Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

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The influence of water stress on plant hydraulics, gas exchange, berry composition and quality of Pinot Noir wines in Switzerland

OENO One ◽

10.20870/oeno-one.2017.51.1.1314 ◽

2017 ◽

Vol 51 (1) ◽

Cited By ~ 10

Author(s):

Vivian Zufferey ◽

Jean-Laurent Spring ◽

Thibaut Verdenal ◽

Agnès Dienes ◽

Sandrine Belcher ◽

...

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Leaf Gas Exchange ◽

Water Status ◽

Growing Season ◽

Pinot Noir ◽

Wine Quality ◽

Plant Hydraulics ◽

Berry Composition

Aims : The aims of this study were to investigate the physiological behavior (plant hydraulics, gas exchange) of the cultivar Pinot Noir in the field under progressively increasing conditions of water stress and analyze the effects of drought on grape and wine quality.Methods and results : Grapevines of the variety Vitis vinifera L. cv. Pinot Noir (clone 9-18, grafted onto 5BB) were subjected to different water regimes (irrigation treatments) over the growing season. Physiological indicators were used to monitor plant water status (leaf and stem water potentials and relative carbon isotope composition (d13C) in must sugars). Leaf gas exchange (net photosynthesis A and transpiration E), leaf stomatal conductance (gs), specific hydraulic conductivity in petioles (Kpetiole), yield components, berry composition at harvest, and organoleptic quality of wines were analyzed over a 7-year period, between 2009 and 2015, under relatively dry conditions in the canton of Wallis, Switzerland. A progressively increasing water deficit, observed throughout the season, reduced the leaf gas exchange (A and E) and gs in non-irrigated vines. The intrinsic water use efficiency (WUEi, A/gs) increased during the growing season and was greater in water-stressed vines than in well-watered vines (irrigated vines). This rise in WUEi was correlated with an increase in d13C in must sugars at harvest. Drought led to decreases in Kpetiole, E and sap flow in stems. A decrease in vine plant vigor was observed in vines that had been subjected to water deficits year after year. Moderate water stress during ripening favored sugar accumulation in berries and caused a reduction in total acidic and malic contents in must and available nitrogen content (YAN). Wines produced from water-stressed vines had a deeper color and were richer in anthocyanins and phenol compounds compared with wines from well-watered vines with no water stress. The vine water status greatly influenced the organoleptic quality of the resulting wines. Wines made from non-irrigated vines with a water deficit presented more structure and higher-quality tannins. They were also judged to be more full-bodied and with blended tannins than those made from irrigated vines.Conclusions : Grape ripening and resulting Pinot Noir wines were found to be largely dependent on the water supply conditions of the vines during the growing season, which influenced gas exchange and plant hydraulics.Significance and impact of the study : Plant water status constitutes a key factor in leaf gas exchange, canopy water use efficiency, berry composition and wine quality.

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A comparison of seasonal patterns of photosynthate production and use in branches of red spruce saplings at two elevations

Canadian Journal of Forest Research ◽

10.1139/x91-061 ◽

1991 ◽

Vol 21 (4) ◽

pp. 455-461 ◽

Cited By ~ 6

Author(s):

Christian P. Andersen ◽

Samuel B. McLaughlin ◽

W. Kelly Roy

Keyword(s):

