CaSi Doesn't Strengthen Creeping Bent, Tall Fescue against Foliar Disease

Some researchers report that one potential tool for reducing fungicide requirements on turfgrasses may be the use of silicon (Si) fertilizers. Silicon has been reported to suppress diseases on various crops in the last decade (Raid et al., 1992; Cherif et al., 1994; Deren et al, 1994; Seebold et al, 2000; Seebold et al., 2001). Researchers in North Carolina found that brown patch and dollar spot on creeping bentgrass were reduced approximately 20 percent and 30 percent, respectively, when soluble potassium silicate (21 percent SiOz) at 0.5 pounds per 1,000 square feet was applied (Uriarte et al., 2004). However, in that study measurable increases in potassium but not Si occurred in creeping bentgrass leaves. Gray leaf spot on St. Augustinegrass was reduced 9 percent to 28 percent by Si alone (100 pounds per 1,000 square feet) and 59 percent to 68 percent with the comContinued on page 60 IN THIS ISSUE