Discovery of a Common Purslane (Portulaca oleracea) Biotype Resistant to Linuron

1999 ◽  
Vol 13 (3) ◽  
pp. 599-605 ◽  
Author(s):  
Joseph G. Masabni ◽  
Bernard H. Zandstra
Keyword(s):  
Daucus Carota ◽  
Field Experiments ◽  
Portulaca Oleracea ◽  
Resistance Ratio ◽  
Cross Resistance ◽  
Preliminary Evaluation ◽  
Low Level ◽  
Greenhouse Experiments ◽  
Test Kit ◽  
Common Purslane

Greenhouse and field experiments were conducted to confirm and quantify linuron resistance in common purslane (Portulaca oleracea) collected from a carrot (Daucus carota) field in Imlay City, MI. Preliminary evaluation was made using a flotation test kit to identify resistance to linuron and atrazine. Subsequent greenhouse experiments indicated that this common purslane was resistant to 11.2 kg/ha linuron and 179 kg/ha atrazine. The resistance ratio for linuron was > 300 and was > 400 for atrazine. The resistant common purslane was also highly resistant to diuron, cyanazine, and prometryn but had a low level of negative cross-resistance to bromoxynil. Both resistant and susceptible biotypes of common purslane were sensitive to hexazinone and bentazon.

Weed Control and Tolerance of Sulfonylurea Herbicides in Caladium

2018 ◽  
Vol 32 (4) ◽  
pp. 424-430 ◽  
Author(s):  
Jialin Yu ◽  
Nathan S. Boyd
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Tuber Weight ◽  
Sulfonylurea Herbicides ◽  
Greenhouse Experiments ◽  
Tuber Injury ◽  
Herbicide Treatments ◽  
Sequential Treatments ◽  
Common Purslane ◽  
Hand Weeding

AbstractControl of broadleaf weeds in caladium is difficult due in part to a lack of selective POST herbicides. Cultivation is not an option due to the dense canopy and potential for tuber injury. As a result, growers currently rely on preemergence (PRE) herbicide and hand-weeding. The objective of this research was to evaluate the control of four common broadleaf weeds of field grown caladium with POST applications of halosulfuron, thifensulfuron-methyl, and trifloxysulfuron, and determine the tolerance of caladium cultivars ‘Florida Fantasy’ and ‘Florida cardinal’ to POST applications of halosulfuron. At 4 weeks after treatment (WAT), thifensufluron-methyl at 28 g ai ha−1 and trifloxysulfuron at 84 g ai ha−1 provided approximately 90 and 70% common purslane control, respectively, while halosulfuron at 210 g ai ha−1 provided 55% suppression. Trifloxysulfuron controlled ≥90% spotted spurge at 42 g ha−1, whereas the highest rate of halosulfuron and thifensulfuron-methyl only achieved 60% suppression. In field experiments, the evaluated sulfonylurea (SU) herbicides were less efficacious on hairy indigo and sharppod morningglory as control never exceeded 65 and 50%, respectively. In greenhouse experiments, the evaluated halosulfuron rates ranging from 26 to 420 g ha−1 did not significantly reduce caladium tuber weight from the nontreated control. Averaged over halosulfuron rates, ‘Florida Fantasy’ damage was 5 and 6% at 2 and 4 WAT, respectively, while ‘Florida Cardinal’ damage was 11%. We conclude that none of the herbicide treatments effectively controlled all species evaluated. Sequential treatments, higher rates, or tank-mixtures may be necessary to adequately control these species. We also conclude that caladium cultivars ‘Florida Fantasy’ and ‘Florida Cardinal’ have acceptable tolerance to POST applications of halosulfuron. Further research is needed to evaluate caladium tolerance to other SU herbicides.

Selectivity, Movement, and Persistence of Soil-Incorporated Herbicides in Carrot Plantings

Weed Science ◽  
1970 ◽  
Vol 18 (2) ◽  
pp. 247-252 ◽  
Author(s):  
R. M. Menges ◽  
J. L. Hubbard
Keyword(s):  
Biological Activity ◽  
High Temperatures ◽  
Daucus Carota ◽  
Half Life ◽  
Field Experiments ◽  
Amaranthus Retroflexus ◽  
Amaranthus Palmeri ◽  
Soil Temperatures ◽  
Common Purslane ◽  
Liquid Chromatographic

