that normal field use rates of glyphosate will influence weed emergence; whereas paraquat may inhibit the emergence of some grass weeds if the herbicide contacts seeds on the soil surface.

Predicting weed emergence for eight annual species in the northeastern United States

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 913-919 ◽  
Author(s):  
Matthew W. Myers ◽  
William S. Curran ◽  
Mark J. VanGessel ◽  
Dennis D. Calvin ◽  
David A. Mortensen ◽  
...  
Keyword(s):  
Model Verification ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Giant Foxtail ◽  
Smooth Pigweed ◽  
Weed Emergence ◽  
Large Crabgrass

A 2-yr experiment assessed the potential for using soil degree days (DD) to predict cumulative weed emergence. Emerged weeds, by species, were monitored every 2 wk in undisturbed plots. Soil DD were calculated at each location using a base temperature of 9 C. Weed emergence was fit with logistic regression for common ragweed, common lambsquarters, velvetleaf, giant foxtail, yellow foxtail, large crabgrass, smooth pigweed, and eastern black nightshade. Coefficients of determination for the logistic models fit to the field data ranged between 0.90 and 0.95 for the eight weed species. Common ragweed and common lambsquarters were among the earliest species to emerge, reaching 10% emergence before 150 DD. Velvetleaf, giant foxtail, and yellow foxtail were next, completing 10% emergence by 180 DD. The last weeds to emerge were large crabgrass, smooth pigweed, and eastern black nightshade, which emerged after 280 DD. The developed models were verified by predicting cumulative weed emergence in adjacent plots. The coefficients of determination for the model verification plots ranged from 0.66 to 0.99 and averaged 0.90 across all eight weed species. These results suggest that soil DD are good predictors for weed emergence. Forecasting weed emergence will help growers make better crop and weed management decisions.

scholarly journals If phenolic compounds in the soil with buckwheat residues affect the emergence and growth of weed seedlings?

2020 ◽  
Vol 42 (9) ◽  
Author(s):  
Magdalena Szwed ◽  
Joanna Mitrus ◽  
Wiesław Wiczkowski ◽  
Henryk Dębski ◽  
Marcin Horbowicz
Keyword(s):  
Phenolic Compounds ◽  
Inhibitory Effect ◽  
Plant Residues ◽  
Wild Oat ◽  
Weed Species ◽  
Cultivation Conditions ◽  
Barnyard Grass ◽  
Galium Aparine ◽  
Strong Inhibitory Effect ◽  
Weed Emergence

Abstract This study was conducted to determine if common buckwheat (Fagopyrum esculentum Moench) residues affect a phenolics composition in soil, and are effective for limiting emergence, growth and metabolic changes in barnyard grass (Echinochloa crus-galli (L.) P. Beauv.), wild oat (Avena fatua L.), yellow foxtail (Setaria pumila Schult.), silky windgrass (Apera spica-venti L.), catchweed bedstraw (Galium aparine L.), scentless mayweed (Matricaria inodora L.), and tiny vetch (Vicia hirsuta L.). In the study, the residues of 14-day-old buckwheat plants were used (cv. Hruszowska). After removal of the above-ground parts, the buckwheat root residues (BRR) remained in the soil for an additional 7 days before the weeds were sown. For comparison, under the same cultivation conditions, the effect of entire buckwheat plant residues (BPR) in soil was assessed. BPR and BRR in the soil caused a decrease in the emergence of all weed species except the tiny vetch. The growth of barnyard grass, wild oat, yellow foxtail, catchweed bedstraw, and scentless mayweed was inhibited by BRR, but not BPR. BRR had a particularly strong inhibitory effect on the growth of scentless mayweed (SM) and catchweed bedstraw (CB). Thirty-day-old SM and CB control plants were about 4 and 3.5 times higher, respectively, than plants growing in the presence of BRR. Furthermore, chlorophyll and carotenoid contents in the barnyard grass and catchweed bedstraw were more prominently reduced by BRR than BPR. Stressful conditions caused by buckwheat residues in the soil increased the level of phenolic compounds in the tissues of weeds examined. Soil with buckwheat residues contained a low level of phenolic compounds, which may indicate their slow release from the residue or rapid utilisation by microorganisms. These phenolic compounds probably cannot be directly responsible for allelopathic inhibition of weed emergence and growth.

