THE BIOLOGY OF CANADIAN WEEDS.: 46. Silene noctiflora L.

1980 ◽  
Vol 60 (4) ◽  
pp. 1243-1253 ◽  
Author(s):  
J. McNEILL
Keyword(s):  
North America ◽  
Weed Species ◽  
Leguminous Crops ◽  
Agricultural Areas

A review is provided of information on the biology of Silene noctiflora (Melandrium noctiflorum), night-flowering catchfly, an annual weed species introduced into North America from Eurasia. An important weed, particularly of grain and leguminous crops, S. noctiflora occurs across the agricultural areas of Canada, although less common in the Atlantic provinces. It is resistant to common herbicides such as 2,4-D, 2,4,5-T, MCPA and mecoprop.

Murdannia nudiflora (doveweed).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
South East Asia ◽  
Agricultural Crops ◽  
Soil Drainage ◽  
Weed Species ◽  
Invasive Weed ◽  
Land Preparation ◽  
Agricultural Areas ◽  
Murdannia Nudiflora ◽  
Near Future ◽  
Specialist Group

Abstract M. nudiflora is classified as one of the world's worst weeds by Holm et al. (1977), infesting no less than 16 crops in 23 countries. It is a major weed species in rice and other crops (Moody, 1989), and is a moderately invasive weed species both in agricultural crops and non-agricultural areas in South and South-east Asia (Waterhouse, 1993). Its special ability to root easily at the nodes, propagating clonally through cut stems and dispersal during tillage and land preparation make this weed difficult to control. This trait coupled with its ability to adapt and survive a wide ecological window of soil types, pH, moisture availability and soil drainage makes M. nudiflora a weed to watch for potential spread into new areas in near future, and a species under the 'alert list' by the Invasive Species Specialist Group. Oliveira Pellegrini et al. (2016) recognize M. nudiflora as one of two Murdannia species invasive in the Neotropics.

Impact of Alien Plants on Grant Basin Rangelands

1996 ◽  
Vol 10 (2) ◽  
pp. 384-391 ◽  
Author(s):  
James A. Young ◽  
William S. Longland
Keyword(s):  
North America ◽  
Great Basin ◽  
Alien Plants ◽  
Western North America ◽  
Biological Functions ◽  
Annual Species ◽  
Weed Species ◽  
Model Ecosystem ◽  
Alien Weed ◽  
The Impact

Our purpose is to discuss the impact of alien plants on rangeland ecosystems of the Great Basin in terms of their effects on biological functions. The sagebrush/bunchgrass ranges of western North America are used as a model ecosystem for the impact of alien plants. Alien weed species have been introduced in successive waves, with the success of each new introduction dependent on how well adapted to the environment and how competitive the new weed is with those previously introduced. Annual species have been successful across extensive areas of Great Basin rangelands. Biennial and short- and long-lived perennial introductions have been restricted to much more specific habitats. Alien plants impact rangelands through stand renewal and successional processes. Alien weeds can cause such processes to be accelerated and/or truncated depending on the species and range site.

CRITERIA FOR SELECTING CHRYSOPA CARNEA BIOTYPES FOR BIOLOGICAL CONTROL: ADULT DIETARY REQUIREMENTS

1975 ◽  
Vol 107 (6) ◽  
pp. 589-595 ◽  
Author(s):  
Maurice J. Tauber ◽  
Catherine A. Tauber
Keyword(s):  
Biological Control ◽  
North America ◽  
West Coast ◽  
Biological Traits ◽  
The West ◽  
Control Programs ◽  
Preoviposition Period ◽  
Chrysopa Carnea ◽  
Control Adult ◽  
Agricultural Areas

