scholarly journals Using a Buckwheat Cover Crop for Maximum Weed Suppression after Early Vegetables

2013 ◽  
Vol 23 (5) ◽  
pp. 575-580 ◽  
Author(s):  
Thomas Björkman ◽  
Joseph W. Shail
Keyword(s):  
United States ◽  
Cover Crop ◽  
Field Experiments ◽  
Growing Season ◽  
The United States ◽  
Weed Suppression ◽  
Optimal Timing ◽  
Northeastern United States ◽  
Geographical Regions ◽  
Short Growing Season

Establishment of a weed-suppressive cover crop after vegetables harvested early in the season is important in the northeastern United States because of the short growing season. Buckwheat (Fagopyrum esculentum) is an effective cover crop in vegetable production because of its short growing season, ability to outcompete many weeds, resistance to damage by insects and disease, and requirement for only moderate soil fertility. In two separate 3-year field experiments, we determined the best tillage techniques and the optimal timing for use of buckwheat as a cover crop after early vegetables in the northeastern United States. Incorporating crop residue with a disk was necessary and provided sufficient tillage to obtain a weed-suppressive buckwheat stand. Buckwheat growth was stunted when direct seeded with a no-till drill immediately after pea (Pisum sativum) harvest because of poor soil penetration by buckwheat roots. Planting buckwheat after incorporating the pea crop was successful; waiting 1 week to plant was optimal, whereas a 2-week wait produced a weaker stand. We determined that optimal timing for sowing buckwheat in central New York was late June to early August. Generalizing to other geographical regions in the United States, we calculated that a minimum accumulation of 700 growing degree days is necessary to reach 1 to 1.5 tons/acre of buckwheat dry matter at the appropriate growth stage for incorporation (6 weeks after sowing).

Existence of Ecotypes Among Populations of Entireleaf Morningglory (Ipomoea hederaceavar.integriuscula)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 540-544 ◽  
Author(s):  
Tracy E. Klingaman ◽  
Lawrence R. Oliver
Keyword(s):  
United States ◽  
Field Experiments ◽  
Leaf Surface ◽  
Dry Weight ◽  
Growing Season ◽  
The United States ◽  
Trichome Density ◽  
Vegetative Phase ◽  
Northern Latitudes ◽  
Total Dry Weight

Field experiments were conducted using entireleaf morningglory seed collected from areas of adaptation throughout the United States to determine whether biotypes or ecotypes exist and whether differences in susceptibility to acifluorfen exist. Initiation of first flower for the entireleaf morningglory populations ranged from 63 to 81 d after emergence. The interval between emergence and initiation of first flower decreased 2.8 d for each increase in degree of latitude from which the seed was collected. Plants originating from southern latitudes remained in the vegetative phase longer and tended to produce more total dry-weight biomass than plants originating from northern latitudes. Thus, ecotypes do exist for entireleaf morningglory because of adaptation to a specific environment. The adaptation allows ecotypes to utilize the length of the growing season associated with the area of origin. Trichome density on the adaxial leaf surface ranged from 147 to 206 cm−2across the ecotypes and was not correlated with latitude or differences in acifluorfen susceptibility. Ecotypes differed in susceptibility to acifluorfen, but resistance among ecotypes was not evident.

scholarly journals Interaction of dicamba, fluthiacet-methyl, and glyphosate for control of velvetleaf (Abutilon theopharsti) in dicamba/glyphosate-resistant soybean

2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala
Keyword(s):  
United States ◽  
Field Experiments ◽  
The United States ◽  
Application Rate ◽  
Herbicide Application ◽  
Soybean Yield ◽  
Agronomic Crops ◽  
Split Plot ◽  
Main Plot ◽  
Biomass Reduction

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.

scholarly journals Prevalence of single and coinfections of human pathogens in Ixodes ticks from five geographical regions in the United States, 2013–2019

