Effect of Temperature and Relative Humidity on Translocation of¹⁴C-Metriflufen in Johnsongrass (Sorghum halepense) and Soybean (Glycine max)

Abstract

Absorption and translocation of14C-metriflufen {2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} in johnsongrass [Sorghum halepense(L.) Pers.] and soybean [Glycine max(L.) Merr. ‘Lee 68’] were evaluated under different environmental conditions. At 40% relative humidity (RH), an increase in air temperature from 18 to 35 C increased translocation of the14C in johnsongrass more than four-fold following application of14C-metriflufen to an area on the third leaf. At 100% RH, translocation of the14C was twice as great at 27 C as at 18 C, but translocation at 35 C was intermediate. In the combined analysis, translocation in johnsongrass was no better at 100% RH than at 40% RH. Regardless of level of RH, most translocation in johnsongrass at 18 and 27 C was toward the distal half of the treated leaf, but at 35 C most translocation was toward the proximal half of the treated leaf. Translocation of14C in soybeans increased more than four-fold as air temperature was increased from 18 C to 35 C, and more translocation occurred at 100% RH than at 40% RH at 18, 27, and 35 C. More than 80% of the14C-metriflufen remained in the treated leaf or on the surface of treated soybean leaves 48 h after application. More of the applied radioactivity was recovered from soybean plants than from johnsongrass plants.

Absorption and translocation of MON 37500 in wheat and other grass species

“…The pubescence on the leaf surface of downy brome may be one reason why temperature did not affect MON 37500 absorption. Other research also has reported that air temperatures affect foliar herbicide absorption dif- ferently in various plant species (AI-Khatib et al 1992b;McWhorter 1981). These differences can be attributed to variations in cuticle viscosity and cuticular wax, which occur when plants are exposed to different temperatures (Wanamarta and Penner 1989); however, interactions among plant species, environment, and herbicide are difficult to predict (Devine et al 1993).…”

Adjuvant Effects on Absorption, Translocation, and Metabolism of Haloxyfop-Methyl in Corn (Zea mays)

“…# SORHA] increased with addition of a nonionic surfactant to the spray solution at 24 C and 40% RH, but not at 24 C and 100% RH. Data from a second experiment by the same author (16) indi cated that translocation of 14 C-metriflufen applied to johnsongrass in a solution containing a nonionic surfactant was greater with 100% RH than with 40% RH at temperatures of 18 and 27 C. However, translocation of 14 C with 40% RH was equivalent to that with 100% RH at 35 C.…”

“…Haloxyfop is a recently developed postemergence herbi cide that selectively controls gramineous weeds in broadleaf crops (9). Haloxyfop and a number of related grass-specific herbicides contain the p-oxy phenoxy propanoate moiety as a structural component and show similar patterns of foliar absorption and translocation in susceptible plants (2,4,13,14,16,22). Studies with the butyl ester of 14 (2,4,13,14,22).…”

Absorption, Translocation, and Activity of Fluazifop-Butyl as Influenced by Plant Growth Stage and Environment

“…Successful chemical control of quackgrass requires that the biologically active compound is absorbed by the plant and translocated to the underground perennial tissue in sufficient concentration to cause death (12). Translocation has been observed with selective postemergence grass herbicides including diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy]propanoate} (1), sethoxydim {2- [1-(ethyloxyimino)butyl] -5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-l-one} (2), and the methyl ester of metriflufen {2-[4-(4-trifluoromethyl)phenoxy)phenoxy] propanoate} (9).…”