The comparative performances of several herbicides incorporated 2.5 cm deep and unincorporated in furrow-irrigated soil were studied in four field experiments. Among eight herbicides evaluated,a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) was the most effective herbicide and controlled redroot pigweed (Amaranthus retroflexusL.), Palmer amaranth (Amaranthus palmeriS. Wats.), common purslane (Portulaca oleraceaL.), and barnyardgrass (Echinochloa crusgalli(L.) Beauv.) when incorporated, without reduction of yield in carrots (Daucus carotaL., var.saliva, cv. Long Imperator). Trifluralin andO,O-diisopropyl phosphorodithioateSester withN-(2-mercaptoethyl)benzenesulfonamide (bensulide) gave consistently good results in all years although soil temperatures and evaporative losses of water were variable. Bioassays indicated and gas-liquid chromatographic (hereinafter referred to as GLC) assays confirmed that rainfall moved bensulide and trifluralin 2.5 cm downward in soil, and that dimethyl tetrachloroterephthalate (DCPA) was not moved below the original depth of incorporation in soil. GLC assays were most sensitive but generally agreed with bioassays of trifluralin-treated soils. Under high temperatures, infrequent rainfall, and furrow irrigation, the half-life of DCPA and trifluralin activities was 3 weeks, with no biological activity after 7 months. The half-life of bensulide activity was 6 months, with no biological activity after 22 months.

Negative cross resistance of Spodoptera litura Fabricius population of tomato to newer molecule spinetoram

ENTOMON ◽  
2019 ◽  
Vol 44 (2) ◽  
pp. 127-132
Author(s):  
M. Visnupriya ◽  
N. Muthukrishnan
Keyword(s):  
Spodoptera Litura ◽  
Laboratory Strain ◽  
Field Population ◽  
Resistance Ratio ◽  
Cross Resistance ◽  
In Vivo Toxicity

Field population of Spodoptera litura from tomato ( resistant to the majority of the conventional insecticide molecules) were subjected to the in vivo toxicity of spinetoram 12 SC to assess whether cross resistance exists or not. Untreated larvae of both field and laboratory strains showed no mortality during 48 hours of feeding. After 48 hours of feeding on spinetoram 12 SC treated leaves, LC50s of field larvae were 0.28, 0.93, 3.71 and 7.11 ppm for the 2nd, 3rd, 4th and 5th instars of S. litura respectively. However, in the laboratory strain these values were 1.12, 5.86, 36.72 and 91.55 ppm for 2nd, 3rd, 4th and 5th instars of S. litura respectively. Resistance ratio was 0.25, 0.16, 0.10 and 0.08 for the 2nd instar up to the 5th instar of S. litura.

EFFECTS OF SOIL ACIDITY ON RHIZOBIA NUMBERS, NODULATION AND NITROGEN FIXATION BY ALFALFA AND RED CLOVER

1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG
Keyword(s):  
Nitrogen Fixation ◽  
Soil Ph ◽  
Soil Acidity ◽  
Field Experiments ◽  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Red Clover ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Greenhouse Experiments

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.

Effects of potassium and sodium application to soil on growth and cation accumulation of herbage

1984 ◽  
Vol 35 (1) ◽  
pp. 85 ◽  
Author(s):  
GN Mundy
Keyword(s):  
Plant Tissue ◽  
Field Experiments ◽  
Equivalent Amount ◽  
Growth Responses ◽  
K Uptake ◽  
Low Level ◽  
Pasture Plants

The effects of potassium (K) and sodium (Na) applications to soil on growth and cation accumulation of herbage were investigated in pot and field experiments. The application of K to K-deficient soil was more efficient at increasing growth than was the application of Na; however, at suboptimal K availability, yield was increased by Na application. Growth responses to Na were restricted when the soil contained insufficient K to satisfy the minimum K requirement of pasture plants. The Na concentration of herbage was markedly reduced by K applications, whereas Na had little effect on K uptake. It was found that an application of Na to soil containing a low level of Na raised the Na concentration of herbage sufficiently to satisfy animal needs. Both K and Na reduced the calcium (Ca) and magnesium (Mg) concentration of herbage, although Na was less inhibitive than an equivalent amount of K. The decline in Ca and Mg in plant tissue with increasing concentrations of soil K and Na was exponential and, as the decline approached the asymptotic concentration, further increases in soil K and Na had only a small effect on Ca and Mg uptake. The implications of these findings are discussed.

Interaction of Bentazon and Imazethapyr Applied Postemergence to Nutsedge (Cyperus spp.)

1995 ◽  
Vol 22 (2) ◽  
pp. 150-154
Author(s):  
Alan C. York ◽  
John W. Wilcut
Keyword(s):  
Ammonium Salt ◽  
Sodium Salt ◽  
Field Experiments ◽  
Pyridinecarboxylic Acid ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Greenhouse Experiments

Abstract Field and greenhouse experiments evaluated purple nutsedge (Cyperus rotundas L.) and yellow nutsedge (C. esculentus L.) control with mixtures of bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] and imazethapyr {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid} applied postemergence. Mixtures of the sodium salt of bentazon at 0.6 or 1.1 kg ae/ha and the ammonium salt of imazethapyr at 35 or 70 g ae/ha were antagonistic on purple nutsedge in field and greenhouse experiments. Mixtures of bentazon at 0.6 kg/ha and imazethapyr at 35 or 70 g/ha were additive on yellow nutsedge in field experiments but antagonistic in greenhouse experiments. Mixtures of bentazon at 1.1 kg/ha and imazethapyr at 35 or 70 g/ha were antagonistic on yellow nutsedge in field and greenhouse experiments.

