Abstract

St. Augustinegrass (Stenotaphrum secundatum) was evaluated in field plots and pots for susceptibility to Pyricularia grisea, the causal organism of gray leaf spot.  In the presence of repeated natural infestations, disease severity was moderately consistent (r=0.41-0.73) among genotypes.  High susceptibility was localized in blue-green triploid genotypes such as cultivars Bitterblue and Floratine and in certain collections from the U.S. Gulf Coast.  Roselawn and two African introductions of S. dimidiatum were highly resistant.