UPTAKE OF PICLORAM BY EUCALYPT LEAF DISCS

Abstract

S ummary Uptake of picloram by upper and lower surfaces of Eucalyptus viminalis juvenile leaves in light and dark, and measurements of stomatal resistances, were consistent with a major role of stomata in uptake. Uptake of picloram and stomatal resistances of E. viminalis and E. polyanthemos leaf discs measured under varying experimental conditions also suggested a major role for stomata in uptake. This is discussed in terms of leaf surface characteristics and wettability. Some premises on which arguments denying stomatal penetration of herbicides are based are examined, and concluded to be false.