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Benjamin Wherley and Thomas R. Sinclair

studies that turfgrass evapotranspiration rates increase with increasing N fertilization, a relationship often attributed to changes in leaf elongation rate and/or the amount of transpiring leaf area exposed to the atmosphere between mowings ( Ebdon et al

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C. S. Tan and R. E. C. Layne

Abstract

A 2-year study was made of 2 methods of scheduling irrigation of peach (Prunus persica (L.) Batsch cv. Harken/Siberian C). In each year, irrigation schedules necessary to prevent the available soil moisture (ASM) from falling below 50% level in the top 30 cm were essentially the same, whether determined from direct measurement of soil moisture or predicted from a simplified Priestley and Taylor évapotranspiration model.

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M.J. Hattendorf and J.R. Davenport

Cranberry (Vaccinium macrocarpon Ait.) evapotranspiration (ET) has not been documented. Micrometeorological techniques based on canopy temperature minus air temperature were used to estimate ET on `Stevens' and `Crowley' cranberry at Long Beach (lat. ≈46°20′N, long. 124°W) and Grayland (lat. ≈46°47′N, long. 124°W), Wash., in 1991 and 1992, respectively. Cranberry ET was 55% of Priestley–Taylor reference ET and ranged from <0.5 to >4 mm·d–1. The Priestley–Taylor reference ET was a very good predictor of cranberry ET (r 2 = 0.795). Running 7-day cumulative ET ranged from 7 to 17 mm·week–1.

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Lee F. Johnson, Michael Cahn, Frank Martin, Forrest Melton, Sharon Benzen, Barry Farrara, and Kirk Post

crop canopy, and exerts a direct influence on energy exchange at the land surface that drives the evapotranspiration process ( Allen et al., 1998 ). As such, estimates of Fc can provide a basis for Kc and crop ET (ETc) monitored in vegetables ( Bryla et

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Eric W. Kerschen, Caleb Garten, Kimberly A. Williams, and Melanie M. Derby

water vapor emission from foliage) and evaporation (conversion of water to vapor at the surface of root medium), the combination of which is evapotranspiration. Many low-light plant species can grow indoors under existing lighting conditions ( DelPrince

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R. C. Shearman

Abstract

Twelve perennial ryegrass (Lolium perenne L.) cultivars were evaluated for evapotranspiration (ET) rates in a field study, using mini-lysimeters placed in a turf area with 150 m fetch. Cultivars differed in ET, verdure, vertical elongation rate (VER), and root density. Evapotranspiration ranged from a low of 4.93 mm·day-1 for ‘Prelude’ on 3 Sept. 1987 to a high of 9.98 mm·day-1 for ‘Linn’ on 13 May 1988. ‘Linn’ had a mean VER that was twice that of ‘Prelude’. VER was positively correlated (r = 0.93) and verdure was negatively correlated (r = −0.89) with ET. Crop coefficients (Kc) ranged from 0.81 to 1.03. ‘Linn’ had a Kc > 1 on five of the six dates tested.

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George C.J. Fernandez and Belinda Love

Twenty-five commercially available turfgrass cultivars were evaluated for cumulative evapotranspiration (ETcum) attributes under progressive water stress for 0 to 21 and 0 to 24 days using the gravimetric mass balance method in two greenhouse studies. At the end of the water-stress treatment, the cultivars were scored visually for their green appearance on a 0 (no green) to 10 (100% green) scale. The Gompertz nonlinear model gave a best fit to ETcum vs. days adjusted for pan evaporation variation in the greenhouse compared with monomolecular and logistic nonlinear regression models. Two ETcum attributes—maximum evapotranspiration rates (ETmax) and inflection time (ti) (the time when the change in ET becomes zero)—were estimated for each cultivar using the Gompertz model. Based on final ETcum, ETmax, ti, and greenness score, `Bristol', `Challenger', and `Wabash' Kentucky bluegrass (Poa pratensis L.); `Shademaster' creeping fescue (Festuca rubra L.); `FRT-30149' fine fescue (F. rubra L.); and `Aurora' hard fescue (F. ovina var. duriuscula L. Koch.) were identified as low water-use cultivars.

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D. M. Kopec, R. C. Shearman, and T. P. Riordan

Abstract

Mini-lysimetry was used for evapotranspiration (ET) assessment of six tall fescue cultivars (Festuca arundinacea Schreb.) grown under field conditions. Crop coefficients (Kc) and fraction of available soil water were calculated. Cultivars differed in ET by as much as 18%. Turf-types had lower ET than forage-types, with ET rates of 6.6 and 7.2 mm·day–1, respectively. ‘Kenhy’ and ‘Kentucky 31’ had the highest and ‘Rebel’ and ‘Mustang’ had the lowest total ET for 16 days measured during Summer 1984. Cultivars differed in extraction of available soil water and capacity to meet ET demand. Cultivars differed in wilting tendency. ‘Mustang’ and ‘Rebel’ had low ET, but wilted early. ‘Adventure’ had a relatively high ET, but did not show signs of wilt.

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R. C. Shearman

Abstract

Twenty well-watered Kentucky bluegrass (Poa pratensis L.) cultivars were evaluated for evapotranspiration (ET) under controlled environment, using the water-balance method. ET ranged from a low of 3.86 mm·day−1 for ‘Enoble’ to a high of 6.43 mm·day−1 for ‘Merton’, ‘Birka’, and ‘Sydsport’. Cultivars differed in shoot density, verdure, root density, stomatal density, and stomatal index. Only verdure was significantly correlated (r = 0.60) to ET for the 20 cultivars. Five cultivars were selected using cluster analysis to represent categories of high, medium, and low ET rates. ET for these cultivars increased from 1.1- to 1.7-fold when temperature was increased from 25° to 35°C, depending on cultivar. ET at 35° was positively correlated to vertical elongation rate (r = 0.96), and negatively correlated to shoot density (r = − 0.87) and verdure (r = − 0.83) under well-watered conditions.

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Doudou Guo, Ziyi Chen, Danfeng Huang, and Jingjin Zhang

. Evapotranspiration model description The application of ET model relies on the availability of data, which is limited by the measurement equipment, expertise, climate, and historical data. Therefore, models reported in previous studies with fewer inputs and better