Pitted and Hybrid Morningglory Accessions Have Variable Tolerance to Glyphosate

2009 ◽  
Vol 23 (4) ◽  
pp. 592-598 ◽  
Author(s):  
Ian C. Burke ◽  
Krishna N. Reddy ◽  
Charles T. Bryson
Keyword(s):  
United States ◽  
Plant Growth ◽  
Weight Reduction ◽  
Related Species ◽  
Sublethal Dose ◽  
Southern United States ◽  
Fresh Weight ◽  
Leaf Stage ◽  
Pitted Morningglory ◽  
And Control

Two greenhouse studies were conducted to investigate the variability in tolerance to a sublethal dose of glyphosate among accessions of pitted morningglory, hybrid morningglory (a fertile hybrid between pitted and sharppod morningglory), and sharppod morningglory, collected from several states in the southern United States. The first study was conducted to evaluate the variability in tolerance to glyphosate among accessions. Glyphosate at 420 g ae/ha was applied to plants at the four- to five-leaf stage, and control (percent shoot fresh weight reduction) was determined 2 wk after treatment (WAT). Pitted morningglory response ranged from −9% (indicating no response to glyphosate) to 39% control. A similar trend was observed in hybrid morningglory. Control of two related species, cypressvine morningglory and red morningglory, averaged 40 and 29%, respectively, and was similar to control of the most susceptible pitted morningglory and hybrid morningglory accessions. Ivyleaf morningglory control was 9%. Sharppod morningglory control was highest (48%) among the morningglories studied. A second study was conducted to determine levels of tolerance to glyphosate based onGR50(dose required to cause a 50% reduction in plant growth) in 10 accessions that were least to most sensitive to glyphosate (7 pitted, 2 hybrid, and 1 sharppod morningglory). GlyphosateGR50doses ranged from 0.65 to 1.23 kg/ha, a two-fold variability in tolerance to glyphosate among the 7 pitted morningglory accessions. Increasing levels of tolerance were associated with the absence of a leaf notch. These results indicate the existence of variable tolerance to a sublethal dose of glyphosate among accessions of pitted morningglory.

Glyphosate-Resistant Goosegrass (Eleusine indica) Confirmed in Tennessee

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Thomas C. Mueller ◽  
Kelly A. Barnett ◽  
James T. Brosnan ◽  
Lawrence E. Steckel
Keyword(s):  
United States ◽  
Dry Weight ◽  
Southern United States ◽  
Future Research ◽  
Laboratory Studies ◽  
Fresh Weight ◽  
Control Data ◽  
Corn Production ◽  
Eleusine Indica ◽  
West Tennessee

Goosegrass is a problematic summer annual weed in cotton, soybean, and corn production in the southern United States. Glyphosate is labeled for POST control of goosegrass in glyphosate-resistant (GR) cotton, soybean, and corn production. A population of goosegrass in west Tennessee not controlled by glyphosate was examined in greenhouse and laboratory studies. At 21 days after treatment (DAT), a glyphosate-susceptible (SS) biotype was controlled > 90% with glyphosate at rates greater than 210 g ae ha−1. Comparatively, the GR biotype was only controlled 12% at 210 g ae ha−1. Using goosegrass control data, I50values for GR and SS biotypes were 868 and 117 g ae ha−1, susceptibility, resulting in a resistance factor (RF) of 7.4. Treatment with glyphosate at 210 g ae ha−1reduced fresh weight biomass of the SS biotype to 5 g per pot compared to 36 g for the GR biotype. A total of 3,360 g ae ha−1glyphosate was required to reduce fresh weights of the GR biotype to ∼5 g per pot. Using fresh and dry weight biomass data, I50values for the GR biotype were 3 to 10 times greater than the SS biotype. On each date from 1 to 6 DAT the SS biotype accumulated higher concentrations of shikimate than the GR biotype. Future research should evaluate strategies for managing GR goosegrass with alternative modes of action. To prevent the spread of resistance, additional research evaluating programs for managing glyphosate-susceptible goosegrass in GR crops is also warranted.

scholarly journals Evaluation of Cotton Cultivar and At-Plant Nematicide Application on Seasonal Populations of Reniform Nematode

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2166
Author(s):  
Whitney D. Crow ◽  
Angus L. Catchot ◽  
Darrin Dodds ◽  
Jeffery Gore ◽  
Donald R. Cook ◽  
...  
Keyword(s):  
United States ◽  
Plant Growth ◽  
Plant Biomass ◽  
Southern United States ◽  
Cotton Production ◽  
Growth Responses ◽  
Reniform Nematode ◽  
Rotylenchulus Reniformis ◽  
History Of ◽  
Cotton Cultivar