Carbon Assimilation ◽

Growing Season ◽

Red Spruce ◽

Seasonal Patterns ◽

Sink Strength ◽

Great Smoky Mountains ◽

Sink Activity ◽

Lower Elevation ◽

Branch Biomass ◽

High Elevations

Seasonal patterns of carbon transport from 14C-labeled foliage were examined in red spruce (Picearubens Sarg.) branches at 1935 and 1720 m elevations in the Great Smoky Mountains National Park to characterize possible physiological mechanisms underlying the observed reductions in growth at high elevations. Current and 1-year-old foliage was labeled on 5- to 7-year-old branches of sapling-sized trees in June, August, and October. Retention of 14C was measured after 24 h, and allocation to other branch segments was characterized after 7 days. Total 14C-labeled carbon assimilation was greater in current than in 1-year-old foliage throughout the growing season. This suggests that photosynthetic capacity is high in developing foliage prior to needle maturity and remains high during the first growing season. In August, 14C retention in labeled foliage was less at the higher than at the lower elevation site, possibly reflecting increased respiratory losses that had been previously reported at the higher site. Retention of 14C in current-year shoots as a percent of 14C remaining after 7 days, a measure of sink strength, was high at both sites in June and remained high throughout the season in current-year shoots at the higher elevation site. The relatively high sink activity coupled with the large apportionment of biomass to current-year shoots (19.9 and 26.7% of total branch biomass at the lower and higher elevation sites, respectively) may make red spruce particularly susceptible to stresses such as winter injury that affect young foliage. In addition, the relatively greater sink activity of current-year shoots at the higher elevation site in August and October suggests that the contribution of current-year foliage to overall tree growth may be less at the higher than at the lower elevation site.

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The influence of vine water regime on the leaf gas exchange, berry composition and wine quality of Arvine grapes in Switzerland

OENO One ◽

10.20870/oeno-one.2020.54.3.3106 ◽

2020 ◽

Vol 54 (3) ◽

pp. 553-568

Author(s):

Vivian Zufferey ◽

Thibaut Verdenal ◽

Agnès Dienes ◽

Sandrine Belcher ◽

Fabrice Lorenzini ◽

...

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Leaf Gas Exchange ◽

Water Status ◽

Growing Season ◽

Available Nitrogen ◽

Water Regimes ◽

Sensorial Quality ◽

Berry Composition

Aims: The aim of the present study was to analyse the impact of different water regimes on the physiological and agronomical behavior of an aromatic white grapevine (cv. Arvine) by means of various levels of irrigation. The consequences of the plant water status were evaluated by carrying out a chemical (aromatic precursors) and sensorial analysis of the resulting wines.Methods and results: Adult vines of Vitis vinifera L. cv. Arvine grafted onto 5BB were subjected to different water regimes (various levels of irrigation) during the growing season. Physiological indicators were used to monitor the plant water status [pre-dawn leaf (ΨPD) and stem (ΨSTEM) water potentials and carbon isotope composition (d13C) in the must]. Gas exchange (net photosynthesis AN and transpiration E), stomatal conductance (gs), yield parameters, berry composition at harvest, analysis of potential grape aromatic properties (glycosyl-glucose G-G, precursor 3-mercaptohexanol P 3-MH) and the sensorial quality of wines were analysed over a period of 8 consecutive years (2009-2016) in the Agroscope experimental vineyard in Leytron under the relatively dry conditions of the Rhône valley in Wallis, Switzerland.In the non-irrigated vines, the progressively increasing water deficit observed over the season reduced the leaf gas exchange (AN and E) and gs. The intrinsic water use efficiency (WUEi, A/gs) increased over the season and was greater in the vines that had suffered water restriction than in the irrigated vines. The rise in WUEi was correlated with an increase in d13C in the must sugars at harvest. A decrease in plant vigor was observed in the water stressed vines over multiple years. Moderate to high water stress during fruit ripening lowered the contents of total and malic acidity in the musts and the content of yeast available nitrogen (YAN). On the other hand, contents in sugar and the aromatic precursor (P-3MH) in berries were not influenced by the vine water status. The G-G values for berries increased with rising water stress in the non-irrigated vines. The wines from the plants subjected to water stress and to yeast available nitrogen deficiency (non-irrigated vines during hot and dry seasons) had a less distinctive typicity, and developed a lower aromatic expression with a more bitter taste, than the wines from the non-stressed plants. Overall, and compared with the stressed vines, the organoleptic characteristics and quality of Arvine wines from vines which had not undergone restrictions in water and nitrogen during the growing season were appreciated more.Conclusions: The vine’s physiological behavior (leaf gas exchange, plant vigor) and agronomic parameters (yield, berry composition), together with the quality of white aromatic Arvine wines, were strongly influenced by vine water regimes during the growing season.Significance and impact of the study: Vine water status and must nitrogen contents are key factors in grape composition and in the sensorial quality of resulting aromatic white wines.

