Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/20/1997
Publication Date: N/A
Technical Abstract: The effect of seedling infection by Monosporascus cannonballus, a causal agent of root rot/vine decline of muskmelon, on root growth of three muskmelon cultivars ( Magnum 45', Mission' and Primo') were investigated in a field experiment at Kingsville, Texas. Root growth and disease development were monitored at different stages of maturity throughout the experiment. The characteristic discrete brownish and necrotic lesions of M. cannonballus were apparent on the taproots of all inoculated cultivars and on distal lateral roots of Magnum 45'. Root disease severities ranges from 1.3 to 2.6 for Primo' 2.0 to 3.1 for Mission' and 2.0 to 3.5 for Magnum'. Perithecia of M. cannonballus were observed on roots of all inoculated plants and not on the roots of non-inoculated plants. While the main taproots and lateral roots grew better in control plants, the diameters of the taproots, 3-cm below the crown, were significantly larger in inoculated plants as compared to the control plants. The apparent increase in the taproot diameters may be a result of pruning effect of M. cannonballus on muskmelon roots.