Fry, Jack Douglas, authorButler, Jackie D., advisorWallner, Stephen J., committee memberSmith, D. D., committee memberMarlatt, William E., committee memberMoore, Frank D., III, committee member2023-01-272023-01-271987https://hdl.handle.net/10217/236126Covers not scanned.Several investigations were undertaken to better define water requirements of turf canopies in an area of limited precipitation. Potential evapotranspiration (ET) (i.e., ET under conditions where soil water is not limiting) was determined using lysimeters in the field in three studies. When evaluated under putting green conditions, annual bluegrass (Poa annua L.) had a significantly lower water use rate (4.6 mm day-1) than creeping bentgrass (Agrostis palustris Huds.) (4.9 mm day-1) during the summer of 1986, but not 1985. Furthermore, both species had lower water use rates in 1986 when cut at 0.6 cm (4.6 mm day-1) compared to 1.2 cm (4.9 mm day- 1). Evapotranspiration rates of several turf weeds and groundcovers were also evaluated using lysimeters in the field. Results indicated that white clover (Trifolium repens L.), a C3 dicot, had the highest mean water use rate of all species (6.6 mm day-1). Lowest water use rates were seen with dichondra (Dichondra repens J.R. Forst. and G. Forst.), a C4 dicot, and barnyard grass [Echinochloa crusgalli (L.) Beauv.], a c. monocot (4.2 and 4.4 mm day-1, respectively). 'Merion' Kentucky bluegrass (Poa pratensis L.), yellow foxtail [Setaria glauca (L.) Beauv.], and crabgrass [Digitaria ischaemum (Schreb.) Muhl.] exhibited intermediate ET rates. Potential ET rates of 'Merion' Kentucky bluegrass and 'Rebel' tall fescue (Festuca arundinacea Schreb.) were determined during establishment using lysimeters. Over two summers, the mean ET rate for these two species was 5.2 and 5.3 mm day-1, respectively. In 1985, tall fescue began using significantly more water than Kentucky bluegrass twenty days after seeding. Tall fescue, irrigated at 50 and 100% of potential ET of a mature turf, did not achieve satisfactory establishment at the former irrigation level. Preplant soil incorporation of a hydrophilic polymer was also evaluated in greenhouse and field studies for effectiveness in reducing tall fescue drought stress during establishment. When applied at reasonable rates, the polymer was ineffective in enhancing tall fescue establishment. Mature 'Reliant' hard fescue [Festuca ovina var. duriuscula (L.) Koch.] and 'Rebel' tall fescue were evaluated in field plots under irrigation levels of 50, 75, and 100% of potential ET, applied on 2, 4, 7, or 14 day intervals. Hard fescue had the best quality when irrigated at 75 or 100% of potential ET on 2 or 4 day intervals. Acceptable tall fescue quality resulted when turf was watered once weekly at 50% of potential ET. These studies have better defined water management requirements and conservation strategies for turf canopies where water supplies are often limited.doctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Turf managementTurfgrassesEvapotranspiration -- MeasurementPlant-water relationshipsText