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Morphophysiological aspects of ornamental sunflowers cultivated in different growing seasons under semi-arid conditions

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v26n4p299-305 ◽

2022 ◽

Vol 26 (4) ◽

pp. 299-305

Author(s):

Sheila D. P. da Silva ◽

Gracielle P. de Souza ◽

Agnaldo R. de M. Chaves ◽

Marcelle A. da Silva ◽

Rafaela R. de Souza ◽

...

Keyword(s):

Gas Exchange ◽

Arid Regions ◽

Block Design ◽

Growing Season ◽

Climatic Conditions ◽

Growing Seasons ◽

Arid Conditions ◽

Randomized Block Design ◽

Leaf Surface Area ◽

Semi Arid

ABSTRACT Knowledge of how climatic conditions affect plant morphophysiology is essential for understanding how to manage the growth cycles of different crops. The aim of this study was to evaluate the effects of the growing seasons in a semi-arid area on the morphophysiological variables of ornamental sunflower plants. The experiment was carried out in a randomized block design in a split-plot arrangement with four replicates. Six cultivars (‘Bonito de Outono Sortido’, ‘Sol Noturno’, ‘Sol Vermelho’, ‘Jardim Amarelo Alto’, ‘Girassol F1 Sunbright Supreme’ and ‘Girassol F1 Vincents Choice’) were evaluated in the main plots and two different growing seasons (GS) in the subplots (GS1 - warm climate and GS2 - mild climate). Evaluations of gas exchange, chlorophyll indices, and leaf surface area were carried out at the reproductive stage (R5.5). The cultivation of ornamental sunflowers in semi-arid regions was significantly affected by the growing season. Changes in gas exchange variables and the morphophysiology of ornamental sunflower plants in the two growing seasons reflected the high phenotypic plasticity characteristic of this species. The cultivation of ornamental sunflowers under semi-arid conditions in the growing season, when air temperature and solar radiation are high, could be limited due to elevated transpiration rates. Therefore, it is recommended that they are grown mainly during the moderate climatic season in semi-arid regions.

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A Whole-plant, Open, Gas-exchange System for Measuring Net Photosynthesis of Potted Woody Plants

HortScience ◽

10.21273/hortsci.31.6.944 ◽

1996 ◽

Vol 31 (6) ◽

pp. 944-946 ◽

Cited By ~ 12

Author(s):

D.P. Miller ◽

G.S. Howell ◽

J.A. Flore

Keyword(s):

Gas Exchange ◽

Photosynthetically Active Radiation ◽

Woody Plants ◽

Net Photosynthesis ◽

Growing Season ◽

Exchange System ◽

Active Radiation ◽

Whole Plant ◽

Short Period ◽

Gas Exchange System

Chambers were constructed to measure gas exchange of entire potted grapevines (Vitis vinifera L.). The plant enclosures were constructed from Mylar film, which is nearly transparent to photosynthetically active radiation. Maintaining a slight, positive, internal pressure allowed the Mylar chambers to inflate like balloons and required no other means of support. The whole-plant, gas-exchange chamber design and construction were simple and inexpensive. They were assembled easily, equilibrated quickly, and did not require cooling. They allowed for the measurement of many plants in a relatively short period. This system would enable the researcher to make replicated comparisons of treatment influences on whole-plant CO2 assimilation throughout the growing season. While CO2 measurement was the focus of this project, it would be possible to measure whole-plant transpiration with this system.

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Estimating Growing Season Evapotranspiration and Transpiration of Major Crops over a Large Irrigation District from HJ-1A/1B Data Using a Remote Sensing-Based Dual Source Evapotranspiration Model

Remote Sensing ◽

10.3390/rs12050865 ◽

2020 ◽

Vol 12 (5) ◽

pp. 865

Author(s):

Bing Yu ◽

Songhao Shang

Keyword(s):

