INFLUENCE OF TEMPERATURE ON GERMINATION OF BENTGRASS CULTIVARS AND CULTURAL PRACTICES ON ESTABLISHMENT OF CREEPING BENTGRASS
Open Access
- Author:
- Carroll, Devon E
- Graduate Program:
- Agronomy
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- November 15, 2018
- Committee Members:
- John Kaminski, Thesis Advisor/Co-Advisor
Peter Landschoot, Thesis Advisor/Co-Advisor
David Robert Huff, Committee Member
Brian Horgan, Committee Member - Keywords:
- germination
establishment
creeping bentgrass
cultural practices
temperature - Abstract:
- Winterkill of turfgrasses on golf course putting greens is highly unpredictable and problematic for superintendents in northern climates, specifically in the Northeastern United States. Harsh winters in the 2013-14 and 2014-15 seasons left many superintendents facing the difficult challenge of trying to recover from turf loss at a time coinciding with the opening of golf courses for play. Creeping bentgrass (Agrostis stolonifera L.; CBG) putting greens are commonly infested with annual bluegrass (Poa annua L.; ABG). Annual bluegrass is known to be an aggressive weed and a species that is difficult to eradicate. Over time, ABG can become the dominant and preferred species to maintain on putting greens. This dominance of ABG in cold climates can become problematic due to the susceptibility of the species to temperature extremes when compared to CBG. In the event of winterkill, superintendents may discover turf loss in sporadic voids or possibly the loss of entire ABG putting greens after snow melt that occurs. If winterkill occurs, re-establishment of the putting surface via CBG seed or sod may be required. Seeding is often the preferred method of recovery, but temperatures in the early spring generally are considered suboptimal for germination. Limited information is available on the influence of suboptimal temperatures on bentgrass germination. The evaluation of CBG cultivar performance (e.g., germination) at low temperatures would be valuable to superintendents seeding in early spring. Additionally, information on effective methods of cultivation, nitrogen (N) fertilization, and seeding rates could optimize establishment of CBG and reduce losses of golf course revenue due to course closure. The objectives of this study were to: 1) determine the impact of suboptimal temperatures on bentgrass cultivar germination; and 2) elucidate the influence of cultivation methods, starter fertilizer rate, and seeding rate on the establishment of CBG. Differences in germination among cultivars were observed when seed was incubated at 10ºC. Samples of ‘Pure Select’, ‘Greentime’, ‘Crystal BlueLinks’, and ‘Penn A-4’ had the highest germination at 10ºC when incubated in the presence or absence of light. ‘Mackenzie’, ‘PLS’, ‘Tyee’, and ‘Villa’ exhibited the lowest germination at 10ºC. Germinability at low temperatures should be considered as a factor in cultivar selection for early spring seeding at suboptimal temperatures. Field experiments indicated that seeding at a rate of 73 kg seed ha-1 and fertilizing at a rate of 73 kg N ha-1 increases seedling vigor and percent ground cover compared to lower seeding and N rates. Slicing was an effective method of cultivation. Putting greens cultivated by slicing alone, slicing + 13-mm hollow tine aeration, and slicing + 6-mm hollow tine aeration generally showed similar seedling vigor and percent cover, indicating that superintendents could use slicing alone to save money and time on hollow tine aeration. These cultivation practices, combined with careful cultivar selection, can optimize early spring seeding and may result in quicker recovery where winterkill occurs.