The effects of Maize Dwarf Mosaic Virus (MDMV) on different corn hybrids (Zea mays L.)

Abstract

A study was conducted to determine the effects of Maize Dwarf Mosaic Virus (MDMV) on different agronomic and grain quality characteristics of 106 corn hybrids. A randomized split-plot design with 3 replications was used. The virus isolate obtained from infected johnsongrass plants was mechanical inoculated by the use of the artist's airbrush procedure in the 3 to 5 leaf stage of growth. Disease severity index (DSI) reading were recorded of each hybrid as 1=healthy, 2=moderate mosaic, 3=severe mosaic, and 4=very severe mosaic symptoms. The data recorded to estimate the vulnerability of the selected series of corn hybrids was: days to silk, plant height, ear height, ear weight, and grain yield, it was analyzed using the SAS computer program. Test weight, hardness, density and pericarp removal were estimated to evaluate the effects of MDMV on the grain quality, these data was analyzed using overall mean comparisons. Mechanical inoculation with MDMV was successful; 29 hybrids had a severity index of 4, 40 had a rating value of 3, 17 hybrids showed a severity index rating of 2 and 20 had a rating value of 1. MDMV did not produce significant effects on the variable-days to silk, however plant and ear heights as well as ear weight and grain yield were reduced significantly. The variable test weight was not affected by MDMV. No effect was found on hardness and density. Pericarp removal was affected by MDMV.