Protect Turf from Nematodes

OVERSEEDING: WHICH GRASSES ARE BEST 1971 overseeding results in south Florida. A. E. Dudeck andE. O. Burt. Florida Turf. 4 (5):3-6. (from the University of Florida Agricultural Research Center, Fort Lauderdale, Fla. 33314). The objective of this investigation was to evaluate monostands and polystands of various cool season turfgrasses for use in overseeding dormant bermudagrass putting greens under the conditions of southern Florida. Eighteen individual cool season turfgrasses and six cool season turfgrass mixtures were evaluated. The specific cultivars evaluated included (a) Lucerne, Manhattan, Medalist 2 and Pennfine perennial ryegrass, (b) Italian ryegrass, (c) Park, Prato and Primo Kentucky bluegrass, (d) Pennlawn red fescue and (e) Dawson chewings fescue. The ryegrasses were seeded at 45 pounds, the fine leafed fescues at 20 pounds and the Kentucky bluegrasses at 10 pounds per 1,000 square feet. The seedings were made December 16th onto a semi-dormant Tifdwarf bermudagrass green. Replicated plots of 25 square feet in size were utilized. The overseeding procedures included extensive vertical mowing, four times over the area in four different directions. This was followed by seeding. Subsequently, the green was topdressed sufficiently to cover the seed and lightly dragged with the back of a rake. The cultural system following planting included daily mowing at onequarter inch. The area received an initial fertilization of 16-4-8 containing secondary and trace elements. Subsequently, ammonium sulfate and urea were applied alternately at monthly intervals. All fertilizer applications were made at an equivalent rate of one pound nitrogen per 1,000 square feet. Preventive fungicide applications were made at five-day intervals during the initial 30-day establishment period. An alternating selection of fungicides was used to provide broad disease control. The various overseeding treatments utilized were evaluated in terms of establishment rate, color, leaf texture, mowing quality, vertical shoot growth rate, disease proneness and effectiveness of spring transition back to bermudagrass. The results of this study will be discussed in terms of each specific type of data evaluated. First, the establishment rate. The ryegrass possessed the most rapid establishment rate with no significant differences being observed among the various cultivars. No differences were observed between the Kentucky bluegrasses and fine leafed fescues during the first week. Subsequently, the fescues rated intermediate in establishment whereas the Kentucky bluegrasses were slowest. Among cultivars of these species, Park was superior to Prato and Primo, whereas Dawson ranked superior to Pennlawn. Thirty eight golf course superintendents from South Florida visually rated these experimental plots for turfgrass quality five weeks after seeding. As a group, the ryegrasses ranked superior along with those mixtures containing high percentages of ryegrass. The Kentucky bluegrasses ranked lowest with the fine leafed fescues being in the intermediate range. Italian ryegrass ranked poorer than the perennial ryegrass cultivars. Vertical shoot growth measurements were made by collecting clipping weights approximately 10 weeks continued on page 21 I F . . .