Brassicaceous Weed Seed Predation by Ground Beetles (Coleoptera: Carabidae)

Weed Science ◽  
2016 ◽  
Vol 64 (2) ◽  
pp. 294-302 ◽  
Author(s):  
Sharavari S. Kulkarni ◽  
Lloyd M. Dosdall ◽  
John R. Spence ◽  
Christian J. Willenborg
Keyword(s):  
Seed Predation ◽  
Weed Management ◽  
Physiological State ◽  
Seed Removal ◽  
Weed Seed ◽  
Weed Species ◽  
Wild Mustard ◽  
Activity Density ◽  
Field Pennycress ◽  
Species Activity

We used laboratory and field feeding trials to investigate adult carabid beetle preferences for three brassicaceous weed species (rapeseed, wild mustard, and field pennycress) that are pests in canola. All carabid species preferred seeds of rapeseed most and those of field pennycress least and showed intermediate preference for wild mustard seeds. Beetles highly preferred imbibed seeds of all three weed species. Activity–density of carabids and mean weed seed removal were highly correlated in field plots of canola, with activity–density accounting for 67% of the observed variation in seed removal. Our study indicates that seed consumption among carabids is influenced by several factors, including weed species, physiological state of seeds, and carabid activity–density. Carabid seed predation is significant in canola agroecosystems; therefore, understanding these influences has implications for ecological weed management.

Evaluating Seed Shatter of Economically Important Weed Species

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Nikki R. Burton ◽  
Hugh J. Beckie ◽  
Christian J. Willenborg ◽  
Steven J. Shirtliffe ◽  
Jeff J. Schoenau ◽  
...  
Keyword(s):  
Weed Management ◽  
Field Experiments ◽  
Management Strategies ◽  
Wild Oat ◽  
Population Abundance ◽  
Weed Seed ◽  
Weed Species ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Crop Maturity

The increasing occurrence of herbicide resistance, along with no new herbicide modes of action developed in over 30 yr, have increased the need for nonherbicidal weed management strategies and tactics. Harvest weed seed control (HWSC) practices have been successfully adopted in Australia to manage problematic weeds. For HWSC to be effective, a high proportion of weed seeds must be retained on the plant at crop maturity. This 2-yr (2014, 2015) study evaluated seed shatter of wild oat, green foxtail, wild mustard, and cleavers in both an early (field pea) and late (spring wheat) maturity crop in field experiments at Scott, Saskatchewan. Seed shatter was assessed using shatter trays collected once a week during crop ripening stage, as well as at two crop maturation or harvest stages (swathing, direct-combining). Seed shatter differed among weed species, but was similar between crops at maturity: ca. 30% for wild oat, 5% for cleavers, < 2% for wild mustard, and < 1% for green foxtail. Overall, seed shatter of wild oat occurred sooner and at greater levels during the growing season compared with the other weed species. Viability of both shattered and plant-retained seeds was relatively high for all species. The small amount of seed shatter of cleavers, wild mustard, and green foxtail suggests that these species may be suitable candidates for HWSC. Due to the amount and timing of wild oat seed shatter, HWSC may not reduce population abundance of this grassy weed.

scholarly journals Pest and weed seed predation in field defects within oilseed rape crops

2019 ◽  
Vol 2 ◽  
Author(s):  
Ezequiel González ◽  
Miroslav Seidl ◽  
Martin Štrobl ◽  
Tomáš Kadlec ◽  
Marco Ferrante ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Seed Predation ◽  
Weather Conditions ◽  
Ground Beetles ◽  
Agricultural Landscapes ◽  
Feeding Guilds ◽  
Weed Seed ◽  
Weed Species ◽  
Activity Density ◽  
Field Defects

Non-crop habitats can act as refuge for insects in agricultural landscapes and increase ecosystem services (ESs) in neighboring arable fields. Among the different types of non-crop habitats, field defects are temporary patches where sown plants are poorly developed and other plant species emerge. These defects can be common and large in years with extreme weather conditions. However, their relevance as habitat for beneficial insects and ESs provision is unknown. Here, we quantified two ESs (pest and weed seed predation) in field defects within oilseed rape crops and related ESs levels with the activity-density of ground beetles and temperature. In 10 fields, we used artificial caterpillars made of plasticine and seed cards of two weed species (Taraxacum sp. and Stellaria sp.) to quantify ESs in two sampling periods (spring and summer) and in three habitat types: field defects, standardly grown crop (field interiors) and crop-defect boundaries. Ground beetles were sampled using pitfall traps and classified into feeding guilds and body size classes. Insects and mammals were the main pest predators and predation increased in summer, but did not differ among habitats. Seed predation rates for both species were significantly higher in summer. Predation of Taraxacum seeds was higher at field interiors, whereas predation of Stellaria was significantly higher at field interiors and defects, compared to crop-defect boundaries. Insect predation increased with the activity-density of medium and large carnivorous carabids, whereas seed predation for both weed species was positively related to the activity-density of medium-sized herbivorous carabids. Finally, temperature was negatively linked to predation of artificial caterpillars and seeds of Taraxacum.

