scholarly journals Management options for large plants of glyphosate-resistant feather fingergrass (Chloris virgata) in Australian fallow conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261788
Author(s):  
Bhagirath Singh Chauhan ◽  
Mark Congreve ◽  
Gulshan Mahajan
Keyword(s):  
Growth Stage ◽  
Eastern Region ◽  
Limited Information ◽  
Plant Mortality ◽  
Management Options ◽  
Complete Control ◽  
Leaf Stage ◽  
Application Rates ◽  
Chloris Virgata ◽  
Biomass Reduction

Chloris virgata has become one of the most difficult glyphosate-resistant (GR) grass weeds in summer fallows in the eastern region of Australia. It germinates in several cohorts following rainfall events; therefore, growers are often tempted to wait for most of the weeds to emerge before herbicide application. However, by that time, some seedlings have reached an advanced stage and there is limited information on the efficacy and reliability of alternate herbicides when targeting large plants of GR C. virgata. A series of experiments were conducted to determine the efficacy of alternate herbicides for the control of GR C. virgata. Haloxyfop (80 g a.i. ha-1) on its own, in mixtures, or sequential applications of haloxyfop and paraquat or glufosinate provided 97 to 100% mortality of the 8–10 leaf stage plants. Glufosinate (1500 g a.i. ha-1) also provided complete control of plants at this growth stage. For larger plants at the 24–28 leaf stage, glufosinate, with or without additional tank-mixed adjuvants, generally did not provide full control, however did show very high levels of biomass reduction and panicle suppression at application rates of 750 or 1500 g a.i. ha-1. Haloxyfop (40 to 160 g a.i. ha-1) and clethodim (180 g a.i. ha-1) on their own achieved 96 to 100% mortality at this growth stage. When applied to large plants (40–50 leaf stage), a tank-mix of isoxaflutole plus paraquat demonstrated significantly higher levels of plant mortality and biomass reduction than either herbicide used alone, and this mixture appears to be synergistic when tested via the Colby equation for synergy or antagonism. Plant mortality was greater (83%) when isoxaflutole (75 g a.i. ha-1) plus paraquat (300 g a.i. ha-1) was taken up through the foliage and soil, compared with the foliage alone. This study identified alternative herbicide options for large plants of GR C. virgata.

Winter Wheat (Triticum aestivum) Growth Stage Effect on Paraquat Bioactivity

1991 ◽  
Vol 5 (2) ◽  
pp. 439-441
Author(s):  
Randy L. Anderson ◽  
David C. Nielsen
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Growth Stage ◽  
Time Of Day ◽  
Growth Stages ◽  
Leaf Stage ◽  
Time Of Application ◽  
Biomass Reduction

Paraquat was applied at 0.28 and 0.56 kg ai ha-1to winter wheat at five growth stages at 0800, 1300, and 1600 hr to determine whether growth stage or time of application influenced winter wheat response to paraquat. Paraquat bioactivity was affected by growth stage. Biomass reduction by paraquat was 84% when winter wheat was in the 1 to 3 leaf stage, but only 68% when application was delayed until tillering. Paraquat bioactivity continued to decrease at later growth stages. The time of day when paraquat was applied did not affect its bioactivity on winter wheat.

Efficacy of PRE and POST Herbicides for Control of Citron Melon (Citrullus lanatusvar.citroides)

2012 ◽  
Vol 26 (4) ◽  
pp. 783-788 ◽  
Author(s):  
Analiza Henedina M. Ramirez ◽  
Amit J. Jhala ◽  
Megh Singh
Keyword(s):  
Growth Stage ◽  
Field Conditions ◽  
Limited Information ◽  
Leaf Stage ◽  
Herbicide Treatments ◽  
Citrus Orchards ◽  
Florida Citrus