AbstractBased on our studies with 10 geographic populations of Chrysopa carnea, we recommend that biological control programs involving this predator use "pure" carnea stock originating from eastern and midwestern North America. Of the two strains (races or biotypes) of C. carnea—carnea and mohave—carnea is the superior choice for biological control on commercial crops in both eastern and western North America because (1) its preoviposition period is approximately one-half as long as mohave’s, (2) unlike mohave adults, neither sex of the carnea strain requires prey for successful mating and initiating oviposition, (3) carnea’s oviposition can be enhanced in the field by applying currently available food sprays, and (4) carnea is efficient to mass-rear on a commercial basis.The “pure” mohave race is restricted to limited areas on the west coast. This race, which can enter a food-mediated summer diapause, is more suitable for biological control on the west coast in non-agricultural situations dominated by native vegetation, where prey occurrence is highly variable during summer.Most west coast populations in agricultural areas are composed of intermediates between the carnea and mohave races. F1 hybrids produced by crossing individuals from mohave, carnea, and intermediate populations, show predominantly carnea characteristics, and inheritance of the distinguishing biological traits appears to be controlled by polygenes.

THE BIOLOGY OF CANADIAN WEEDS.: 25. Silene alba (Miller) E. H. L. Krause

1977 ◽  
Vol 57 (4) ◽  
pp. 1103-1114 ◽  
Author(s):  
J. McNEILL
Keyword(s):  
Weed Species ◽  
Forage Crops ◽  
Silene Alba ◽  
Melandrium Album ◽  
Agricultural Areas

A review is provided of information on the biology of Silene alba (Lychnis alba, Melandrium album), a weed species introduced from Eurasia, which occurs across the agricultural areas of Canada. A serious weed, especially of leguminous forage crops, white cockle is resistant to common herbicides such as 2,4-D and 2,4,5-T.

scholarly journals Characterization and Pathogenicity of Rhizoctonia Species on Canola

Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 714-721 ◽  
Author(s):  
Ravjit K. Khangura ◽  
Martin J. Barbetti ◽  
Mark W. Sweetingham
Keyword(s):  
Root Rot ◽  
Seedling Emergence ◽  
Subterranean Clover ◽  
Enzyme Electrophoresis ◽  
Nuclear Staining ◽  
Damping Off ◽  
Weed Species ◽  
Bare Patch ◽  
Hyphal Morphology ◽  
Leguminous Crops

A total of 112 Rhizoctonia isolates were collected from various canola (Brassica napus) growing areas of Western Australia. Pectic enzyme electrophoresis differentiated these isolates into six distinct zymogram groups: R. solani, 54% ZG5 (AG2-1), 8% ZG6 (AG2-1), and 1% ZG9 (AG10); binucleate Rhizoctonia, 12% CZG1 (CAG1), 4% CZG4, and 6% CZG5 (AGK); and the remainder unidentified binucleate groups (15%). Binucleate groups were also confirmed by fluorescent nuclear staining and hyphal morphology. One or more isolates from each of the above zymogram groups (including four unidentified binucleate groups) and an isolate of ZG1-1 (AG8) that causes bare patch in cereals and legumes were tested for their pathogenicity on canola. Isolates of ZG5 and ZG1-1 were highly pathogenic on canola, delayed seedling emergence, and caused severe hypocotyl and root rot, respectively. ZG5 also induced postemergence damping-off. Increasing the depth of sowing from 1 to 3 cm significantly delayed seedling emergence and increased disease severity. Four unidentified binucleate isolates (WAC9316, WAC9297, WAC9307, and WAC9290) were moderately pathogenic to canola, while two isolates (WAC9307 and WAC9316) caused significant preemergence damping-off. Two CZG5 isolates were weakly pathogenic. Isolates of ZG5 and ZG1-1 were also tested for their pathogenicity on other rotational crops (narrow-leafed lupin, subterranean clover, wheat, oats, barley, and mustard) and two weed species (wild radish and annual ryegrass). ZG5 caused a severe hypocotyl rot on mustard and mild symptoms of hypocotyl rot on narrow-leafed lupin and clover, but failed to infect any of the cereal hosts, such as wheat, oats, barley, and ryegrass. In contrast, all crops tested were highly susceptible to ZG1-1 except mustard, which was only moderately susceptible. Results indicate that ZG5 is most pathogenic to crucifers and is a mildly virulent pathogen of the leguminous crops but not of cereal crops tested. ZG1-1, known to cause bare patch in legumes and cereals, also can cause severe root rot in canola. This is the first report of hypocotyl rot and pathogenicity of ZG5 on canola in Australia.