Seed and microsite limitations to emergence of four annual weed species

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 571-577 ◽  
Author(s):  
Nathan Boyd ◽  
Rene Van Acker
Keyword(s):  
Soil Compaction ◽  
Management Practices ◽  
Seed Density ◽  
Wild Oat ◽  
Annual Species ◽  
Weed Species ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Weed Emergence ◽  
Number Of Seeds

The emergence of annual species depends on the number of seeds present and the biotic and abiotic conditions directly surrounding those seeds (the microsite). A field experiment was conducted to study the relative importance of seed presence vs. microsite conditions in determining the emergence of four annual species. Green foxtail, wild mustard, wild oat, and canola were seeded at 200, 400, and 1,200 seeds m−2in separate plots in a coarse, loamy, mixed Typic Haplocryoll and a fine, mixed Typic Haplocryoll soil. Five microsite modification treatments (control, irrigation, soil compaction, soil compaction plus irrigation, and no crop) were applied to all weed seed density treatments for each weed species. All plots were seeded to spring wheat. Irrigation or soil compaction increased percent emergence of wild oat. Green foxtail emergence tended to increase with soil compaction in 2001 but not in 2002. Wild mustard and canola emergence were largely unaffected by microsite modification treatments. Weed emergence increased with increasing seed density for all species, but the proportion of the total number of seeds emerging decreased with increasing seed density for all species. We suggest that the emergence of the four weed species in this experiment was both seed and microsite limited. Increasing the number of seeds in the soil increased the probability of seeds landing within an appropriate microsite. For these four species, therefore, weed spread and weed patch formation may be determined both by seed production and dispersal and by variability in soil microsite conditions. Results suggest that weed management practices should limit seed dispersal of all species and discourage weed emergence of hard-to-control species during critical establishment periods.

Tillage index predicts weed seedling recruitment depth

2004 ◽  
Vol 84 (1) ◽  
pp. 319-326 ◽  
Author(s):  
R. C. Van Acker ◽  
W. J. Bullied ◽  
M. J. du Croix Sissons
Keyword(s):  
Weed Management ◽  
Seedling Recruitment ◽  
Soil Surface ◽  
Conventional Tillage ◽  
Strategy Development ◽  
Weed Species ◽  
Relative Level ◽  
Green Foxtail ◽  
Simple Estimation ◽  
Weed Emergence

The influence of tillage on the depth of weed seedling recruitment has implications for species competitive ability, weed management strategy development, and the modeling of weed emergence; characterization of this relationship could aid in the creation of field-specific models of weed seedling recruitment. A tillage index based on the percentage of residue cover remaining on the soil surface after tillage events was assessed for 44 zero-tillage and 44 conventional-tillage fields across Manitoba, Canada. This index was related to in situ measurements of seedling recruitment depth from the same fields for five annual weed species. The modeled relationship was linear and unique for each species (R2 values ranged from 0.38 to 0.71). The relationship did not differ between pre- and post-seeding measurements, or between years, except for green foxtail. Slopes of the regression lines were greater for species such as volunteer wheat, which can recruit from a great range of depths. The results of this study show that recent tillage strongly influences mean weed seedling recruitment depth, and that the recruitment depth of summer annual weed seedlings is related in a continuous and reliable manner to a simple estimation of the relative level of tillage (including seeding) applied in one season. Key words: Recruitment depth, tillage index, weed emergence, weed seedlings

Evaluation of Weed Emergence Model AlertInf for Maize in Soybean

Weed Science ◽  
2014 ◽  
Vol 62 (2) ◽  
pp. 360-369 ◽  
Author(s):  
Roberta Masin ◽  
Donato Loddo ◽  
Valentina Gasparini ◽  
Stefan Otto ◽  
Giuseppe Zanin
Keyword(s):  
High Efficiency ◽  
Cultural Practices ◽  
Efficiency Index ◽  
Point Of View ◽  
Weed Species ◽  
Common Lambsquarters ◽  
The Third ◽  
Northeastern Italy ◽  
Further Development ◽  
Weed Emergence

AlertInf is a recently developed model to predict the daily emergence of three important weed species in maize cropped in northern Italy (common lambsquarters, johnsongrass, and velvetleaf). Its use can improve the effectiveness and sustainability of weed control, and there has been growing interest from farmers and advisors. However, there are two important limits to its use: the low number of weed species included and its applicability only to maize. Consequently, the aim of this study was to expand the AlertInf weed list and extend its use to soybean. The first objective was to add another two important weed species for spring-summer crops in Italy, barnyardgrass and large crabgrass. Given that maize and soybean have different canopy architectures that can influence the interrow microclimate, the second objective was to compare weed emergence in maize and soybean sown on the same date. The third objective was to evaluate if AlertInf was transferable to soybean without recalibration, thus saving time and money. Results showed that predictions made by AlertInf for all five species simulated in soybean were satisfactory, as shown by the high efficiency index (EF) values, and acceptable from a practical point of view. The fact that the algorithm used for estimating weed emergence in maize was also efficient for soybean, at least for crops grown in northeastern Italy with standard cultural practices, encourages further development of AlertInf and the spread of its use.

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