scholarly journals Selection Criteria for Drought-resistance Breeding in Turfgrass

1994 ◽  
Vol 119 (6) ◽  
pp. 1317-1324 ◽  
Author(s):  
Yuguang Zhao ◽  
George C.J. Fernandez ◽  
Daniel C. Bowman ◽  
Robert S. Nowak
Keyword(s):  
Water Stress ◽  
Water Use ◽  
Drought Resistance ◽  
Poa Pratensis ◽  
Resistance Breeding ◽  
Gompertz Model ◽  
Kentucky Bluegrass ◽  
Color Score ◽  
Physiological Attributes ◽  
The Difference

Cumulative evapotranspiration (ETcum) patterns of 10 commercially available cool-season turfgrass species and cultivars were evaluated under progressive water stress in the semi-field conditions using a gravimetric mass balance method in three studies. At the end of water stress, the cultivars were visually scored for green appearance on a 0 (no green) to 10 (100% green) scale. A Gompertz nonlinear model gave a best fit to ETcum vs. days adjusted for pan evaporation variation. Two of the ETcum attributes (ti, the time during which the rate change in ET is zero, and ETmax, the maximum ET rate) estimated from the Gompertz model appeared to reflect efficient water-use attributes in the turfgrass. Among the physiological screening techniques studied, electrolyte leakage, relative water content, and the difference between canopy and air temperature appeared to separate cultivars by drought resistance and water use efficiency (WUE). These physiological attributes were also relatively easy to measure and had high correlations with color score and WUE. Biplot display is a graphical technique in which the interrelationships between the cultivars and water-use attributes can be displayed together. Based on ti, ETmax, color score, and physiological attributes, `Wabash' and `Bristol' Kentucky bluegrass (Poa pratensis L.), `Aurora' hard fescue (Festuca ovina var. duriuscula L. Koch.), and `FRT-30149' fine fescue (F. rubra L.) were identified as cultivars with higher WUE.

scholarly journals Comparing Turfgrass Cumulative Evapotranspiration Curves

HortScience ◽  
1993 ◽  
Vol 28 (7) ◽  
pp. 732-734 ◽  
Author(s):  
George C.J. Fernandez ◽  
Belinda Love
Keyword(s):  
Water Stress ◽  
Regression Models ◽  
Poa Pratensis ◽  
Gompertz Model ◽  
Kentucky Bluegrass ◽  
Festuca Rubra ◽  
Pan Evaporation ◽  
Nonlinear Regression Models ◽  
Fine Fescue ◽  
Best Fit

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.

scholarly journals 429 Detecting Incipient Water Stress in Buffalograss and Kentucky Bluegrass through Foliage Temperature using Lowcost Infrared Sensors

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 467C-467
Author(s):  
J. Ryan Stewart ◽  
Roger Kjelgren
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Poa Pratensis ◽  
Warm Season ◽  
Canopy Temperature ◽  
Kentucky Bluegrass ◽  
Infrared Sensors ◽  
Drought Avoidance

Infrared sensors were used to quantify canopy temperature and thus detect differences in incipient water stress between a cool-season grass [Kentucky bluegrass (KBG) (Poa pratensis)] and a warm-season grass [buffalograss (BG) (Buchloe dactyloides)]. The infrared sensors, connected to a datalogger, measured average hourly leaf–air temperatures (TL–TA) 1 m above eight replicate plots of Kentucky bluegrass and eight replicate plots of buffalograss. Air temperature and relative humidity from a nearby weather station were used to calculate the average hourly vapor pressure deficit (VPD). In late July, we ceased irrigating and measured TL–TA and soil water content while allowing the turf to dry down for 5 weeks. Soil water content was measured with a neutron probe. Both species exhibited a significant relationship between TL–TA and VPD. As the VPD increased, TL–TA decreased in both species (KBG r2 = 0.73, BG r2 = 0.71) on the 2nd day after an irrigation during well-watered conditions. An artifact was created on the first day after an irrigation as a result of excessive surface evaporation. KBG and BG were similar under well-watered conditions. KBG had a higher TL–TA after 4 to 5 days without irrigation. By contrast, BG did not have a higher TL–TA until 25 to 30 days without irrigation. Part of BG's drought avoidance was extraction of soil water down to 0.9 m vs. 0.45 m for KBG.

