scholarly journals The Effect of Night Temperature on Co2 Assimilation, Transpiration, and Water Use Efficiency in Agave Americana L

1973 ◽  
Vol 26 (4) ◽  
pp. 705 ◽  
Author(s):  
TF Neales
Keyword(s):  
Water Use Efficiency ◽  
Water Vapour ◽  
Water Use ◽  
Nutrient Solution ◽  
Co2 Assimilation ◽  
Night Temperature ◽  
Agave Americana ◽  
Use Efficiency ◽  
Water Vapour Fluxes

The CO2 and water vapour fluxes arising from the tops of a plant of A. americana, growing in nutrient solution, were continuously measured at night temperatures of 15, 25, and 36�C, the day temperature being held constant at 25�C.

Diurnal Time Course of Leaf Gas Exchange Rates and Related Characters in Drought-Acclimated and Irrigated Trifolium Subterraneum.

1995 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
J Vadell ◽  
C Cabot ◽  
H Medrano
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Trifolium Subterraneum ◽  
Co2 Assimilation ◽  
Carbon Gain ◽  
Assimilation Rate ◽  
Use Efficiency

The effects of drought acclimation on the diurnal time courses of photosynthesis and related characters were studied in Trifolium subterraneum L. leaves during two consecutive late spring days. Leaf CO2 assimilation rate and transpiration rate followed irradiance variations in irrigated plants. Under drought, a bimodal pattern of leaf CO2 assimilation rate developed although stomatal conductance remained uniform and low. Instantaneous water-use efficiency was much higher in droughted plants during the early morning and late evening, while during the middle of the day it was close to the value of irrigated plants. Net carbon gain in plants under drought reached 40% of the carbon gain in irrigated plants with a significant saving of water (80%). Average data derived from midday values of leaf CO2 assimilation rates and instantaneous water-use efficiency did not provide good estimates of the daily carbon gain and water-use efficiency for droughted leaves. Coupled with the morphological changes as a result of acclimation to progressive drought, modifications of diurnal patterns of leaf gas exchange rates effectively contribute to a sustained carbon gain during drought. These modifications significantly improve water-use efficiency, mainly by enabling the plant to take advantage of morning and evening hours with high air humidity.

scholarly journals Water relations of chives in function of salinity and circulation frequency of nutrient solutions

2019 ◽  
Vol 23 (5) ◽  
pp. 359-365 ◽  
Author(s):  
Fernando J. da Silva Júnior ◽  
José A. Santos Júnior ◽  
Manassés M. da Silva ◽  
Ênio F. de F. e Silva ◽  
Edivan R. de Souza
Keyword(s):  
Water Use Efficiency ◽  
Water Content ◽  
Water Use ◽  
Nutrient Solution ◽  
Water Consumption ◽  
Dry Matter ◽  
Saline Water ◽  
Dry Matter Partitioning ◽  
Use Efficiency ◽  
Supply Water

ABSTRACT Hydroponic cultivation using saline waters is an alternative for agricultural production, especially in the cultivation of vegetables. Therefore, the present work was conducted with the objective of evaluating the water consumption, water use efficiency and water content, as well as dry matter partitioning of chives (Allium schoenoprasum), cv. Todo Ano Evergreen – Nebuka exposed to six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 dS m-1), applied at two circulation frequencies (twice a day at 8 and 16 h; and three times a day - at 8, 12 and 16 h). The level in the nutrient solution reservoir, which decreased according to the water consumption by plants, was replaced with the respective saline water (Experiment I) and supply water (Experiment II). Both experiments used a completely randomized design, in a 6 x 2 factorial scheme, with five replicates. It was observed that increased circulation frequency and the use of supply water in the replacement mitigated the effects of salinity on water consumption, water use efficiency and water content in the plant. However, with the increase in nutrient solution electrical conductivity, dry matter allocation in the roots increased, to the detriment of the shoots.

Effect of water stress on growth, water use efficiency and gas exchange as related to osmotic adjustment of two halophytes Atriplex spp.

2013 ◽  
Vol 40 (5) ◽  
pp. 466 ◽  
Author(s):  
Oumelkheir Belkheiri ◽  
Maurizio Mulas
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Osmotic Adjustment ◽  
Late Summer ◽  
Field Capacity ◽  
Dry Weight ◽  
Co2 Assimilation ◽  
Effect Of Water ◽  
Use Efficiency

Atriplex halimus L. is known in the Mediterranean basin and along the coastal areas of Sardinia for its adaptability to salinity, although less information is available on the resistance of this species to water stress in absence of salinity. The effect of water stress on growth and water utilisation was investigated in two Atriplex species: A. halimus originating of south Sardinian island and the exotic species Atriplex nummularia Lindl., originating in Australia and widely used in land restoration of arid areas. Water stress was applied to young plants growing in 20 L pots with a sufficient water reserve to store a potentially sufficient water reserve to maintain substrate near to field capacity (30%) between irrigations. Watering was at 70% (control) or 40% (stress) of field capacity. In order to simulate the grazing by livestock, four plant biomass cuttings were conducted at times T0, T1, T2 and T3, corresponding to one cutting at the end of well watered phase (T0) before water stress induction, two cuttings after cycles of 5 weeks each during full summer (T1) and late summer (T2) and one cutting during autumn (T3). All plants remained alive until the end of treatment although growth was strongly reduced. Leaf dry weight (DW) and water use efficiency (WUE) were determined for all cuttings; relative water content (RWC), turgid weight : dry weight ratio (TW : DW), water potential (Ψw), osmotic potential (Ψs), CO2 assimilation, osmotic adjustment (OA), abscisic acid (ABA) and sugar accumulation were determined for the late summer cutting at T2. Water stress induced a decrease in DW, RWC, Ψw, Ψs, TW : DW and CO2 assimilation for both species, but an increase in WUE expressed in terms of dry matter production and a high accumulation of ABA and total sugars mainly for A. halimus. This suggests a more developed adaptive mechanism in this selection. Indeed, the clone was selected from the southern part of the island, where natural populations of saltbush are more exposed to abiotic stresses, mainly the water stress generated not by salinity. A. nummularia showed a greater OA and a positive net solute accumulation as than A. halimus, suggesting that water stress resistance in A. halimus is linked to a higher WUE rather than a greater osmotic adjustment.

