VIEW ARTICLE

Aerial Detection of Maize Dwarf Mosaic Virus-Diseased Corn. Beverly S. Ausmus, Assistant in Agricultural Biology, Department of Agricultural Biology, University of Tennessee Agricultural Experiment Station, Knoxville 37916; James W. Hilty, Associate Professor of Plant Pathology, Department of Agricultural Biology, University of Tennessee Agricultural Experiment Station, Knoxville 37916. Phytopathology 62:1070-1074. Accepted for publication 3 April 1972. DOI: 10.1094/Phyto-62-1070.

Maize dwarf mosaic virus (MDMV) was detected in corn, and severity estimates were made using aerial photographic techniques. Two ground truth sites in Tennessee were photographed periodically from a remote platform during growing seasons of 1969 and 1970. Photographic imagery using: Kodak panchromatic, type 8401; Ektachrome aerial color, type 2448; Ektachrome Aero Infrared, type 8443; and Kodak Infrared Aerographic, type 5424 was obtained from a cluster of four 70-mm Hasselblad cameras. Automated data analysis of imagery yielded density signatures of healthy and diseased corn, and was accomplished using a microdensitometer and digital computer. Computer-drawn histograms supplied counts of density points per density range allowing calculation of percentages of each disease rating as a function of the total area scanned by the microdensitometer. MDMV-diseased corn was detected using all four emulsions in late season, but with infrared imagery only prior to peak symptom development. The order of preference of emulsions for MDMV detection was: type 8443, type 5424, type 2448, and type 8401. Disease severity ratings were assigned accurately and rapidly using these techniques.