2021 ◽  
Vol 12 (2) ◽  
pp. 101637
Author(s):  
Aine Lehane ◽  
Sarah E. Maes ◽  
Christine B. Graham ◽  
Emma Jones ◽  
Mark Delorey ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Human Pathogens ◽  
Geographical Regions ◽  
Ixodes Ticks

scholarly journals Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 263-268 ◽  
Author(s):  
S. K. Gremillion ◽  
A. K. Culbreath ◽  
D. W. Gorbet ◽  
B. G. Mullinix ◽  
R. N. Pittman ◽  
...  
Keyword(s):  
United States ◽  
Disease Resistance ◽  
Leaf Spot ◽  
Field Experiments ◽  
Disease Incidence ◽  
The United States ◽  
Yield Potential ◽  
Cercospora Arachidicola ◽  
Breeding Lines ◽  
Progress Curve

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

scholarly journals Consumer Preferences for Oyster Attributes: Field Experiments on Brand, Locality, and Growing Method

2017 ◽  
Vol 46 (2) ◽  
pp. 315-337 ◽  
Author(s):  
Maik Kecinski ◽  
Kent D. Messer ◽  
Lauren Knapp ◽  
Yosef Shirazi
Keyword(s):  
United States ◽  
Field Experiments ◽  
Consumer Preferences ◽  
Revealed Preference ◽  
The United States ◽  
Dichotomous Choice ◽  
Production Methods ◽  
The Past ◽  
Oyster Aquaculture ◽  
First Time

Oyster aquaculture has experienced tremendous growth in the United States over the past decade, but little is known about consumer preferences for oysters. This study analyzed preferences for oysters with varied combinations of brands, production locations, and production methods (aquaculture vs. wild-caught) using dichotomous choice, revealed preference economic field experiments. Results suggest significant and distinct differences in behavior between first-time and regular oyster consumers. While infrequent oyster consumers were drawn to oysters labeled as wild-caught, experienced oyster consumers preferred oysters raised via aquaculture. These findings will be valuable for growers and policymakers who invest in aquaculture to improve surrounding ecosystems.

Abstract 119: Initiating Oral Anticoagulation 4 to 14 Days After a Cardioembolic Stroke is Not Associated With a Reduction in Ischemic or Hemorrhagic Events: The IAC Multicenter Cohort

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Shadi Yaghi ◽  
Tushar Trivedi ◽  
James Giles ◽  
Angela Liu ◽  
Muhammad Nagy ◽  
...  
Keyword(s):  
United States ◽  
Oral Anticoagulation ◽  
Infarct Volume ◽  
Recurrent Stroke ◽  
Composite Endpoint ◽  
The United States ◽  
Cardioembolic Stroke ◽  
Optimal Timing ◽  
Symptomatic Intracerebral Hemorrhage ◽  
Ischemic Events

Background/Aims: Guidelines suggest initiating anticoagulation after cardioembolic stroke within 4-14 days from the index event. Data supporting this suggestion did not account for important factors such as infarct burden or early hemorrhagic transformation. Methods: We pooled data from stroke registries of 8 comprehensive stroke centers across the United States. We included consecutive patients admitted with an acute cardioembolic stroke in the setting of atrial fibrillation. The primary predictor was timing of initiating anticoagulation (0-3 days, 4-14 days, or >14 days) and the primary outcome was the composite endpoint of recurrent stroke/TIA/systemic embolism, symptomatic intracerebral hemorrhage (sICH), or major extracranial hemorrhage (ECH) within 90 days. Results: We enrolled 2090 patients from 8 comprehensive centers in the United States, 1325 met the inclusion criteria (362 were excluded due to non-composite endpoint related death within 90 days, 145 lost to follow up, and 258 were not started on oral anticoagulation or the timing was not reported). Anticoagulation (875 DOAC, 404 Warfarin) was initiated in 0-3 days in 49.7%, 4-14 days in 40.4%, and >14 days in 9.9%. The combined endpoint occurred in 10.7% (142) (98 ischemic events, 21 sICH, and 30 ECH) and did not differ between the three groups: 0-3 days (11.9%), 4-14 days (9.9%), >14 days (9.9%), p=0.525. After adjusting for confounders (such as infarct volume, bridging, CHADS2-Vasc, cardiac thrombus, and hemorrhage on 24-hr imaging), oral anticoagulation timing in the 4-14 day period (vs. >14) was not associated with a reduction in ischemic events (adjusted OR 0.74, p=0.438) and oral anticoagulation timing 4-14 days (vs. 0-3) was not associated with a reduction in sICH (OR 1.28, p=0.638). Factors associated with sICH were bridging (OR 5.36, p=0.001) and hemorrhage on 24-hr imaging (OR 7.26, p<0.001) whereas for ischemic events were warfarin treatment (OR 1.66 95%, p = 0.030) and prior stroke (OR 1.81, p=0.013). Conclusion: In this multicenter real world cohort, the recommended (4-14 days) timeframe to start oral anticoagulation was not associated with reduced ischemic and hemorrhagic outcomes. Randomized trials are required determine the optimal timing of anticoagulation initiation.

