WIDESPREAD OCCURRENCE OF CENTIPEDEGRASS MOSAIC IN SOUTH-CAROLINA

Isolates of panicum mosaic virus (PMV) cause St. Augustinegrass decline disease (SADD) and centipedegrass mosaic disease (CGMD). SADD is widespread in Texas and occurs in scattered locations in Louisiana, Arkansas, and Mississippi. CGMD was first observed in Louisiana in 1984 but subsequent reports have been rare. Over a 2-yr period, CGMD was found in numerous lawns in 12 counties throughout South Carolina and in at least one location in Georgia, northern Louisiana, Mississippi, and North Carolina. SADD was detected in only two counties in South Carolina. Two isolates of PMV that cause CGMD (PMV-C) were consistently transmitted by standard sap inoculation techniques to centipedegrass but erratically to Texas Common St. Augustinegrass. Symptom development was more rapid when temperatures were between 22 and 30 C than between 13 and 20 C. The PMV-C isolates were also transmitted by clipping centipedegrass with shears that had been used previously to clip infected PMV-C centipedegrass. Nimblewill was identified as an additional host of PMV-C. It does not appear that PMV-C significantly impairs growth of centipedegrass in lawns or in a greenhouse environment.