Herbicide-Crop Rotation for Johnsongrass (Sorghum halepense) Control

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 479-485 ◽  
Author(s):  
J. E. Dale ◽  
J. M. Chandler
Keyword(s):  
Crop Rotation ◽  
Field Experiments ◽  
Amaranthus Retroflexus ◽  
Cyperus Rotundus ◽  
Sorghum Halepense ◽  
Purple Nutsedge ◽  
Cropping Sequence ◽  
Sesbania Exaltata ◽  
Common Purslane ◽  
Sida Spinosa

The feasibility of herbicide and crop rotation for the control of johnsongrass [Sorghum halepense(L.) Pers.] in corn (Zea maysL.) was studied in field experiments. Light infestations of johnsongrass were initially present, but it became the predominant weed after 4 yr of continuous corn treated with atrazine [2-chloro-4-(ethylamino)-6-(isopropylamine)-s-triazine], cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl]amino]-2-methylpropionitrile}, and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], alone and in combinations at rates of 2.24, 2.24, and 0.84 kg/ha, respectively. The infestation of johnsongrass was effectively controlled by growing corn in rotation with cotton (Gossypium hirsutumL.) in a cropping sequence of corn-cotton-cotton-corn, in which trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] and MSMA (monosodium methanearsonate) at 0.56, 2.24, and 2.24 kg/ha respectively, were used for weed control in cotton. In the corn-cotton-cotton-corn cropping sequence, the herbicide treatments also prevented increases in the populations of other indigeneous weeds including prickly sida (Sida spinosaL.), prostrate spurge (Euphorbia supinaRaf.), spotted spurge (Euphorbia maculataL.), common purslane (Portulaca oleraceaL.), tall morningglory [Ipomoea purpurea(L.) Roth], common cocklebur (Xanthium pensylvanicumWallr.), spurred anoda[Anoda cristata(L.) Schlecht.], hemp sesbania [Sesbania exaltata(Raf.) Cory], redroot pigweed (Amaranthus retroflexusL.), goosegrass [Eleusine indica(L.) Gaertn.], junglerice [Echinochloa colonum(L.) Link], large crabgrass [Digitaria sanguinalis(L.) Scop.], and purple nutsedge (Cyperus rotundusL.).

A Preliminary Evaluation of a Prototype Western Blot Confirmatory Test Kit for Syphilis

1994 ◽  
Vol 5 (6) ◽  
pp. 409-414 ◽  
Author(s):  
H Young ◽  
P J Walker ◽  
D Merry ◽  
A Mifsud
Keyword(s):  
Western Blot ◽  
False Positive ◽  
High Sensitivity ◽  
High Specificity ◽  
Confirmatory Test ◽  
Preliminary Evaluation ◽  
Serological Tests ◽  
Western Blot Test ◽  
Specificity And Sensitivity ◽  
Test Kit

A prototype Western blot kit was evaluated as a confirmatory test for syphilis using 131 sera characterized by other serological tests for syphilis. There were 114 treponemal sera (including 94 cases of early syphilis, 83 of which were untreated) and 17 non-treponemal problem sera (11 gave false positive reactions on screening with the TmpA recombinant antigen enzyme immunoassay (EIA), 3 gave false positive fluorescent treponemal antibody absorbed (FTA-abs) tests, and 3 false positive Captia Syphilis G EIA results). Based on the manufacturer's criteria of reactivity in multiple bands for designating a positive result the Western blot test gave a sensitivity of 99.1% (113/114) and a specificity of 88.2% (15/17) when indeterminate reactions were scored positive and 98.2% (112/114) and 100% (17/17) when indeterminate reactions were scored negative. Sensitivity was high in both treated and untreated infection. Corresponding sensitivities for the TPHA and FTA-abs when equivocal reactions were scored negative were 97.5% (111/114) and 99.1% (113/114). The high sensitivity of the FTA-abs in this study is probably due to the large number of untreated primary infections. Our results with the Western blot, confirm earlier studies using ‘in-house’ test systems and, support a role for a commercial Western blot test in the confirmatory diagnosis of syphilis. Further studies are required to confirm the high specificity and sensitivity of the kit in a larger series including a wider variety of non-treponemal cases as well as patients with untreated and treated infection.

Diabrotica adelpha Harold1 and Diabrotica balteata LeConte1 Feeding on Common Purslane (Portulaca oleracea L.) at Tamaulipas, México

2021 ◽  
Vol 45 (4) ◽  
Author(s):  
Jorge Ariel Torres-Castillo ◽  
Eduardo Padrón-Torres ◽  
Leonardo Uriel Arellano-Méndez ◽  
Miguel Ángel García-Delgado ◽  
Reyna Ivonne Torres-Acosta
Keyword(s):  
Portulaca Oleracea ◽  
Diabrotica Balteata ◽  
Common Purslane
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