Remote Sensing ◽

Water Stress ◽

Water Consumption ◽

Irrigation Water ◽

Growing Season ◽

Irrigation District ◽

Planting Density ◽

Growing Seasons ◽

Dual Source ◽

Crop Planting

Crop evapotranspiration (ET) is the largest water consumer of agriculture water in an irrigation district. Remote sensing (RS) technique has provided an effective way to map regional ET using various RS-based ET models over the past several decades. To map growing season ET of different crops and partition ET into evaporation (E) and transpiration (T) at regional scale, appropriate ET models should be further integrated with crop distribution maps in different years and crop growing seasons determined for each crop pixel. In this study, a hybrid dual-source scheme and trapezoid framework-based ET Model (HTEM) fed with HJ-1A/1B data was applied in Hetao Irrigation District (HID) of China from 2009 to 2015 to map crop growing season ET and T at 30 m resolution. The HTEM model with HJ-1A/1B data performed well in estimating ET in HID, and the finer spatial resolution of model input data can improve the estimation accuracy of ET. Combined with the annual crop planting map identified in previous study, and crop growing seasons determined from fitted Normalized Difference Vegetation Index (NDVI) curves for crop pixels, the spatial and temporal variations of growing season ET and T of major crops (maize and sunflower) were examined. The results indicate that ET and T of maize and sunflower reach their minimum values in the southwest HID with smaller crop planting density, and reach their maximum values in northwest HID with higher crop planting density. Over the study period with a decreasing trend of available irrigation water, ET and T in maize and sunflower growing seasons show decreasing trends, while ratios of T/ET show increasing trends, which implies that the adverse effect of decreased irrigation water diversion on crop growth is diminished due to the favorable portioning of E and T in cropland of HID. In addition, the calculation results of crop coefficients show that there is water stress to crop growth in the study area. The present results are helpful to better understand the spatial pattern of crop water consumption and water stress of different crops during crop growing season, and provide the basis for optimizing the spatial distribution of crop planting with less water consumption and more crop yield.

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Crop water stress maps for entire growing seasons from visible and thermal UAV imagery

10.5194/bg-2016-316 ◽

2016 ◽

Cited By ~ 2

Author(s):

Helene Hoffmann ◽

Rasmus Jensen ◽

Anton Thomsen ◽

Hector Nieto ◽

Jesper Rasmussen ◽

...

Keyword(s):

Water Stress ◽

Air Temperature ◽

Land Surface ◽

Surface Air Temperature ◽

Growing Season ◽

Color Images ◽

Crop Water ◽

Crop Water Stress Index ◽

Growing Seasons ◽

Crop Water Stress

Abstract. This study investigates whether a Water Deficit Index (WDI) based on imagery from Unmanned Aerial Vehicles (UAVs) can provide accurate crop water stress maps at different growth stages of barley and in differing weather situations. Data from both the early and the late growing season are included to investigate whether the WDI index has the unique potential to be applicable both when the land surface is partly composed of bare soil and when crops on the land surface are senescing. The WDI index differs from the more commonly applied Crop Water Stress Index (CWSI) in that it uses both a spectral vegetation index (VI), to determine the degree of surface greenness, and the composite land surface temperature (LST) (not solely canopy temperature). Lightweight thermal and RGB (Red-Green-Blue) cameras were mounted on a UAV on three occasions during the growing season, 2014, and provided composite LST and color images, respectively. From the LST, maps of surface-air temperature differences were computed. From the color images, the Normalized Green-Red Difference Index (NGRDI), constituting the indicator of surface greenness, was computed. Advantages of the WDI as an irrigation map, as compared with simpler maps of the surface-air temperature difference, are discussed, and the suitability of the NGRDI index is assessed. Final WDI maps had a spatial resolution of 0.25 m. It was found that the UAV-based WDI index determines accurate crop water status. Further, the WDI index is especially valuable in the late growing season because at this stage the remote sensing data represent crop water availability to a greater extent than they do in the early growing season, and because the WDI index accounts for areas of ripe crops that no longer have the same need of irrigation. WDI maps can potentially serve as water stress maps, showing the farmer where irrigation is needed to ensure healthy growing plants, during entire growing seasons.

