Seed Yield of Kentucky Bluegrass as Affected by Post-Harvest Residue Removal1
- R. D. Ensign,
- V. G. Hickey and
- M. D. Bernardo2
Field burning of post-harvest residue has been an established management practice for economical production of Kentucky bluegrass (Poa pratensis L.) seed. Fields not burned soon after harvest usually have poor seed production in the following year. Residue remaining on fields shades, and thereby restricts tiller growth and subsequent seed yield. To explore the hypothesis, polyethylene shade screens which excluded 30 and 67% of sunlight were placed over September field-burned ‘Baron’ Kentucky bluegrass plants for 75 and 130 days. Other treatments included mechanical vacuum clipping at 2.5, 7.6, and 15.2 cm levels, field burning of residue and no residue removal. The grass was seeded on Thatuna and Naff silt loam series (fine-silty, mixed, mesic Xeric Argialbolls and fine-silty, mixed, mesic Ultic Argixerolls, respectively). Tiller numbers from plants where residue was removed to the 2.5, 7.6, and 15.2 cm levels in 1978-1979 were comparable to tiller numbers from plants shaded at the 30% level. Tiller numbers for plants shaded at 67% were comparable to tiller numbers where residue was removed at 15.2 cm, or where no residue was removed. Leaf and sheath length were generally inversely related to the level of residue removal. Panicle numbers for shading at 67% in 1979-1980 were comparable to residue removal at 15.2 cm and no removal of residue. Seed yields from artificially shaded plants in 1978-1979 were 51 to 55% less than yields from plants where residue was not removed. In 1979-1980, seed yields from shaded plants at the 67% light exclusion for 130 days were 76% of yields from plants of openfield burn but did not differ from yields from plants where residue was not removed or mechanically clipped to heights of 7.6 or 15.2 cm. It was concluded that reduced Light penetration into the canopy could change plant growth and reduce seed production potential.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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