Open-field burning has been an effective, economical, and widespread
method of post-harvest residue management in creeping red fescue seed
production in the Willamette Valley since the late 1940s. However, the use of field
burning has been legislatively restricted due to air quality and safety issues. The
foliar-applied plant growth regulator trinexapac-ethyl (TE), commercialized in the
USA as Palisade, has been accepted by producers as a yield enhancing agent
and is considered here as an alternative to open-field burning over a four-year
period.
The effects of open-field burning versus mechanical removal (flailing) of
post-harvest residue, and spring versus fall applications of TE on seed yield, dry
matter partitioning, and seed yield components were evaluated in a split-plot
design. The response to the different treatment combinations differed across
years. The young stand responded with a seed yield increase to spring TE
applications, regardless of residue management treatment. However, as the stand
aged, field burning became critical for maintaining high yields and, in 2003 and
2004, only spring TE applications resulted in seed yield increases in burned plots.
The higher potential seed yield achieved in burned plots over flailed plots,
as a result of a higher number of panicles per unit area and spikelets per panicle,
was critical for maintaining high seed yields as the stand aged. Spring
applications of TE, further increased seed yield over the untreated check by
increasing the number of florets per spikelet, reducing fertile tiller height and
lodging and consequently, favoring pollination and fertilization of the florets. Late
spring TE applications also increased 1000-seed weight in 2003 and 2004.
Although spring applications of TE were a promising alternative to open-field
burning early during the life of the stand, as the stand aged they did not
increase seed yield on flailed plots. Fall TE applications did not have a consistent
effect on seed yield, dry matter partitioning or seed yield components, and were
found not to be a viable management practice. / Graduation date: 2005
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29428 |
| Date | 22 October 2004 |
| Creators | Zapiola, Maria Luz |
| Contributors | Chastain, Thomas G. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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