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Photosynthetic responses to chromosome doubling in relation to leaf anatomy in Lonicera japonica subjected to water stress

Functional Plant Biology ◽

10.1071/fp09022 ◽

2009 ◽

Vol 36 (9) ◽

pp. 783 ◽

Cited By ~ 48

Author(s):

Wei-Dong Li ◽

Dilip K. Biswas ◽

Hong Xu ◽

Chang-Qing Xu ◽

Xian-Zhong Wang ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Water Stress ◽

Gas Exchange ◽

Chromosome Doubling ◽

Starch Content ◽

Soluble Sugars ◽

Net Photosynthesis ◽

Lonicera Japonica ◽

Photochemical Quenching ◽

Effective Quantum Yield

Gas exchange, chlorophyll fluorescence, and contents of some metabolites in two Japanese honeysuckle (Lonicera japonica Thunb.) cultivars, Damaohua (2n = 2x) and Jiufengyihao (2n = 4x), were compared with explore the function of chromosome doubling under water stress conditions. Water stress significantly decreased net photosynthesis rate, stomatal conductance, and transpiration rate of both cultivars. It also decreased electron transport rate, effective quantum yield of Photosystem II, photochemical quenching, and starch content, but increased non-photochemical quenching and contents of total soluble sugars, proline, and malondialdehyde. However, the tetraploid cultivar showed higher resistance to water stress than the diploid, as indicated by the fact that gas exchange, chlorophyll fluorescence, and metabolites were less affected for the tetraploid than the diploid. Moreover, the tetraploid recovered more quickly than the diploid after re-watering. Morphological and anatomical analysis further revealed that the tetraploid possessed less whole plant leaf area, higher leaf mass per unit area, thicker epidermis (both upper and lower) and palisade tissue, as well as denser pubescence. All of those specialised structures caused by chromosome doubling might lead to greater capacity in coping with drought stress. Our findings suggest that the effect of chromosome doubling on drought resistance in L. japonica could attribute to the improvement of structure and photosynthesis-related traits.

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Ecophysiology ofpotentilla gracilisdouglas ex hook (rosaceae): effects of night temperature and water stress on photosynthetic gas exchange

10.1101/685727 ◽

2019 ◽

Author(s):

Madhav P. Nepal ◽

Virginia S. Berg

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Gas Exchange ◽

Light Intensity ◽

Light Response ◽

Growing Season ◽

Night Temperature ◽

Response Curves ◽

Photosynthetic Gas Exchange ◽

Light Response Curves

ABSTRACTPlants in stressful environments have evolved strategies to cope with fluctuating environmental conditions.Potentilla gracilis, also known as Alpine Cinquefoil, grows in alpine meadows of the Rocky Mountains (USA), and is subjected to wide ranges of temperature, light intensity and water availability on a time scale of minutes to days during the growing season. Leaves often freeze to a brittle state at night, are exposed to high radiation while still frosty, dehydrate to wilting during the following light period, and then repeat the cycle the following day. The main objective of this research was to determine the effect of night temperature on subsequent photosynthetic gas exchange inP. gracilis. We used a photosynthetic gas exchange system to compare assimilation and stomatal conductance from light response curves of cold-acclimatedP. gracilisfollowing warm and chilling nights, and for plants at different water potentials. From the light response curves, dark respiration, light compensation point, maximum assimilation, light saturation point, and inhibition of photosynthesis were determined and were compared among the same plants under varying conditions. Assimilation and stomatal conductance decreased with the fall in measurement temperature, following chilling nights, and with the severity of water stress. Low night temperature and high photon flux density during the daytime, which are very common during the growing season in the field, cause a reduction in photosynthesis of the plant. The probable underlying damage during inhibition is likely repairable indicating protection rather than damage. The cold nocturnal temperature, with its less efficient biochemical repair capabilities, may partly be responsible for the reduction in assimilation of the following day.P. gracilisspecies exhibited persistent acquired freezing tolerance; substantial photosynthetic productivity over a wide range of light intensity and temperature; and significant tolerance of, and rapid recovery from, severe drought; making a maximum use of often challenging resources.