The reniform nematode, Rotylenchulus reniformis (Linford and Oliveira), remains a common, widespread nematode pest of cotton across the southern United States. Trials were conducted during 2017 at three non-irrigated locations: one location in Hamilton, MS, and two locations in Tchula, MS, in field settings with a history of cotton production and documented economically-damaging reniform nematode populations. Trials were designed to evaluate the response of two cotton cultivars to in-furrow nematicides consisting of aldicarb, 1,3-dichloropropene, and a non-treated control applied for nematode suppression. No significant interactions between cotton cultivar and nematicide were observed. However, treatment with 1,3-dichloropropene produced greater plant biomass, and plant height compared to aldicarb-treated cotton and the nontreated. Nematode densities were suppressed with the use of 1,3-dichloropropene compared to aldicarb and the non-treated control. The use of 1,3-dichloropropene resulted in positive early-season plant growth responses; however, these responses did not translate into greater yield.

TWO NEW ACANTHOSCELIDES (COLEOPTERA: BRUCHIDAE) FROM SOUTHERN UNITED STATES WITH NOTES ON RELATED SPECIES

1969 ◽  
Vol 101 (9) ◽  
pp. 975-983
Author(s):  
L. J. Bottimer
Keyword(s):  
United States ◽  
New Species ◽  
Host Plant ◽  
Related Species ◽  
Southern United States

AbstractAcanthoscelides mucrofer new species is described from Texas and A. helianthemum new species from Florida and Georgia. These are compared with A. tenuis Bottimer and A. atomus (Fall), respectively. Photographs of the four species are included. A. helianthemum had been previously reported from Florida under the name Bruchus compressicornis Schaeffer. The host plant of A. mucrofer is unknown. The following rearing records are reported: A. tenuis from Lythrum alatum and L. lineare; A. helianthemum from Helianthemum corymbosum; A. atomus from Lechea tenuifolia and L. racemulosa; and A. compressicornis from Desmanthus virgatus.

Bentazon Spray Retention, Activity, and Foliar Washoff in Weed Species

1995 ◽  
Vol 9 (4) ◽  
pp. 773-778 ◽  
Author(s):  
Krishna N. Reddy ◽  
Martin A. Locke ◽  
Kevin D. Howard
Keyword(s):  
Nonionic Surfactant ◽  
Weight Reduction ◽  
Simulated Rainfall ◽  
Fresh Weight ◽  
Weed Species ◽  
Leaf Stage ◽  
Shoot Fresh Weight ◽  
Hemp Sesbania ◽  
Smooth Pigweed

Greenhouse studies were conducted to investigate the effects of adjuvant and rainfall on bentazon spray retention, efficacy, and foliar washoff in hemp sesbania, sicklepod, smooth pigweed, and velvetleaf. Bentazon was applied at 0.28 to 2.24 kg ai/ha with Agri-Dex, a crop oil concentrate (COC) or Kinetic, an organiosilicone-nonionic surfactant blend (OSB) when weeds were at the three- to five-leaf stage. Plants were subjected to 2.5 cm simulated rainfall for 20 min at 1 and 24 h after application of bentazon. Shoot fresh weight reduction assessed 2 wk after treatment was similar with either adjuvant on velvetleaf and smooth pigweed. OSB enhanced bentazon efficacy in hemp sesbania and sicklepod as compared to COC. Rainfall at 1 h after application generally reduced bentazon activity in all weeds. OSB maintained bentazon activity in hemp sesbania when subjected to rainfall at 1 h after application as compared to COC. Overall, bentazon spray retention on plants was 9 to 550% higher with OSB as compared to COC among the species at 1 h after application. Amount of bentazon residue washed off from the foliage by rainfall within a weed species was relatively similar for both adjuvants except in smooth pigweed and ranged from 39 to 98% among the four weed species at 1 h after application. OSB exhibited specificity for certain weed species and the potential to minimize bentazon spray reaching the soil by increasing deposition.

scholarly journals The Effect of Genotype on Winter Production of Collard and Kale in the Southeastern United States

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 821B-821
Author(s):  
Mark W. Farnham ◽  
T. Garrett
Keyword(s):  
United States ◽  
South Carolina ◽  
Brassica Oleracea ◽  
Southeastern United States ◽  
Fresh Weight ◽  
Leaf Production ◽  
Leaf Stage

Collard and kale (Brassica oleracea L. var. acephala) cultivars and several landraces obtained from southeastern growers were tested for potential winter production. Collard and kale entries were grown in four winter environments in South Carolina from 1993 to 1995. Transplants were set in the field during November or December, and leaf production and plant fresh weight were monitored through the winter. When plants reached a 22-leaf stage, a plot subsample was harvested and weighed. The date at which 50% of the plants per plot had bolted was also recorded. Essentially all entries survived the conditions of four winter environments. However, whether an entry reached harvest size depended on its date of bolting. Collard entries typically bolted earlier than kale entries, and most kale and several collard entries attained harvestable-size before bolting. The ranking of genotypes for days to 50% bolting was consistent among environments. `Blue Max' and a landrace of collard, and `Squire' and `Blue Knight' kale usually never reached 50% bolt.

