Kentucky Bluegrass Seed Production Characteristics as Affected by Residue Management1
- V. G. Hickey and
- R. D. Ensign2
Seed productivity of Kentucky bluegrass (Poa pratensis L.) is usually improved by open field burning of post-harvest residue. This field study compared the effects of field burning and mechanical removal of post-harvest residue on Kentucky bluegrass plant growth and seed yields. ‘Merion’, ‘Nugget’, ‘Baron’, ‘Glade’, and ‘South Dakota’ Kentucky bluegrass cultivars were seeded on a Latahco soil, (fine-silty, mixed, frigid argiaquic Agrialboll) in 1976. Residue removal treatments were stripped across the cultivars in 1977, 1978, 1979, and 1980. Seed yields where residue was removed by burning were 1.5 times greater in 1979,1.6 times greater in 1980, and 1.7 times greater in 1981 than yields where residue was mechanically removed to 2.5 cm. Seed yields where residue was removed by burning were 2.0 times greater in 1979, 1.9 times greater in 1980, and 2.6 times greater in 1981 than yields from plants where residue was mechanically removed to 7.6 cm. Panicle and tiller numbers were reduced where residue was mechanically removed to 2.5 or 7.6 cm compared to panicle and tiller numbers where residue was burned. Tiller leaf sheath lengths were not different where residue was burned or removed to 2.5 cm and were shorter than where residue was removed to 7.6 cm. Rhizome weights were reduced where residue was burned compared to weights where residue was clipped at 2.5 or 7.6 cm height in both 1980 and 1981. Root weights, when averaged across all five cultivars, were not affected by residue removal method. A significant cultivar × treatment interaction was noted for Glade, which produced more roots when clipped to 2.5 cm than when burned or clipped to 7.6 cm in both years. Significant cultivar × treatment interactions occurred in 1980 in tiller number which were reflected in panicle numbers and seed yields for Glade and South Dakota. Increased tiller production was associated with decreased rhizome weights. Since tiller apices have been found to control the upturning of rhizomes to produce new tillers, it was concluded that burning functions to reduce tiller apical control of rhizomes. The increased length of tiller leaf sheaths under decreasing heights of residue removal was concluded to be in response to decreased light penetration into the canopy.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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