Citron melon is a monoecious and hairy annual vine commonly found in citrus orchards and cotton and peanut fields. There is limited information available on citron melon control with PRE- and POST-applied herbicides in Florida citrus. Experiments were conducted to evaluate the response of citron melon to 11 PRE and 18 POST herbicides under greenhouse conditions. Indaziflam applied PRE at 0.095 kg ai ha−1resulted in 13% citron melon emergence at 14 d after treatment (DAT). The majority of PRE herbicides did not affect emergence at 14 DAT. Efficacy of PRE herbicides at 21 DAT resulted in > 90% control of citron melon with bromacil, premix formulation of bromacil + diuron, flumioxazin, indaziflam at 0.073 and 0.095, norflurazon, and simazine. Citron melon control was < 30% 21 DAT following PRE-applied diuron, oryzalin, and flazasulfuron. Control of citron melon varied by POST herbicides and growth stage. Regardless of citron melon growth stage, glyphosate, glufosinate, saflufenacil, paraquat, and flumioxazin provided > 90% at 7 and 14 DAT. Carfentrazone, flazasulfuron, imazapic, pyrithiobac-Na, rimsulfuron, trifloxysulfuron, and premix of 2,4-D + glyphosate controlled citron melon at least 90% when applied to two- to four-leaf plants. Control was reduced when application was delayed to the six- to eight-leaf stage. Bentazon and halosulfuron controlled citron melon 11 to 31% regardless of growth stage. Biomass of citron melon at 14 DAT was reduced > 50% in all herbicide treatments except with bentazon and halosulfuron applied at both stages, and dicamba, mesotrione, imazapic, and rimsulfuron applied to six- to eight-leaf citron melon. The results of this study indicate that citron melon can be adequately controlled with several PRE- or POST-applied herbicides; however, research is required to evaluate PRE followed by POST programs or their tank mixtures for season-long control of citron melon under field conditions.

Plant mortality and seedling recruitment responses to flupropanate in grassland populations of Nassella trichotoma

2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville
Keyword(s):  
New Zealand ◽  
Dose Response ◽  
Sodium Salt ◽  
Seedling Recruitment ◽  
Residual Activity ◽  
Application Rate ◽  
Plant Mortality ◽  
Complete Control ◽  
Bio Synthesis

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.

scholarly journals Sensitivity and Recovery of Grain Sorghum to Simulated Drift Rates of Glyphosate, Glufosinate, and Paraquat

Agriculture ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 70 ◽  
Author(s):  
Ralph Hale ◽  
Taghi Bararpour ◽  
Gurpreet Kaur ◽  
John Seale ◽  
Bhupinder Singh ◽  
...  
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Grain Sorghum ◽  
Yield Reduction ◽  
Leaf Stage ◽  
Herbicide Treatments ◽  
Significant Yield ◽  
Glyphosate Drift ◽  
Herbicide Drift

A field experiment was conducted in 2017 and 2018 to evaluate the sensitivity and recovery of grain sorghum to the simulated drift of glufosinate, glyphosate, and paraquat at two application timings (V6 and flag leaf growth stage). Paraquat drift caused maximum injury to sorghum plants in both years, whereas the lowest injury was caused by glyphosate in 2017. Averaged over all herbicide treatments, injury to grain sorghum from the simulated herbicide drift was 5% greater when herbicides were applied at flag leaf stage, as compared to herbicide applications at the six-leaf stage in 2017. In 2018, injury from glyphosate drift was higher when applied at the six-leaf stage than at the flag leaf stage. Paraquat and glufosinate drift caused more injury when applied at flag leaf stage than at six-leaf stage at 14 days after application in 2018. About 21% to 29% of injury from the simulated drift of paraquat led to a 31% reduction in grain sorghum yield, as compared to a nontreated check in 2017. The simulated drift of glyphosate and glufosinate did not result in any significant yield reduction compared to the nontreated check in 2017, possibly due to the recovery of sorghum plants after herbicides’ drift application.

Effect of Haloxyfop on Quackgrass (Elytrigia repens) and Potatoes (Solanum tuberosum)

1991 ◽  
Vol 5 (1) ◽  
pp. 72-75 ◽  
Author(s):  
Jerry A. Ivany
Keyword(s):  
Adverse Effect ◽  
Solanum Tuberosum ◽  
Potato Yield ◽  
No Removal ◽  
Leaf Stage ◽  
Application Rates ◽  
Elytrigia Repens

Reduction of initial top growth of quackgrass with haloxyfop at 0.13 kg ai ha-1and above in the greenhouse was comparable at the 2-, 4-, and 6-leaf stages. Quackgrass control was not affected by rhizome length in plants grown from 2-node and 10-node rhizome pieces. Removal of quackgrass shoots 6 h after treatment resulted in increased initial topgrowth, regrowth, and rhizome weight at all application rates when compared to treatments with no removal of shoots; however, growth decreased with increasing rates of haloxyfop. Later removal at 24 or 96 h after treatment did not affect quackgrass control, indicating rapid translocation. In field-grown potato, haloxyfop applied at 0.25 kg ha-1at the 4- to 5-leaf stage controlled more than 80% of quackgrass. Lower rates controlled less than 80% when used alone; but adding cultivation improved control. No adverse effect on potato yield was noted with haloxyfop.

scholarly journals Seroprevalence of Toxoplasma gondii infection and variables associated with seropositivity in donkeys in eastern China

