Effect of Nitrogen and Moisture Stress on Severity of Maize Dwarf Mosaic Virus Infection in Corn Seedlings. M. J. Vangessel, Former Graduate Research Assistant, Department of Crop Science, North Carolina State University, Raleigh 27695-7620. H. D. Coble, Professor, Department of Crop Science, North Carolina State University, Raleigh 27695-7620. Plant Dis. 77:489-491. Accepted for publication 4 January 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0489.

The impact of nitrogen and moisture stress on maize dwarf mosaic virus strain A (MDMV-A) in corn (Zea mays) was examined in a greenhouse experiment. The factors were MDMV-A, moisture, and nitrogen arranged in a factorial design, with each stress either present or absent. Moisture × nitrogen interaction was significant for number of leaves, plant height, and dry weight. MDMV × moisture was significant for dry weight. Ranking effect of stresses on MDMV titer, lowest to highest, was: adequate nitrogen and adequate moisture (no stress), and adequate nitrogen and inadequate moisture (moisture stress) < inadequate nitrogen and inadequate moisture (dual stress) < inadequate nitrogen and adequate moisture (nitrogen stress). Weeds that can increase moisture and nitrogen stress may need to have thresholds adjusted for cornfields in which the incidence of MDMV is high.