Basis for Increased Activity from Herbicide Combinations with Ethofumesate Applied on Sugarbeet (Beta vulgaris)

Weed Science ◽  
1982 ◽  
Vol 30 (2) ◽  
pp. 195-200 ◽  
Author(s):  
David N. Duncan ◽  
William F. Meggitt ◽  
Donald Penner
Keyword(s):  
Beta Vulgaris ◽  
Trichloroacetic Acid ◽  
Epicuticular Wax ◽  
Gas Liquid Chromatography ◽  
Wax Deposition ◽  
Foliar Absorption ◽  
Combination Treatments ◽  
Leaf Surfaces ◽  
Increased Activity ◽  
Long Chain

Differences in susceptibility of sugarbeet (Beta vulgarisL.) to preemergence application of ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate], pyrazon [5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone], and TCA (trichloroacetic acid) were evaluated in several combination treatments. Exposure of plants to ethofumesate severely decreased epicuticular wax deposition on leaf surfaces. Separation of epicuticular wax into major components by gas-liquid chromatography indicated that ethofumesate decreased deposition of alkanes andsec-ketones, but increased the percentage of long-chain waxy esters. TCA also decreased deposition of alkane and ketone components, but not of waxy esters. Waxes were unaffected by pyrazon. Greater foliar absorption of14C-ethofumesate,14C-desmedipham [ethylm-hydroxycarbanilate carbanilate (ester)], and14C-ethofumesate +14C-desmedipham was observed in plants that received preemergence treatments of ethofumesate plus TCA compared to pyrazon or a control.

scholarly journals Variation of hydrocarbon constituents of epicuticular wax of leaves of Litchi chinensis Sonn.

2013 ◽  
Vol 31 (1) ◽  
pp. 73 ◽  
Author(s):  
Titil Datta Samanta ◽  
Tithi Ghosh ◽  
Subrata Laskar
Keyword(s):  
Epicuticular Wax ◽  
Gas Liquid Chromatography ◽  
Electron Microscopic ◽  
Litchi Chinensis ◽  
Hydrocarbon Content ◽  
Fruiting Stage ◽  
Scanning Electron Microscopic ◽  
Layer Chromatography ◽  
Long Chain ◽  
Scanning Electron

Epicuticular wax of leaves of Litchi (Litchi chinensis Sonn.) collected all through the year and n-alkane extract was analysed by thin layer chromatography, infrared spectroscopy and gas liquid chromatography, using standard hydrocarbons. Twenty long chain hydrocarbons (n-C16 to n-C35) were identified and quantified. Distinct variation of hydrocarbon content has been observed during different time of the year. Scanning electron microscopic views of total epicuticular wax, hydrocarbon and upper surface of Litchi chinensis Sonn. leaf during the fruiting stage of the tree has also been done.

Epicuticular Wax on Johnsongrass (Sorghum halepense) Leaves

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Chester G. Mcwhorter
Keyword(s):  
Drought Stress ◽  
Relative Humidity ◽  
Leaf Blade ◽  
Unit Area ◽  
Grain Sorghum ◽  
Epicuticular Wax ◽  
Sorghum Halepense ◽  
Wax Deposition ◽  
Narrow Side ◽  
Leaf Surfaces

Studies were conducted to investigate the uniformity of epicuticular wax deposition on leaf blades of johnsongrass. Johnsongrass leaves grown under drought stress had greatly increased epicuticular wax weights compared to leaves from plants with adequate moisture, but relative humidity (95% vs. 40 ± 5%) had little effect on wax deposition. Wax weights decreased as leaves matured. Sections of lower leaf surfaces of young johnsongrass leaves tended to have more wax than sections of upper leaf surfaces, but weights were nearly equal on upper vs. lower leaf surfaces of older leaves. The narrow side of asymmetrical johnsongrass leaf blades often had more wax per unit area than the wide side. The area over the midvein contained more wax per unit area than either the narrow or wide side of the leaf blade. Greatest wax concentrations on individual leaves were over the midvein area near the leaf apex. Leaf blades of johnsongrass had more wax per unit area than leaves of corn or grain sorghum.

