POST-HARVEST RESIDUE MANAGEMENT OF KENTUCKY BLUEGRASS FOR SEED PRODUCTION IN CENTRAL OREGON

Fourth year (1984) seed yields were obtained from Merit, Baron, Parade, America, Mystic, and Rugby Kentucky bluegrass varieties that had been subjected to eight residue removal schemes in August 1983. This is part of the 1984 data from a study initiated in the fall of 1980 to determine the effect that different regrowth drying/removal techniques might have on the subsequent year's seed production. Total rainfall of 1.9 inches from the 1983 seed harvest to August 1 obliterated the seed yield advantage from early open-field burning (OFB) generally observed because plots for this treatment had re-growth which did not exist in prior years of this study. Therefore, all varieties were similar in yield after OFB and Treatment 7 (straw fluffed up out of regrowth, OFB, and resi-due clean-up with a propane field burner). Paraquat was a more effective dessicant for regrowth than Contact (Dinitro-) so OFB removed residue satisfactorily which eliminated the need to use the propane field burner. Parade, America and Rugby appear to have a greater tolerance to regrowth drying and removal by burning than the others. All varieties studied do not respond the same to each management method. The production of Kentucky bluegrass (Poa pratensis L.) seed has been an important enterprise in Central Oregon for many years. Growers have recognized the necessity of removing the postharvest residue for maintenance of maximum seed produc-tivity throughout the life of the stand. The most economical and effective technique has been the use of open field burning during the last of August and the first week of September. From none to various amounts of straw have been burned on dif-ferent fields depending, in many cases, upon the market price of bluegrass straw for hay. In years when field soil moisture is low and no or very little rainfall is received, the blue grass residue can be burned quite effectively. However, if for various reasons the bluegrass plants remain green through harvest or initiate regrowth after combining, the growers ar