scholarly journals Weed Phytosociological and Floristic Survey in Agricultural Areas of Southwestern Goiás Region

2016 ◽  
Vol 34 (1) ◽  
pp. 65-80 ◽  
Author(s):  
SANTOS W.F. ◽  
PROCÓPIO S.O. ◽  
SILVA A.G. ◽  
FERNANDES M.F. ◽  
BARROSO A.L.L.
Keyword(s):  
Cropping Systems ◽  
Floristic Composition ◽  
Sampling Period ◽  
Weed Species ◽  
Floristic Survey ◽  
Commelina Benghalensis ◽  
Number Of Species ◽  
West Region ◽  
Weed Communities ◽  
Agricultural Areas

The use of the Roundup Ready(r) technology and the cultivation of a second crop influence the floristic composition of weed communities in Brazilian Central-West region cropping systems. This study has aimed to diagnose the dominant weed species in southwestern Goiás in areas of genetically-modified and conventional soybeans, using phytosociological and floristic surveys. Weed sampling was obtained by collecting all the plants present within a 0.5 m hollow frame, randomly thrown 20 times in each of thirty-five agricultural areas in the 2012/2013 harvest. Field survey was carried out in three periods: before desiccation for soybean sowing, before postemergence herbicide in soybean first application and before postemergence herbicide application in late harvest. A total of 525 m2 was inventoried and 3,219 weeds were collected, which included 79 species, 58 genera and 28 families. Families Poaceae, Asteraceae, Euphorbiaceae, Fabaceae, Amaranthaceae, were the most representative in the survey. Species Cenchrus echinatus, Glycine max, Chamaesyce hirta, Commelina benghalensis, and Alternanthera tenella stood out in importance. The RR+millet soybean treatment had the highest number of species (44), while the conventional soybean + sorghum treatment had the lowest number of species (18). The highest number of species was recorded in first sampling period. Treatments conventional soybean + maize and conventional soybean + millet showed higher similarity (70%), while treatments RR soybean + millet and conventional soybean + sorghum showed the least (51%). Species of difficult control were recorded in all cultivation systems analyzed.

scholarly journals COVER CROPS IN THE OFF-SEASON IN THE WEED MANAGEMENT AT NOTILLAGE AREA

2021 ◽  
Vol 34 (1) ◽  
pp. 50-57
Author(s):  
FERNANDO COUTO DE ARAÚJO ◽  
ADRIANO STEPHAN NASCENTE ◽  
JULIANA LOURENÇO NUNES GUIMARÃES ◽  
VINÍCIUS SILVA SOUSA ◽  
MARCO ANTÔNIO MOREIRA DE FREITAS ◽  
...  
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Dry Matter ◽  
Pennisetum Glaucum ◽  
Pigeon Pea ◽  
Weed Species ◽  
Agricultural Areas ◽  
Main Growth ◽  
Crotalaria Spectabilis