Postemergence Activity of Sulfentrazone: Effects of Surfactants and Leaf Surfaces

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 797-803 ◽  
Author(s):  
Franck E. Dayan ◽  
Hannah M. Green ◽  
John D. Weete ◽  
H. Gary Hancock
Keyword(s):  
Inverse Relationship ◽  
Cuticular Wax ◽  
Severely Injured ◽  
Foliar Injury ◽  
Foliar Absorption ◽  
Yellow Nutsedge ◽  
Soybean Cultivars ◽  
Leaf Surfaces ◽  
Cellular Tolerance ◽  
Species Specific

Sulfentrazone was foliar applied at 34 and 56 g ai ha−1alone or in combination with surfactants to soybean cultivars Hutcheson and Centennial and to sicklepod, coffee senna, smallflower morningglory, velvetleaf, and yellow nutsedge. The most sensitive weeds, including coffee senna, smallflower morningglory, and velvetleaf, were severely injured by the lowest rate when sulfentrazone was applied with surfactants. Sulfentrazone provided the highest control of yellow nutsedge with X-77. Soybeans were not severely injured by sulfentrazone applied alone, but 55% foliar injury occurred when the herbicide was applied with X-77. However, the seedlings were not killed. Sicklepod was the most tolerant of the weeds tested. In the absence of surfactants, the order of radiolabeled sulfentrazone absorption by the foliage was Centennial (5.8%) = Hutcheson (8.5%) = coffee senna (10.4%) < yellow nutsedge (17.0%) < velvetleaf (22.3%) = smallflower morningglory (24%). Sicklepod leaves did not retain droplets containing sulfentrazone when no surfactant was used. Species with the highest foliar absorption also showed the greatest phytotoxic response to the herbicide. Addition of surfactants to the spray mixture enhanced the foliar absorption and overall phytotoxicity of sulfentrazone in the weeds. An inverse relationship was detected between the foliar absorption of sulfentrazone without surfactants and the amount of cuticular wax present on the leaves. No such correlation was observed when surfactants were used. Thus, surfactants overcame the barrier to absorption imposed by the cuticular wax and, under these conditions, selectivity apparently became dependent upon species-specific cellular tolerance to sulfentrazone.

Vapor Pressures of Low-Volatile Esters of 2,4-D

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 541-544 ◽  
Author(s):  
G. W. Flint ◽  
J. J. Alexander ◽  
O. P. Funderburk
Keyword(s):  
Dichlorophenoxyacetic Acid ◽  
Gas Liquid Chromatography ◽  
Vapor Pressures ◽  
Butyl Ether ◽  
Ether Linkage ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Hydrocarbon Alcohols ◽  
Long Chain ◽  
Volatile Esters ◽  
Chain Hydrocarbon

The vapor pressures of the four most common commercial low-volatile esters and a reference high-volatile ester of 2,4-dichlorophenoxyacetic acid (2,4-D) were determined by gas-liquid chromatography. The order of increasing volatility and the vapor pressure of these esters in mm of Hg at 187 C are as follows: isooctyl—2.7; 2-ethylhexyl—3.0; butoxy ethanol—3.9; propylene glycol butyl ether—3.9; and the reference, isopropyl—16.7. Extrapolations to 25 C support this ranking at working temperatures. Commercial esters of 2,4-D derived from long-chain hydrocarbon alcohols are in the same volatility range as the commercial esters containing an ether linkage.

Environmental Effects on Velvetleaf (Abutilon theophrasti) Epicuticular Wax Deposition and Herbicide Absorption

Weed Science ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 14-21 ◽  
Author(s):  
H. Hatterman-Valenti ◽  
A. Pitty ◽  
M. Owen
Keyword(s):  
Drought Stress ◽  
Light Intensity ◽  
Secondary Alcohol ◽  
Field Capacity ◽  
High Light Intensity ◽  
Epicuticular Wax ◽  
High Light ◽  
Wax Deposition ◽  
Low Light ◽  
Stress Regime

Controlled environment experiments showed that velvetleaf plants grown under drought stress or low temperature (LT) treatments had greater leaf epicuticular wax (ECW) deposition compared to plants grown in soil with moisture at field capacity (FC) or a high temperature (HT) regime. Light intensity did not affect ECW deposition; however, increasing light intensity decreased the leaf ECW ester content and increased the secondary alcohol content. Plants grown at an LT regime or under FC had leaf ECW with fewer hydrocarbons and more esters than those grown at an HT or drought stress regime. Velvetleaf absorption of acifluorfen increased as light intensity decreased for plants grown in adequate soil water content, while the opposite was true for drought-stressed plants. Velvetleaf absorption of acifluorfen was approximately 3 and 10 times greater, respectively, with the addition of 28% urea ammonium nitrate (UAN) in comparison to crop oil concentrate (COC) or no adjuvant, regardless of the environmental treatments. Plants absorbed more acifluorfen when subjected to the LT regime in comparison to the HT regime when UAN was the adjuvant, while the opposite was true when COC was the adjuvant. Velvetleaf absorption of acifluorfen was not affected by drought stress when COC or no adjuvant was used and varied between studies when UAN was used. Velvetleaf absorption of bentazon was greatest for plants grown under HT/FC or high light/FC treatments and least with plants grown under HT/drought stress or low light/drought stress treatments, regardless of the adjuvant. However, bentazon absorption was higher with the addition of an adjuvant and for plants grown at a high light intensity or FC condition compared with medium to low light intensity or drought stress treatments.

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