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 66 ◽  
Author(s):  
Qing-Feng Meng ◽  
Dan Li ◽  
Gui-Zhe Yao ◽  
Yang Zou ◽  
Wei Cong ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Feeding Habits ◽  
Eastern China ◽  
Shandong Province ◽  
Eastern Region ◽  
Limited Information ◽  
Equus Asinus ◽  
Toxoplasma Gondii Infection ◽  
Production Areas ◽  
And Control

Donkeys (Equus asinus) are widely distributed throughout China; they are used for their meat, as food, and certain donkey-derived items are also important for traditional Chinese medicinal purposes. However, only limited information is available on Toxoplasma gondii infection in donkeys in China, especially the eastern region, which is one of the largest production areas. Thus, the present study was conducted to detect specific anti-T. gondii antibodies using a commercially available indirect hemagglutination test (IHA) kit and to evaluate the risk factors that are associated with seroprevalence in the Shandong province of eastern China. A total of 213/1278 (17%) donkeys tested from Shandong province were positive for T. gondii antibodies. Statistical analysis revealed that gender and feeding habits of the animal are associated with T. gondii infection. These results provide information for the prevention and control of toxoplasmosis in donkeys, other animals, and humans in this region and elsewhere.

scholarly journals Format of a Weed Control Database

1991 ◽  
Vol 5 (1) ◽  
pp. 221-228 ◽  
Author(s):  
George W. Mueller-Warrant
Keyword(s):  
Weed Control ◽  
Growth Stage ◽  
Information Access ◽  
Database Systems ◽  
Original Data ◽  
Relevant Information ◽  
Growth Stages ◽  
Complete Control ◽  
Large Numbers ◽  
Effect Level

Access to detailed descriptions of the effects of applying specific rates of herbicides to crops and weeds in various growth stages is hampered by the format in which the relevant information is stored. Compared to traditional formats of journal articles and herbicide registration labels, computer database systems could easily cross-reference data from large numbers of experiments and answer specific questions concerning herbicide performance under particular conditions. Availability of this type of information could have far-reaching consequences for herbicide users, consultants, researchers, and regulators. A preliminary format for storing weed control information in IBM-PC compatible computers was developed, including procedures to enter data and retrieve information. Weed control efficacy or crop injury data for all rates of a herbicide or tank-mixture applied at a specific growth stage in a single test are used to generate dose/response equations by means of regression analysis routines. The best fitting of these equations is then used to estimate herbicide rates that would provide ten categories of control, ranging from a “no observable effect level” (NOEL) up to complete control. Rates are estimated only for those categories either within or bordering the range of the observed data, the remaining categories are empty. The estimated rates are stored in the database, along with the original data and other qualifying information. Access to information is organized around searches for a single herbicide, plant species, or pair of species. Search output is presented in a tabular format listing species, growth stage, herbicide name, and herbicide rates for the ten categories: NOEL, 10, 30, 50, 70, 83, 90, 95, 98, and 100% control or injury.

scholarly journals Characteristics and risk factors of Plasmodium falciparum malaria in Eastern and Central Nepal

1970 ◽  
Vol 7 (4) ◽  
pp. 378-382 ◽  
Author(s):  
MR Banjara ◽  
W Sirawaraporn ◽  
S Petmitr ◽  
M Imwong ◽  
AB Joshi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Falciparum Malaria ◽  
Central Region ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Eastern Region ◽  
Limited Information ◽  
Laboratory Assessment ◽  
Cross Sectional ◽  
Central Nepal

Background: Very limited information is available on epidemiology of falciparum malaria in Nepal. Such information is very important for malaria control programmes. It is believed that malaria in Eastern region is imported from border districts of India and local transmission follows whereas it is indigenous in Central region. Therefore, the characteristics and risk factors of malaria are believed to be different in Eastern and Central Nepal. Objective: The objective of the study is to describe and compare the characteristics and risk factors of falciparum malaria in Eastern and Central Nepal. Materials and methods: This cross-sectional study was conducted in falciparum malaria endemic districts of Eastern and Central Nepal, during the period 2007 to 2008. We identified and collected information from 106 patients (62 from Eastern and 44 from Central region). Patient examination, clinical and laboratory assessment were done and patients were interviewed using structured questionnaire for malaria related characteristics, risk factors and behaviours. Results: There were significant differences in risk factors and characteristics of falciparum malaria in the Central than the Eastern region. In the Central region, male, illiteracy and thatched roof hut were significant risk factors of falciparum malaria patients as compared to the Eastern region. Visits outside within one months, previous malaria within three months, taking antimalarial before confirmatory diagnosis were significantly higher in patients of the Eastern region as compared to the Central region. Conclusion: Falciparum malaria in Nepal should not be seen as similar entity, and different strategies for prevention and control is needed for its diverse characteristics and endemicity. Key words: Eastern and Central Nepal; falciparum malaria; risk factors DOI: 10.3126/kumj.v7i4.2758 Kathmandu University Medical Journal (2009) Vol.7, No.4 Issue 28, 378-382

