title: Retention and rainfastness of mancozeb as affected by physicochemical characteristics of adaxial apple leaf surface after enhanced UV-B radiation.
abstract: It is not clear so far whether alteration of leaf micromorphology and surface wax chemistry due to the impact of environmental factors, such as UV-B radiation, affects retention and rainfastness of applied pesticide solutions. In this study; UV-B treated and untreated adaxial leaf surfaces of apple seedlings (Malus domestica Borkh.) were characterized in terms of chemical composition, micromorphological fine structure, hydrophobicity, and wettability. Furthermore, the retention and rainfastness of applied fungicide mancozeb were studied. The samples were examined 0, 24 and 48 h after ultraviolet (UV)-B radiation (0.022 kW m(-2) for 150 min) The total wax mass, recovered from the adaxial leaf surface, amounted from 0.38 microg cm(-2) (control) up to 0.49 microg cm(-2) (24 h). Chemical composition of surface wax altered, whereas the contact angle of applied water droplets on leaf surface of UV-B treated plants did not change significantly compared to the control. The alteration of surface wax quantity and quality significantly affected retention of a.i.; it increased at a sampling time of 24 h after UV-B irradiation, whereas rainfastness of the fungicide spray solution was not significantly influenced.
authors: Institute of Crop Science and Resource Conservation, Horticultural Sciences, University of Bonn, Bonn, Germany. kbringe@hotmail.com
authors: Katja
authors: K
authors: Bringe
authors: Mauricio
authors: M
authors: Hunsche
authors: Michaela
authors: M
authors: Schmitz-Eiberger
authors: Georg
authors: G
authors: Noga
mesh_terms: D018556:Crops, Agricultural / Q000737:chemistry* / Q000648:ultrastructure; D005659:Fungicides, Industrial / Q000032:analysis*; D027845:Malus / Q000737:chemistry* / Q000648:ultrastructure; D008344:Maneb / Q000032:analysis*; D019441:Plant Epidermis / Q000737:chemistry / Q000648:ultrastructure; D018515:Plant Leaves / Q000737:chemistry / Q000502:physiology*; D011891:Rain; D036226:Seedlings; D013997:Time Factors; D014466:Ultraviolet Rays; D014885:Waxes / Q000737:chemistry; D015038:Zineb / Q000032:analysis*
chemical_list: D005659:Fungicides, Industrial; D014885:Waxes; D008344:Maneb; C013099:mancozeb; D015038:Zineb