Carbon isotope discrimination of tall fescue cultivars across an irrigation gradient

2004 ◽  
Vol 84 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Kevin B. Jensen ◽  
Kay H. Asay ◽  
Douglas A. Johnson ◽  
Blair L. Waldron
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Tall Fescue ◽  
Line Source ◽  
Festuca Arundinacea ◽  
Carbon Isotope Discrimination ◽  
Water Levels ◽  
Forage Yield ◽  
Harvest Dates ◽  
Use Efficiency

Carbon isotope discrimination (Δ) has been proposed as an indirect criterion for evaluating water-use efficiency; however, limited information is available regarding the relationship between and dry matter yield (DMY) at different levels of irrigation. Ten cultivars of tall fescue (Festuca arundinacea Schreb.) were established in the field under a line-source irrigation system and defoliated five to six times per growing season. Objectives of our 2-yr study were to evaluate: (i) trends in Δ across a gradient of four water levels (WL-2, wettest to WL-5, driest) at a mid-summer harvest, (ii) the consistency among grass cultivars at one WL across two harvest dates, and (iii) relationships between Δ and DMY within and across water levels. Consistent and significant differences (P < 0.05) were found among cultivars for Δ when evaluated at WL-2 for Harvests 2 and 4 in successive years. Cultivars also differed significantly for Δ (P < 0.01) across four water levels when evaluated at Harvest 4. Relative differences among cultivars were consistent across water levels and between harvest dates. Although a curvilinear trend was evident for some cultivars, mean Δ values decreased in a near linear manner from WL-2 to WL-5. Based on orthogonal polynomials, the mean trend across water levels was partitioned as 95% linear and 5% quadratic. Correlations between Δ and DMY were nonsignificant at the higher water levels (WL-2 and 3), but correlations were positive at the lower water levels (WL-4 and 5). We conclude that under lower water levels, selection for low Δ in tall fescue cultivars will likely lead to decreased forage yield. Key words: Festuca arundinacea, forage yield, water-use efficiency, line source, delta

Divergent selection for carbon isotope discrimination in crested wheatgrass

1993 ◽  
Vol 73 (4) ◽  
pp. 1027-1035 ◽  
Author(s):  
J. J. Read ◽  
K. H. Asay ◽  
D. A. Johnson
Keyword(s):  
Water Use Efficiency ◽  
Carbon Isotope ◽  
Water Use ◽  
Dry Matter ◽  
Carbon Isotope Discrimination ◽  
Forage Yield ◽  
Crested Wheatgrass ◽  
Agropyron Desertorum ◽  
Use Efficiency ◽  
Selection For

Because plant growth on semiarid rangelands is frequently water-limited, breeding for enhanced water-use efficiency (WUE, kg dry matter gained per kg water transpired) should improve forage production on these areas. In crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes], variation for carbon isotope discrimination (Δ) has been negatively associated with WUE, suggesting that selection for lowered Δ would increase WUE. To determine the potential of altering Δ through breeding, we selected nine clones from a crested wheatgrass breeding population based on their Δ values, equally subdivided them into three groups (low, medium, and high Δ), and made a series of diallel crosses within each group. The parental clones and single-cross progenies were established in the field as replicated spaced plants on 1-m centers in spring 1989. Forage dry matter yield and Δ were determined in 1990 and 1991; leaf gas exchange traits were determined for low and high Δ classes in 1990, and for low, medium, and high Δ classes in 1991. The previous ranking of Δ classes was confirmed in the present studies. Combined across years, values for Δ, leaf CO2 exchange rate (CER), and stomatal conductance (gs) were significantly (P < 0.05) lower in the low than high Δ class. When data were combined across clones and progenies, Δ was negatively correlated with leaf intrinsic water-use efficiency (WUEi, expressed as the CER/gs ratio) in 1990 (r = −0.87**, df = 14) and in 1991 (r = −0.83**, df = 23). Forage yield and Δ were not correlated, suggesting that the two traits may be under separate genetic control. Progenies from crosses among the low-Δ clones had significantly lower Δ values than progenies from either the medium-Δ or high-Δ clones during each year and when the data were combined across years. Divergent selection for low Δ also was reflected by improved WUEi in the subsequent generation. Moreover, narrow-sense heritability values for Δ were in excess of 0.75 and correlations between progeny means for Δ and means of the corresponding midparents were significant in each of the three analyses (r = 0.87** in 1990, 0.91** in 1991, and 0.92** in the combined analysis). These results complement earlier findings and confirm that genetic improvement for WUE can be effectively achieved in crested wheatgrass through indirect selection for Δ. Key words: Agropyron desertorum, water-use efficiency, parent-progeny correlations, drought, carbon isotope ratio, grass breeding, forage yield