scholarly journals Residential Landscapes, Homeowner Attitudes, and Water-wise Choices in New Mexico

2006 ◽  
Vol 16 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Brian H. Hurd ◽  
Rolston St. Hilaire ◽  
John M. White
Keyword(s):  
New Mexico ◽  
Water Use ◽  
Water Conservation ◽  
Poa Pratensis ◽  
Community Support ◽  
Kentucky Bluegrass ◽  
Population Growth Rates ◽  
Residential Landscapes ◽  
And Performance ◽  
Conservation Plans

Residential landscapes are responsible for a large share of the water use of New Mexico communities. Water conservation plans and programs are being promulgated throughout New Mexico and the western U.S. as concern grows over the sufficiency and variability of present supplies, sustainability of current population growth rates, and desire for enhanced economic development. Household attitudes, choices, and behaviors ultimately underlie the success and performance of community water conservation programs. Homeowners in three New Mexico cities were surveyed concerning their attitudes and behavior toward water use, water conservation, and residential landscapes. Findings suggest that New Mexico's homeowners are mindful of the water resource challenges faced by communities, and are prepared to shoulder responsibility for stewarding the state's water resources. There is broad community support to limit traditional turfgrasses [e.g., kentucky bluegrass (Poa pratensis)] and to increase the areas planted to native, natural, and water-conserving landscapes; for example, 92% favored limiting turfgrass to less than 25% of the area around public buildings. Evidence showing that 40% are not “content” with their current landscape suggests that significant impediments remain and limit still greater adoption of water-conserving landscapes and subsequent potential for increased household water savings.

RESPONSE OF DURUM WHEAT CULTIVARS TO WATER STRESS IN THE FIELD AND GREENHOUSE

1983 ◽  
Vol 63 (4) ◽  
pp. 801-814 ◽  
Author(s):  
GETINET GEBEYEHOU ◽  
D. R. KNOTT
Keyword(s):  
Water Stress ◽  
Durum Wheat ◽  
Drought Resistance ◽  
Yield Components ◽  
Triticum Turgidum ◽  
Kernel Weight ◽  
Greenhouse Experiment ◽  
Water Regimes ◽  
Growing Period ◽  
The Difference

Experiments were conducted in the field and in the greenhouse to measure differences in drought resistance among durum wheat (Triticum turgidum L.) cultivars. Nine cultivars were tested in 1976 and 12 in 1977 in duplicate tests grown adjacent to each other under rainfed and irrigated conditions in the field. The drought resistance of the cultivars was measured as the difference in their performance under the two water regimes. For yield, there was no significant interaction between the cultivars and the water regimes in either year. Thus, the cultivars did not appear to differ significantly in drought resistance. They did differ significantly in the effect of water stress on the yield components. However, the performance of the cultivars was not consistent either for the yield components or between years. In one greenhouse experiment, six cultivars were grown in large containers. One set of plants was watered at regular intervals while a second set was watered only until 5 days after anthesis in the main spikes. Water stress caused major, correlated reductions in grain yield, 1000-kernel weight, and length of the growing period. However, the differences among the cultivars largely depended on their vegetative growth under nonstress, those with the most growth showing the largest reduction from stress. In a second greenhouse experiment, the 12 cultivars were grown in 15-cm pots at three moisture levels. For yield, there was no interaction between cultivars and moisture levels. Overall, the data provided little evidence of consistent differences among cultivars in resistance to moisture stress.Key words: Drought resistance, components of yield, yield, durum wheat (Triticum turgidum L.).

Physiological attributes associated with early-season drought resistance in spring durum wheat cultivars

1998 ◽  
Vol 78 (2) ◽  
pp. 227-237 ◽  
Author(s):  
R. El Hafid ◽  
Dan H. Smith ◽  
M. Karrou ◽  
K. Samir
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Durum Wheat ◽  
Drought Resistance ◽  
Triticum Durum ◽  
Dry Matter ◽  
Wheat Cultivars ◽  
Early Season ◽  
Physiological Attributes ◽  
Triticum Durum Desf

