Low-temperature Scanning Electron Microscopy and Physical-Chemical investigations of leaf surface characteristics

Abstract

Plant protection agents (often incorrectly referred to as ‘pesticides’) mostly are targeted at plant surfaces either to protect them against pathogens and parasites or to destroy the treated plants in the case of herbicides. Many times, more than one species of plants are involved, that respond differently to such applications.In any of the cases cited, a thorough knowledge of the leaf surface characteristics may help to explain desired or undesirable effects. Also the wetting properties of a spray applied to plants will likely influence the performance of the active ingredient involved. It is obvious that only the use of a whole array of different methods will allow an interpretation or a prediction of effects caused by the application of plant protection sprays.To get well preserved epicuticular wax structures of leaf surfaces we used low-temperature scanning electron microscopy (LTSEM). Fresh cut samples were immediatly frozen in liquid nitrogen, transferred into a Balzers SCU 020 cryopreparation unit attached to an SEM Cambridge Mk II A.