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FISIOLOGIA DO Sesamum indicum L. SOB ESTRESSE HÍDRICO E APLICAÇÃO DE ÁCIDO SALICÍLICO1

Irriga ◽

10.15809/irriga.2016v21n4p711-723 ◽

2016 ◽

Vol 21 (4) ◽

pp. 711-723

Author(s):

Selma Dos Santos Feitosa ◽

Manoel Bandeira de Albuquerque ◽

Ademar Pereira de Oliveira ◽

Walter Esfrain Pereira ◽

José Félix de Brito Neto

Keyword(s):

Salicylic Acid ◽

Water Stress ◽

Gas Exchange ◽

Hormonal Treatment ◽

Net Photosynthesis ◽

Sesamum Indicum ◽

Leaf Temperature ◽

Leaf Water Content ◽

Water Treatments ◽

As Effects

FISIOLOGIA DO Sesamum indicum L. SOB ESTRESSE HÍDRICO E APLICAÇÃO DE ÁCIDO SALICÍLICO1 SELMA DOS SANTOS FEITOSA2; MANOEL BANDEIRA DE ALBUQUERQUE3; ADEMAR PEREIRA DE OLIVEIRA3; WALTER ESFRAIN PEREIRA3 E JOSÉ FÉLIX DE BRITO NETO4 1Trabalho de Tese de Doutorado do primeiro autor2Departamento de Agroecologia, IFPB, Rua Pedro Antunes, s/nº, 58814-000, São Gonçalo, Sousa, Paraíba, Brasil, email: [email protected] de Fitotecnia e Ciências Ambientais, CCA/UFPB, Rodovia BR 079, Km 12, 58397-000, Areia, Paraíba, Brasil, email: [email protected], [email protected], [email protected] de Agroecologia e Agropecuária, CCAA/UEPB, Sítio Imbaúba, s/nº, Zona Rural, 58117-000, Lagoa Seca, Paraíba, Brasil, email: [email protected] 1 RESUMO Objetivou-se verificar o comportamento fisiológico do Sesamum indicum submetido ao estresse hídrico e aplicação de ácido salicílico (AS), realizado sob o delineamento em blocos ao acaso num fatorial 4 × 2, sendo, 0, 4, 8 e 12 mg L-1 de ácido salicílico (AS) e dois tratamentos hídricos (com e sem suspensão hídrica por oito dias). Foram semeadas 10 sementes por vaso e aos 30 dias após a emergência (DAE) aplicados os tratamentos. As trocas gasosas e o teor relativo de água foliar (TRA) foram realizados no oitavo dia de deficiência hídrica e da aplicação do tratamento hormonal e 48 horas após a retomada da rega. Para as variáveis de trocas gasosas verificaram-se diferenças no oitavo dia da suspensão da rega e após a reidratação para o fator estresse, enquanto, para os efeitos do AS apenas a variável temperatura foliar (Tf) a interação foi significativa. A fotossíntese (A) foi 70% inferior sob suspensão da rega e à medida que se elevou a concentração de AS, enquanto o TRA foi significativo apenas para os efeitos do estresse. O estresse hídrico alterou o comportamento da fotossíntese líquida, condutância estomática, transpiração e temperatura foliar. Palavras-chave: Trocas gasosas; Relações hídricas; Fitohormônio; Oleaginosa. FEITOSA, S. S.; ALBUQUERQUE, M. B.; OLIVEIRA, A. P.; PEREIRA, W. E.; BRITO NETO, J. F.PHYSIOLOGY OF Sesamum indicum L. UNDER WATER STRESS AND SALICYLIC ACID APPLICATION 2 ABSTRACT This study aimed at verifying the physiological behavior of Sesamum indicum subjected to water stress and application of salicylic acid (SA), held under the design of randomized blocks in a factorial 4 × 2, and 0, 4, 8 and 12 mg L-1 salicylic acid (SA) and two water treatments (with and without water suspension for eight days). 10 seeds per pot were planted and 30 days after emergence (DAE) the treatments were applied. Gas exchange and the relative leaf water content (TRA) were assessed on the eighth day of water deficiency and the application of hormonal treatment and 48 hours after the resumption of watering. For gas exchange variables there were differences in the eighth day of watering suspension and after rehydration for the stress factor, while, for the AS effects only in the variable leaf temperature (Tf) interaction was significant. Photosynthesis (A) was 70% lower than under suspension of irrigation and the concentration of AS increased, while TRA was significant only for the effects of stress. Water stress altered the behavior of net photosynthesis, stomatal conductance, transpiration and leaf temperature. Keywords: Gas exchange; Water relations; Phytohormone; Oleaginous.

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