Coleopteran Pests: Family Scarabaeidae

2020 ◽  
pp. 161-173
Author(s):  
Patricia J. Vittum
Keyword(s):  
United States ◽  
The United States ◽  
Southwestern United States ◽  
Northeastern United States ◽  
White Grubs ◽  
Large Complex ◽  
The Family ◽  
Major Pest ◽  
General Appearance

This chapter studies Coleopteran pests. The larvae of turfgrass-infesting species of the family Scarabaeidae constitute a large complex whose members (white grubs) are similar in general appearance, in habits, and in the turfgrass damage they cause. At least 10 species of scarabs, belonging to five subfamilies, are pests of turfgrass in the United States. The larvae of this family are known also as grubs, a term applied to the larvae of several Coleoptera (beetles) and Hymenoptera (ants, bees, and wasps) in general. Grubs of the Scarabaeidae are the most serious turfgrass pests in the northeastern United States, and are considered a major pest in the Midwest, Southeast, and parts of the southwestern United States. Their subterranean habits make them among the most difficult of turfgrass insects to manage.

scholarly journals Alternative Hosts in the Families Poaceae and Cyperaceae for Xanthomonas vasicola pv. vasculorum, Causal Agent of Bacterial Leaf Streak of Corn

2020 ◽  
Vol 110 (6) ◽  
pp. 1147-1152 ◽  
Author(s):  
T. Hartman ◽  
B. Tharnish ◽  
J. Harbour ◽  
G. Y. Yuen ◽  
T. A. Jackson-Ziems
Keyword(s):  
United States ◽  
Festuca Arundinacea ◽  
Field Experiments ◽  
The United States ◽  
Phleum Pratense ◽  
Schizachyrium Scoparium ◽  
Big Bluestem ◽  
Bacterial Leaf Streak ◽  
Alternative Hosts ◽  
Palm Species

The bacterial pathogen Xanthomonas vasicola pv. vasculorum was first reported in the United States causing bacterial leaf streak on Nebraska corn (Zea mays) in 2016. The bacterium is also known to cause disease in sugarcane, grain sorghum, broom bamboo, and various palm species. The objective of this study was to identify alternative hosts for X. vasicola pv. vasculorum among plants commonly found in corn growing areas of the United States. In repeated greenhouse experiments, 53 species of plants found in the United States that had not been tested previously for susceptibility to X. vasicola pv. vasculorum were inoculated with the pathogen and monitored for symptom development. Eleven species in the family Poaceae exhibited symptoms: oat (Avena sativa), rice (Oryza sativa), orchardgrass (Dactylis glomerata), indiangrass (Sorghastrum nutans), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), timothy (Phleum pratense), sand bluestem (Andropogon hallii), green foxtail (Setaria viridis), bristly foxtail (Setaria verticillata), and johnsongrass (Sorghum halepense). Yellow nutsedge (Cyperus esculentus) in the Cyperaceae also was a symptomatic host. In addition, endophytic colonization by X. vasicola pv. vasculorum was found in three asymptomatic alternative hosts: downy brome (Bromus tectorum), tall fescue (Festuca arundinacea), and western wheatgrass (Pascopyum smithii). Experiments were also conducted in the field to determine the potential for alternative hosts to become infected by natural inoculum. Symptoms developed only in big bluestem and bristly foxtail in field experiments. These results suggest that infection of alternative hosts by X. vasicola pv. vasculorum can occur, but infection rates might be limited by environmental conditions.

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