Responses of CO2 Assimilation, Transpiration and Water Use Efficiency to Long-Term Elevated CO2 in Perennial C3 Xeric Loess Steppe Species

1996 ◽  
Vol 148 (3-4) ◽  
pp. 356-361 ◽  
Author(s):  
Zoltán Tuba ◽  
Kálmán Szente ◽  
Zoltán Nagy ◽  
Zsolt Csintalan ◽  
Judit Koch
Keyword(s):  
Water Use Efficiency ◽  
Elevated Co2 ◽  
Water Use ◽  
Co2 Assimilation ◽  
Steppe Species ◽  
Use Efficiency

scholarly journals Fertigation Strategies for Improving Water Use Efficiency and Limiting Nutrient Loss in Soilless Hippeastrum Production

HortScience ◽  
2016 ◽  
Vol 51 (6) ◽  
pp. 684-689 ◽  
Author(s):  
Youssef Rouphael ◽  
Giampaolo Raimondi ◽  
Rosanna Caputo ◽  
Stefania De Pascale
Keyword(s):  
Plant Growth ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Relations ◽  
Nutrient Solution ◽  
Nutrient Management ◽  
Growth Parameters ◽  
Management Strategies ◽  
Nutrient Loss ◽  
Use Efficiency

Implementing nutrient management strategies in soilless culture, which improve water use efficiency (WUE) and limit the loss of eutrophying elements without affecting crop performance, is a priority for the floriculture industry. The aim of the current research was to assess the effect of two nutrient management strategies, based on electrical conductivity (EC) or nitrate-nitrogen (N-NO3−) concentration control on plant growth, ornamental quality, plant–water relations, mineral composition, and WUE of greenhouse Hippeastrum grown in semiclosed soilless system. The recirculating nutrient solution was discharged whenever a threshold EC value of 3.0 dS·m−1 was reached (EC-based strategy), or when N-NO3− concentration decreased below the limit of 1.0 mol·m−3 (nitrate-based strategy). There were no significant differences in terms of plant growth parameters, stomatal resistance, leaf water relations, and macronutrient composition in plant tissues between the two nutrient management strategies. In the EC- and the nitrate-based strategies, the recirculating nutrient solution was flushed 10 and 5 times, respectively. The water loss (WL) and the total water use (Wuse) in the EC-based strategy were significantly higher by 261.1% and 61.5%, respectively, compared with the N-NO3−-based strategy. In contrast with the EC-based strategy, the adoption of the N-NO3−-based strategy significantly minimized the nitrate, phosphate, and potassium emissions to the environment. The effective WUE of the system (WUES) recorded in the N-NO3−-based strategy was higher by 55.9% compared with the one recorded with the EC-based strategy.

scholarly journals Strategies for Improved Yield and Water Use Efficiency of Lettuce (Lactuca sativa L.) through Simplified Soilless Cultivation under Semi-Arid Climate

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1379 ◽  
Author(s):  
Nicola Michelon ◽  
Giuseppina Pennisi ◽  
Nang Ohn Myint ◽  
Giacomo Dall’Olio ◽  
Lucrecia Pacheco Batista ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Nutrient Solution ◽  
Crop Production ◽  
Solution Concentration ◽  
Low Fertility ◽  
Small Areas ◽  
Soil Cultivation ◽  
Use Efficiency ◽  
Soilless Cultivation

Simplified soilless cultivation (SSC) systems have globally spread as growing solutions for low fertility soil regions, low availability of water irrigation, small areas and polluted environments. In the present study, four independent experiments were conducted for assessing the applicability of SSC in the northeast of Brazil (NE-Brazil) and the central dry zone of Myanmar (CDZ-Myanmar). In the first two experiments, the potentiality for lettuce crop production and water use efficiency (WUE) in an SSC system compared to traditional on-soil cultivation was addressed. Then, the definition of how main crop features (cultivar, nutrient solution concentration, system orientation and crop position) within the SSC system affect productivity was evidenced. The adoption of SSC improved yield (+35% and +72%, in NE-Brazil and CDZ-Myanmar) and WUE (7.7 and 2.7 times higher, in NE-Brazil and CDZ-Myanmar) as compared to traditional on-soil cultivation. In NE-Brazil, an eastern orientation of the system enabled achievement of higher yield for some selected lettuce cultivars. Furthermore, in both the considered contexts, a lower concentration of the nutrient solution (1.2 vs. 1.8 dS m−1) and an upper plant position within the SSC system enabled achievement of higher yield and WUE. The experiments validate the applicability of SSC technologies for lettuce cultivation in tropical areas.

Sign in / Sign up

Export Citation Format

Share Document