Variation in postdispersal weed seed predation in a crop field

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 148-155 ◽  
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.

scholarly journals Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

2020 ◽  
Vol 10 ◽  
pp. 1-14
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Management Practices ◽  
Soil Seed Bank ◽  
Shannon Index ◽  
Weed Seed ◽  
Weed Species ◽  
Western Kenya ◽  
Weed Diversity ◽  
Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

Comparison of weed communities in Manitoba ecoregions and crops

2000 ◽  
Vol 80 (4) ◽  
pp. 963-972 ◽  
Author(s):  
R. C. Van Acker ◽  
A. G. Thomas ◽  
J. Y. Leeson ◽  
S. Z. Knezevic ◽  
B. L. Frick
Keyword(s):  
Weed Management ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Canada Thistle ◽  
Wild Mustard ◽  
Polygonum Convolvulus ◽  
Weed Communities ◽  
Green Foxtail ◽  
Poaceae Family ◽  
Weed Survey

In 1997, a weed survey was conducted during July and August in fields of wheat, barley, oat, canola and flax in Manitoba. Field selection was based on a stratified-random sampling methodology using ecodistricts as strata. Species in the Poaceae family were most commonly observed in the survey, followed by species in the Polygonaceae, Asteraceae and Brassicaceae families. The six most abundant weed species were green foxtail [Setaria viridis (L.) Beauv.], wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), Canada thistle (Cirsium arvense L.), redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.). The survey highlighted significant differences between ecoregions and between crops in residual weed infestations. The weed community in the Boreal Transition ecoregion was dominated by seven species, whereas fields in the Aspen Parkland and Lake Manitoba Plain ecoregions were dominated by two species and the Interlake Plain ecoregion was dominated by only one species. Although significant differences were found between the weed communities in crops, they were not as great as differences between ecoregions. The Manitoba residual weed community in 1997 was very similar to that reported for 1978–1981 and 1986, suggesting that the same species should remain a focus for weed management. Key words: Weed survey, weed relative abundance, weed distributions, Manitoba ecoregions

scholarly journals Poecilus lucublandus (Coleoptera: Carabidae) and Pterostichus mutus Do Not Feed on Hair Fescue, Red Sorrel, and Poverty Oatgrass Seeds

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Alexandre M M C Loureiro ◽  
G Christopher Cutler ◽  
Vilis O Nams ◽  
Scott N White
Keyword(s):  
Seed Predation ◽  
Choice Test ◽  
Weed Seed ◽  
Weed Species ◽  
Vaccinium Angustifolium ◽  
Lowbush Blueberry ◽  
Rumex Acetosella ◽  
Weed Seeds ◽  
Poecilus Lucublandus ◽  
Danthonia Spicata

Abstract Poecilus lucublandus (Say), Pterostichus mutus (Say), and Harpalus rufipes (De Geer) are abundant Carabidae in lowbush blueberry fields and may contribute to weed seed predation. We used laboratory no-choice test experiments to determine if these beetles feed on seeds of hair fescue (Festuca filiformis Pourr., Poales: Poaceae), poverty oatgrass (Danthonia spicata L.), and red sorrel (Rumex acetosella L., Caryophyllales: Polygonaceae), which are common weeds in lowbush blueberry (Vaccinium angustifolium Ait., Ericales: Ericaceae) fields. Poecilus lucublandus and P. mutus did not feed on seeds of the test weed species, but H. rufipes consumed on average over 30 seeds of each species. There are other weed seeds in blueberry fields that could be palatable to P. lucublandus and P. mutus, which warrants further research on the granivory potential of these important carabid species.

Tolpyralate Efficacy: Part 1. Biologically Effective Dose of Tolpyralate for Control of Annual Grass and Broadleaf Weeds in Corn

2018 ◽  
Vol 32 (6) ◽  
pp. 698-706 ◽  
Author(s):  
Brendan A. Metzger ◽  
Nader Soltani ◽  
Alan J. Raeder ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Effective Dose ◽  
Weed Management ◽  
Field Studies ◽  
Biologically Effective Dose ◽  
Limited Information ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Low Field ◽  
Green Foxtail