One of the common features of the Mediterranean climate in North Africa is the uncertainty of rainfall immediately after wheat (Triticum durum Desf) emerges. Relatively little work has been done to compare the drought resistance of spring durum wheat cultivars under early-season drought stress. There is a limited insight into the physiological basis of spring durum wheat drought resistance in rainfed Mediterranean regions. Field experiments were conducted in 1995 and 1996 growing seasons, and a greenhouse experiment was conducted in 1996 to examine differences in some physiological characters among six spring durum wheat cultivars in response to different durations of early-season drought, and rewatering; and to determine the relationships of these characters to drought resistance. Six spring durum wheat cultivars were evaluated under four water regimes. Water regime treatments were: a well-irrigated treatment; and three water deficit treatments imposed during the period from emergence through either the onset of tillering, mid-tillering or the end of tillering. Cultivars differed widely in their response to early season water stress. Under drought stress conditions, grain yield, aboveground dry matter yield, water use efficiency for the grain (WUEg) and for the total dry matter (WUEdm) were strongly positively associated with net CO2 uptake:transpiration ratio (A/E), and osmoregulation capacity. It is concluded that drought-induced changes in A, A/E, stomatal resistance, and osmotic adjustment are possible key control points in determining the drought-resistance of a cultivar. Furthermore, there is a substantial degree of intraspecific variation for the above mentioned physiological attributes to explore as a selection tool. Selection for high osmoregulation capacity and high A/E ratio would seem to be a justifiable means of improving total dry matter and grain yield under conditions of early-season water stress. Key words: Wheat, Triticum durum Desf., physiological attributes, early-season drought

Development, growth, water-use and yield of a spring and a winter wheat in response to time of sowing

1992 ◽  
Vol 43 (3) ◽  
pp. 493 ◽  
Author(s):  
DJ Connor ◽  
S Theiveyanathan ◽  
GM Rimmington
Keyword(s):  
Water Stress ◽  
Winter Wheat ◽  
Water Use ◽  
Mean Value ◽  
Floral Initiation ◽  
Crop Water ◽  
Crop Water Use ◽  
Cycle Growth ◽  
Rainfed Conditions ◽  
The Difference

The development, growth, water-use and yield of spring (Banks) and winter (Quarrion) cultivars of wheat were measured in response to time of sowing under rainfed conditions. Crop duration shortened in both cultivars (210 to 120 days) as sowing was delayed from May to August with Quarrion maintaining the longer cycle. The difference between cultivars was small (3 days) at the May sowing increasing to 21 days in August, but there were large differences in the relative durations of the component phenophases. Consistent with the shorter cycle, growth of both cultivars decreased as sowing was delayed from May to July (11.3 to 9.9 t ha-1). With August sowing, the pattern continued in Banks (6.7 t ha-1) but not in Quarrion. Seasonal evapotranspiration (ETa) of both cultivars was similar, declining from 306 to 262 mm as sowing was delayed from May to July. On average, Quarrion used more water (34%) of ETa than Banks (19%) during emergence to floral initiation (E-FI), and a corresponding smaller proportion during subsequent phenophases, floral initiation to anthesis (FI-A ) (31 v. 41%) and anthesis to maturity (A-M) (35 v. 41%). The differences between cultivars increased as sowing was delayed from May to August. Maximum evapotranspiration (ETm), estimated by the Penman equation, was evaluated against measurements made with weighed lysimeters. The ratio ETa/ETm fell progressively during the crop cycles and was always smaller for the later-developing Quarrion than for Banks. Crops of both cultivars had adequate water supply during E-FI, mean value of the ratio 0.93, but experienced water stress during FI-A and A-M. Stress was greater in Quarrion (ratios 0.71 and 0.56) than in Banks (0.88 and 0.62). In Quarrion, yield decreased progressively from 4.3 t ha-1 when sown in May to 1.6 t ha-1 in August. In contrast, yield of Banks increased from 3.7 t ha-1 in May to 4.5 t ha-1 in June and then decreased to 3.5 t ha-l in July and 2.6 t ha-1 in August. Crop water-use efficiencies are analysed for ETa (WUE) and for transpiration (TE). Excluding the August-sown crops, they ranged respectively over 11.9 to 14.8 and 25.0 to 32.5 for Quarrion and over 11.0 to 15.7 and 23.3 to 31.6 kg ha-1 mm-1 for Banks. Maximum efficiencies were not achieved by the crops of greatest yield.

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