The effects of adjuvents upon the pesticide uptake and penetration of foliage
type: CreativeWork
description: The foliar uptake by wheat of the wild oat herbicide flampropmethyl has been studied following application of ul droplets of an aqueous solution. The results show that over the time required for the drop to dry the compound does not partition into the surface waxes and crystallises as an external deposit. This deposit is stable to volatilization and photochemical and biochemical degradation, and is depleted by foliar penetration. Adsorbtion by the leaf surface wax is initially rapid and thereafter occurs at a relatively constant rate until the almost complete exhaustion of the surface deposit. Penetration of the epicuticular wax layer generally proceeds at a slower rate than does adsorption of the surface deposit and the herbicide is accumulated in the wax layer. The compound is lost from the epicuticular waxes only slowly to the leaf tissues. Movement within the leaf tissues away from the area of uptake is predominantly acropetal to the leaf tip and it is presumed that the compound moves with the transpiration stream. A similar fate befalls the compound when aqueous solutions of flamprop-methyl are applied as ul droplets to barley or wild oat, no evidence of selectivity between wheat, barley and wild oat as a consequence of preferential uptake was found. Foliar uptake of flamprop-methyl is shown to depend on the amount of compound applied to un1 t area of leaf surface and to increase as the amount applied is increased or as the area to which application is made is increased. These trends are discussed in terms of compartmental model of foliar uptake. Foliar uptake of flamprop-methyl is also shown to be slightly influenced by environmental factors; in an environment in which maximum daily temperatures exceeded 35 o C penetration was especially rapid and tended to completion within 24 hours. The surface properties of aqueous solutions of selected polyoxyethylene non-ionic surfactants have been studied prior to investigating the effect of these compounds on the foliar…
abstract: The foliar uptake by wheat of the wild oat herbicide flampropmethyl has been studied following application of ul droplets of an aqueous solution. The results show that over the time required for the drop to dry the compound does not partition into the surface waxes and crystallises as an external deposit. This deposit is stable to volatilization and photochemical and biochemical degradation, and is depleted by foliar penetration. Adsorbtion by the leaf surface wax is initially rapid and thereafter occurs at a relatively constant rate until the almost complete exhaustion of the surface deposit. Penetration of the epicuticular wax layer generally proceeds at a slower rate than does adsorption of the surface deposit and the herbicide is accumulated in the wax layer. The compound is lost from the epicuticular waxes only slowly to the leaf tissues. Movement within the leaf tissues away from the area of uptake is predominantly acropetal to the leaf tip and it is presumed that the compound moves with the transpiration stream. A similar fate befalls the compound when aqueous solutions of flamprop-methyl are applied as ul droplets to barley or wild oat, no evidence of selectivity between wheat, barley and wild oat as a consequence of preferential uptake was found. Foliar uptake of flamprop-methyl is shown to depend on the amount of compound applied to un1 t area of leaf surface and to increase as the amount applied is increased or as the area to which application is made is increased. These trends are discussed in terms of compartmental model of foliar uptake. Foliar uptake of flamprop-methyl is also shown to be slightly influenced by environmental factors; in an environment in which maximum daily temperatures exceeded 35 o C penetration was especially rapid and tended to completion within 24 hours. The surface properties of aqueous solutions of selected polyoxyethylene non-ionic surfactants have been studied prior to investigating the effect of these compounds on the foliar…
author: McCann, AW
keywords: GE Environmental Sciences, QH Natural history, QK Botany
date published: 1982-01
date modified: 2026-07-24T06:30:06Z
provider: Liverpool Jon Moores University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Liverpool John Moores University

PropertyValue
property ID: DOI
value: 10.24377/LJMU.t.00004981