ABSTRACT Cover crops can provide suppression of weeds and together with chemical control make the proper management of weeds in agricultural areas. The objective of this study was to evaluate the effect of cover crop cultivation during the off-season on weed development in a no-tillage area. The experimental design was in randomized blocks scheme with six treatments and four replications. The treatments were: fallow (control), millet (Pennisetum glaucum) + crotalaria (Crotalaria spectabilis + C. juncea + C. ochroleuca), millet + pigeon pea (Cajanus cajans), millet + Urochloa ruziziensis, millet + Urochloa ruziziensis + pigeon pea and millet + buckwheat (Fagopyrum esculentum. The evaluations were done at 30, 75 and 225 days after sowing of the cover crops (DAS). The main growth weed species in the area were Cenchrus echinathus, Euphorbia heterophylla and Digitaria insularis. Fallow treatment showed greater number of weed species with density of 184 plants m-2, 9.0 species and with 527.8 g m-2 of dry matter mass at 225 DAS. In all treatments verified reduction in the density and mass of weeds dry matter compared to the fallow, with average of 30 plants m-2, 5.8 species and 7.9 g m-2 at 225 DAS, respectively. The use of cover crops is an important strategy for weed control in agricultural areas.

scholarly journals Reproductive biology in species of Bidens L. (Asteraceae)

2004 ◽  
Vol 61 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Maria Tereza Grombone-Guaratini ◽  
Vera Nisaka Solferini ◽  
João Semir
Keyword(s):  
Reproductive Biology ◽  
Conservation Biology ◽  
Agricultural Fields ◽  
Agricultural Crop ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Pollinator Community ◽  
Community Changes ◽  
Agricultural Areas ◽  
Disturbed Habitats

Studies about reproductive biology of weed species can have implications on the establishment of controlling practices that minimize the effects of these weed populations on agricultural fields. The pollination biology of Bidens alba (L.) DC., B. pilosa L., and Bidens subalternans DC., was studied at different sites and climatic seasons. Bidens pilosa and B. subalternans are widely distributed in agricultural areas, in disturbed habitats, and along road sides. Bidens alba occur only along the coast. The three species are self-compatible and non agamospermous. The composition of the pollinator community changes during the year and between sites. Hymenopterans and lepidopterans are the most frequent visitors to Bidens species in both areas studied. Although the species are self-compatible, the presence of pollinators may affect the levels of inbreeding. The attraction of insects by Bidens species may be benefical to agricultural crop and may also have important implications for conservation biology.

Pharmaceuticals in the Yamaska River, Quebec, Canada

2007 ◽  
Vol 42 (4) ◽  
pp. 231-239 ◽  
Author(s):  
Viviane Yargeau ◽  
Antonina Lopata ◽  
Chris Metcalfe
Keyword(s):  
Surface Water ◽  
North America ◽  
Water Samples ◽  
Pharmaceutically Active Compounds ◽  
Urban Centers ◽  
Basic Drug ◽  
Active Compounds ◽  
High Concentrations ◽  
Agricultural Areas ◽  
Surface Water Samples

Abstract Pharmaceutically active compounds have been detected in North America and Europe in groundwater, surface water, wastewater, and drinking water. In the province of Quebec in Canada, there has been little data to assess the occurrence of pharmaceutical residues in the aquatic environment. In August of 2005, samples of surface water were collected at 10 sites along the Yamaska River basin in Quebec, which passes through important agricultural areas and receives wastewater from several urban centers with populations ranging up to 44,000 residents. Several acidic drugs (naproxen, ibuprofen, gemfibrozil), neutral drugs (caffeine, carbamazepine, cotinine), and the sulfonamide antibiotic sulfamethoxazole were detected in the majority of the surface water samples. The antidepressant fluoxetine (neutral/basic drug) was not detected in any samples, while acetaminophen (acidic drug) was detected at only two sites, and sulfapyridine (sulfonamide antibiotic) was detected at only one site. Sulfamethoxazole and carbamazepine were present at the highest maximum concentrations of 578 ng/L and 106 ng/L, respectively. The concentrations of most of the target pharmaceutically active compounds observed in surface water samples within the watershed were generally consistent with the number of people in urban centers near the sampling sites when compared with other studies in urban watersheds. However, carbamazepine, naproxen, and sulfamethoxazole were present at surprisingly high concentrations for some of the low density areas. Overall, these results demonstrate that pharmaceuticals are distributed in surface waters within a watershed in Quebec at concentrations similar to levels observed in previous studies done in other parts of North America.

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