scholarly journals Effect of Deficit Irrigation and Reduced N Fertilization on Plant Growth, Root Morphology and Water Use Efficiency of Tomato Grown in Soilless Culture

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 228
Author(s):  
Ikram Ullah ◽  
Hanping Mao ◽  
Ghulam Rasool ◽  
Hongyan Gao ◽  
Qaiser Javed ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Irrigation Water ◽  
N Fertilization ◽  
Water Levels ◽  
Growth And Yield ◽  
Root Surface Area ◽  
Irrigation Water Use Efficiency ◽  
Irrigation Water Use ◽  
Use Efficiency

This study was conducted to investigate the effects of various irrigation water (W) and nitrogen (N) levels on growth, root-shoot morphology, yield, and irrigation water use efficiency of greenhouse tomatoes in spring–summer and fall–winter. The experiment consisted of three irrigation water levels (W: 100% of crop evapotranspiration (ETc), 80%, and 60% of full irrigation) and three N application levels (N: 100%, 75%, and 50% of the standard nitrogen concentration in Hoagland’s solution treatments equivalent to 15, 11.25, 7.5 mM). All the growth parameters of tomato significantly decreased (p < 0.05) with the decrease in the amount of irrigation and nitrogen application. Results depicted that a slight decrease in irrigation and an increase in N supply improved average root diameter, total root length, and root surface area, while the interaction was observed non-significant at average diameter of roots. Compared to the control, W80 N100 was statistically non-significant in photosynthesis and stomatal conductance. The W80 N100 resulted in a yield decrease of 2.90% and 8.75% but increased irrigation water use efficiency (IWUE) by 21.40% and 14.06%. Among interactions, the reduction in a single factor at W80 N100 and W100 N75 compensated the growth and yield. Hence, W80 N100 was found to be optimal regarding yield and IWUE, with 80% of irrigation water and 15 mM of N fertilization for soilless tomato production in greenhouses.

scholarly journals Gas exchange and water use efficiency in seedlings of tree species from caatinga under water levels and potassium

2021 ◽  
Vol 1 (53) ◽  
pp. 218
Author(s):  
Ediglécia Pereira Almeida ◽  
Antonio Lucineudo Oliveira Freire ◽  
Ivonete Alves Bakke ◽  
Cheila Deisy Ferreira
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Tree Species ◽  
Water Levels ◽  
Use Efficiency

Forage yield, water use efficiency, and soil fertility response to alfalfa growing age in the semiarid Loess Plateau of China

2021 ◽  
Vol 243 ◽  
pp. 106415
Author(s):  
Linlin Wang ◽  
Junhong Xie ◽  
Zhuzhu Luo ◽  
Yining Niu ◽  
Jeffrey A. Coulter ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Water Use Efficiency ◽  
Water Use ◽  
Loess Plateau ◽  
Forage Yield ◽  
Growing Age ◽  
Use Efficiency

scholarly journals Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range

2017 ◽  
Vol 389 ◽  
pp. 285-295 ◽  
Author(s):  
Eladio H. Cornejo-Oviedo ◽  
Steven L. Voelker ◽  
Douglas B. Mainwaring ◽  
Douglas A. Maguire ◽  
Frederick C. Meinzer ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Carbon Isotope Discrimination ◽  
Basal Area ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Intrinsic Water Use Efficiency ◽  
Area Growth ◽  
Use Efficiency
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