English Ivy (Hedera helix) Control with Postemergence-Applied Herbicides

2013 ◽  
Vol 6 (3) ◽  
pp. 411-415 ◽  
Author(s):  
Qian Yang ◽  
Glenn Wehtje ◽  
Charles H. Gilliam ◽  
J. Scott McElroy ◽  
Jeff L. Sibley
Keyword(s):  
United States ◽  
Weight Reduction ◽  
Large Population ◽  
The United States ◽  
Control Treatment ◽  
Fresh Weight ◽  
Hedera Helix ◽  
English Ivy

AbstractEnglish ivy (Hedera helix) is an evergreen, perennial vine that was introduced from Europe and Asia and is not endemic in much of the United States. English ivy can be invasive and difficult to control once established. Four similar, but not identical, experiments were conducted in sequence to evaluate selected, POST-applied herbicides for English ivy control. English ivy plants were propagated from cuttings and container-grown to obtain a large population of uniform plants. Aminopyralid and fluroxypyr applied at 1.34 and 0.71 kg ae ha−1, which is more twice the maximum registered rate for either herbicide, were ineffective. Glyphosate and 2,4-D amine were generally more effective, but neither herbicide provided a level of control that could be deemed consistently acceptable. Glyphosate applied at 8.51 kg ae ha−1 (the highest rate evaluated) provided 69, 98, and 89% control in the second, third, and fourth experiments as determined by foliage fresh-weight reduction relative to a nontreated control. Treatment with 2,4-D at 5.60 kg ae ha−1 (the highest rate evaluated) controlled English ivy 28, 98, and 89% in the second, third, and fourth experiments, respectively. Mixtures of 2,4-D and glyphosate were generally no more effective than were the components applied alone. Metsulfuron was the most effective herbicide. Metsulfuron applied at 0.168 kg ai ha−1 controlled English ivy ≥ 97% across the three experiments in which this treatment was included. This treatment also prevented regrowth.

Identification and Control of Invasive Privets (Ligustrum spp.) in the Middle Southern United States

2010 ◽  
Vol 3 (4) ◽  
pp. 482-488 ◽  
Author(s):  
Victor Maddox ◽  
John Byrd ◽  
Brett Serviss
Keyword(s):  
United States ◽  
Introduced Species ◽  
Reference Materials ◽  
Species Distributions ◽  
Population Data ◽  
Southern United States ◽  
Management Options ◽  
Species Population ◽  
Pertinent Information ◽  
And Control

AbstractThe identification of privet in the middle southern United States can be difficult. Because most introduced species of privet can be invasive, and recent mapping projects seek location and species population data, proper identification is important. Without proper identification of privet species, data on species distributions and other pertinent information regarding invasiveness could lead to improper conclusions. Currently, information on privet identification is scattered throughout a number of reference materials. The purpose of this publication is to assist with the proper identification of escaped privet species, and suggest management options.

Interference and Control of Glyphosate-Resistant and -Susceptible Palmer Amaranth (Amaranthus palmeri) Populations under Greenhouse Conditions

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 259-266 ◽  
Author(s):  
Aman Chandi ◽  
David L. Jordan ◽  
Alan C. York ◽  
Susana R. Milla-Lewis ◽  
James D. Burton ◽  
...  
Keyword(s):  
North Carolina ◽  
Weight Reduction ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Fresh Weight ◽  
Percent Reduction ◽  
Snap Bean ◽  
Crop Height ◽  
And Control ◽  
Bean Crop

Interference for 40 d after emergence (DAE) of corn, cotton, peanut, and snap bean by four glyphosate-resistant (GR) and four glyphosate-susceptible (GS) Palmer amaranth populations from Georgia and North Carolina was compared in the greenhouse. Greater interference from Palmer amaranth, measured as crop height and fresh weight reduction, was noted in cotton and peanut compared with corn or snap bean. Crop height 15 to 40 DAE was reduced similarly by GR and GS populations. Crop fresh weight, however, was reduced 25 and 19% in the presence of GS and GR populations, respectively. Measured as percent reduction in fresh weight, GR and GS populations of Palmer amaranth were controlled similarly by glufosinate, lactofen, paraquat, and trifloxysulfuron applied POST. Atrazine and dicamba controlled GR populations more effectively than GS populations.

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