AbstractTolpyralate is a new 4-hydroxyphenyl-pyruvate dioxygenase (HPPD)-inhibiting herbicide for POST weed management in corn; however, there is limited information regarding its efficacy. Six field studies were conducted in Ontario, Canada, over 3 yr (2015 to 2017) to determine the biologically effective dose of tolpyralate for the control of eight annual weed species. Tolpyralate was applied POST at six doses from 3.75 to 120 g ai ha−1and tank mixed at a 1:33.3 ratio with atrazine at six doses from 125 to 4,000 g ha−1. Regression analysis was performed to determine the effective dose (ED) of tolpyralate, and tolpyralate+atrazine, required to achieve 50%, 80%, or 90% control of eight weed species at 1, 2, 4, and 8 wk after application (WAA). The ED of tolpyralate for 90% control (ED90) of velvetleaf, common lambsquarters, common ragweed, redroot pigweed or Powell amaranth, and green foxtail at 8 WAA was ≤15.5 g ha−1; however, tolpyralate alone did not provide 90% control of wild mustard, barnyardgrass, or ladysthumb at 8 WAA at any dose evaluated in this study. In contrast, the ED90for all species in this study with tolpyralate+atrazine was ≤13.1+436 g ha−1, indicating that tolpyralate+atrazine can be highly efficacious at low field doses.

Effects of Initial Seed-Bank Density on Weed Seedling Emergence during the Transition to an Organic Feed-Grain Crop Rotation

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Richard G. Smith ◽  
Randa Jabbour ◽  
Andrew G. Hulting ◽  
Mary E. Barbercheck ◽  
David A. Mortensen
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Cover Crop ◽  
Management Practices ◽  
Transition Period ◽  
Red Clover ◽  
Weed Seed ◽  
Weed Species ◽  
Organic Certification ◽  
Weed Seeds

The transition period to certified organic production can present a significant weed management challenge for growers. Organic certification requires that prohibited fertilizers and pesticides must not have been used for 36 mo before harvest of the first organic crop. Understanding how organic management practices and initial weed seed-bank densities affect weed population dynamics during the transition period may improve weed management efficacy and adoption of organic practices. We examined how tillage systems (full or reduced) and cover crop species planted during the first transition year (rye or a mixture of timothy and red clover) affect the seedling densities of three common annual weed species, common lambsquarters, velvetleaf, and foxtail spp., during the 3-yr transition period. Weed seeds were applied in a one-time pulse at the beginning of the study at three densities, low, medium, and high (60, 460, and 2,100 seeds m−2, respectively), and cumulative seedling densities of each species were assessed annually. Treatment factors had variable and species-specific effects on weed seedling densities. In general, the full-tillage system, with an initial cover crop of timothy and red clover, resulted in the lowest density of weed seedlings following seed-bank augmentation. There was little consistent association between the initial densities of applied weed seeds in the weed seed bank at the start of the transition and weed seedling densities at the end of the transition period. This suggests that when multiple crop and weed cultural management practices are employed during the organic transition period, initial failures in weed management may not necessarily lead to persistent and intractable annual weed species management problems following organic certification.

Annual Postdispersal Weed Seed Predation in Contrasting Field Environments

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Adam S. Davis ◽  
Erin C. Taylor ◽  
Erin R. Haramoto ◽  
Karen A. Renner
Keyword(s):  
Seed Predation ◽  
Best Management Practices ◽  
Weed Management ◽  
Wheat Crop ◽  
Weed Seed ◽  
Giant Foxtail ◽  
Giant Ragweed ◽  
Ecological Weed Management ◽  
The Impact ◽  
Predation Rates

Interest in weed seed predation as an ecological weed management tactic has led to a growing number of investigations of agronomic and environmental effects on predation rates. Whereas the measurements in most of these studies have taken place at very short timescales, from days to weeks, measurements at longer timescales (from several months to a year) have greater relevance to the demographic impact of weed seed predation and potential contributions from this process to ecological weed management. Our aim was to quantify the impact of crop phase, within a corn–soybean–wheat crop sequence, on quarterly and annual seed predation rates of giant foxtail, giant ragweed, and velvetleaf. The study took place in areas of the northern U.S. Corn Belt contrasting in dominant land use: Savoy, IL (2005–2007), where corn and soybean production predominates, and East Lansing, MI (2005–2008), where crop production occurs within an old field/forest landscape matrix. Mean annual rates of weed seed predation by the combined action of invertebrate and vertebrate predators were 31 ± 1.6% for giant ragweed, 37 ± 1.4% for velvetleaf, and 53 ± 1.4% for giant foxtail. Crop phase had negligible effects upon long-term seed predation rates, accounting for less than 2% of observed variation. Weed species and site-year, in contrast, contributed 35% and 40%, respectively, of the variation in cumulative annual seed predation. These results are consistent with the spatial variability in best management practices seen at spatial scales greater than the county level: weed seed predation appears to be an inherently site-specific phenomenon. New developments in managing weed seed predation as an ecosystem service are therefore likely to have local recommendation domains or to be driven by stochastic annual variation related to weather or granivore demography.

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