The applicability of the cognitive abilities screening instrument–short (CASI-S) in primary care in Brazil

2015 ◽  
Vol 28 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Glaucia Martins de Oliveira ◽  
Juliana Emy Yokomizo ◽  
Laís dos Santos Vinholi e Silva ◽  
Laura Ferreira Saran ◽  
Cássio M. C. Bottino ◽  
...  
Keyword(s):  
Primary Care ◽  
Internal Consistency ◽  
Cognitive Abilities ◽  
Temporal Stability ◽  
Screening Instrument ◽  
Eastern Region ◽  
Limited Information ◽  
Cognitive Screening ◽  
Dementia Patients ◽  
Normal Controls

ABSTRACTBackground:The Cognitive Abilities Screening Instrument – Short (CASI-S) is a brief cognitive screening test. However, there is limited information regarding its applicability in primary care.Objectives:To ascertain whether the CASI-S differentiates between dementia patients and normal controls in primary care; to examine its correlation with other cognitive instruments, to analyze its internal consistency, test-retest stability, and diagnostic accuracy.Methods:In a case-control study, carried out at two Primary Care Units (PCUs) in the eastern region of the city of São Paulo, 47 older adults were diagnosed with dementia according to DSM-IV criteria (mean age = 76.81 ± 7.03 years), and 55 were classified as normal controls (mean age = 72.78 ± 7.37 years), by a multidisciplinary panel which had access to results from a comprehensive cognitive battery and the patients’ health data. The present analyses included results from the Mini-Mental State Examination (MMSE). The CASI-S was not used to determine diagnostic status.Results:The CASI-S was easily applied in the primary care setting. There was a significant performance difference (p < 0.001) between dementia patients (15.57 ± 7.40) and normal controls (26.67 ± 3.52) on the CASI-S. CASI-S scores correlated with age (ρ = −0.410, p < 0.001), educational level (ρ = 0.373, p < 0.001), and MMSE score (ρ = 0.793, p < 0.001). The internal consistency of the CASI-S was high (α = 0.848) and the correlation between test and retest was 0.688, suggesting adequate temporal stability. In the ROC curve analyses, scores of 22/23 generated an area under the curve of 0.907, with sensitivity of 93% and specificity of 81%.Conclusions:The CASI-S can be useful for dementia screening in primary care in Brazil.

Effect of Growth Stage on Trifloxysulfuron and Glyphosate Efficacy in Twelve Weed Species of Citrus Groves

2004 ◽  
Vol 18 (4) ◽  
pp. 1031-1036 ◽  
Author(s):  
Samunder Singh ◽  
Megh Singh
Keyword(s):  
Growth Stage ◽  
Fresh Weight ◽  
Weed Species ◽  
Leaf Stage ◽  
Yellow Nutsedge ◽  
Redroot Pigweed ◽  
Citrus Groves ◽  
Prickly Sida ◽  
Test Plants

Efficacy of trifloxysulfuron with and without surfactant was evaluated against balsamapple, cat's claw vine, Florida beggarweed, hairy beggarticks, ivyleaf morningglory, johnsongrass, prickly sida, redroot pigweed, sicklepod, strangler vine, tall morningglory, and yellow nutsedge at 21, 42, and 63 g ai/ha applied at the four- or six-leaf stages and compared with glyphosate at 280, 560, and 840 g ae/ha. Delayed application from the four- to six-leaf stage significantly reduced trifloxysulfuron efficacy; reduction was less with glyphosate. Trifloxysulfuron plus 0.25% X-77 was more effective on the four-leaf stage than on the six-leaf stage plants of redroot pigweed, johnsongrass, hairy beggarticks, strangler vine, and prickly sida; effect was similar on yellow nutsedge, sicklepod, Florida beggarweed, balsamapple, ivyleaf morningglory, and tall morningglory. Trifloxysulfuron at 63 g/ha plus surfactant reduced the fresh weight of all test plants more than 80% compared with control, except prickly sida, strangler vine, and cat's claw vine. Glyphosate was less effective than trifloxysulfuron plus surfactant against tall morningglory, sicklepod, ivyleaf morningglory, and yellow nutsedge but was significantly better against balsamapple, prickly sida, and cat's claw vine. None of the herbicides provided satisfactory control of cat's claw vine, strangler vine, and prickly sida.

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