scholarly journals RESPOSTAS FISIOLÓGICAS E PRODUTIVAS DA PALMA DE ÓLEO IRRIGADA EM FASE INICIAL DE DESENVOLVIMENTO

Irriga ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 405-423 ◽  
Author(s):  
Jessica Lima Viana ◽  
Cornélio Alberto Zolin ◽  
Vanessa Quitete Ribeiro da Silva ◽  
Adilson Pacheco de Souza
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Soil Water ◽  
Water Deficit ◽  
Oil Palm ◽  
Irrigation Management ◽  
Fresh Mass ◽  
Soil Water Depletion ◽  
Mato Grosso ◽  
Water Depletion

RESPOSTAS FISIOLÓGICAS E PRODUTIVAS DA PALMA DE ÓLEO IRRIGADA EM FASE INICIAL DE DESENVOLVIMENTO     JESSICA LIMA VIANA1; CORNÉLIO ALBERTO ZOLIN2; VANESSA QUITETE RIBEIRO DA SILVA2 E ADILSON PACHECO DE SOUZA3   1 Programa de Pós-Graduação em Ciência do Solo, Universidade Federal do Paraná (UFPR), Rua dos Funcionários, 1540, Juvevê, CEP: 80035-050, Curitiba, Paraná, Brasil, [email protected]. 2 Pesquisador(a), Embrapa Agrossilvipastoril, Rodovia dos Pioneiros MT-222, Km 2,5, Zona Rural, Caixa Postal: 343, CEP: 78550-970, Sinop, Mato Grosso, Brasil, [email protected]; [email protected]. 3 Professor, Instituto de Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso (UFMT), Avenida Alexandre Ferronato, 1200, Cidade Jardim, CEP: 78550-728, Sinop, Mato Grosso, Brasil, [email protected].     1 RESUMO   Objetivou-se avaliar a taxa fotossintética, taxa de transpiração, condutância estomática e a eficiência do uso da água e a produtividade (número e massa fresca dos cachos por planta) de duas cultivares de palma de óleo irrigada, com 4 anos e 4 meses de idade, em Sinop-MT. O delineamento experimental adotado foi de blocos casualizados, sendo os tratamentos às disponibilidades de água no solo de 80%, 60%, 40%, 20% e 0% em parcelas subdivididas nas cultivares BRS C2501 e BRS C2528, com três repetições.  A palma de óleo foi sensível ao déficit hídrico apresentando alterações nas variáveis fisiológicas e redução no número e massa fresca dos cachos. A máxima taxa fotossintética da palma de óleo (A = 23,32 µmol m-2 s-1) foi obtida com 80% da disponibilidade de água no solo, independentemente da cultivar. As palmas de óleo sem irrigação submetidas a deficiência hídrica recuperam a taxa de fotossíntese, transpiração e condutância estomática no período chuvoso, indicando tolerância à deficiência hídrica e eficiência na regulação estomática.   Palavras-chave: déficit de pressão de vapor, Elaeais guineenses, manejo da irrigação, trocas gasosas.     VIANA, J. L.; ZOLIN, C. A.; SILVA, V. Q. R. da; SOUZA, A. P. de PHYSIOLOGICAL AND PRODUCTIVE RESPONSES OF IRRIGATED OIL PALM IN EARLY DEVELOPMENT PHASE     2 ABSTRACT   The aim of this study is to assess gas exchange (photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency) and yield characteristics (number and fresh mass of bunches) of oil palm under soil water depletion levels. This study was carried out in the experimental field of Embrapa Agrossilvi pastoril, in the north region of the state of Mato Grosso. The experimental design was randomized blocks in subdivided plots. Main plots consisted of five soil water depletion levels, respectively 80%, 60%, 40%, 20% and 0%. Subplots were represented by two cultivars (BRS C2501 and BRS C2528) with three replications. The oil palm was sensitive to water deficit presenting physiological changes and reduction in number and fresh mass of bunches. The maximum photosynthetic rate of oil palms was obtained with 80% of soil water depletion level (A = 23.32 μmol m-2 s-1), regardless of the cultivars. Plants under strong water deficit (without irrigation) recovered the rate of photosynthesis, transpiration and stomatal conductance in the rainy season, indicating tolerance to water deficit and efficiency in stomatal regulation.   Keywords: vapor pressure deficit, Elaeais guineenses, irrigation management, gas exchange.

scholarly journals Physiological Response of Carambola Trees to Soil Water Depletion in Krome Soils

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 857B-857
Author(s):  
Rashid Al-Yahyai* ◽  
Bruce Schaffer ◽  
Frederick S. Davies
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Stem Water Potential ◽  
Soil Water Depletion ◽  
Water Depletion ◽  
Loam Soil ◽  
Stem Water

The effect of soil water depletion on plant water potential and leaf gas exchange of carambola (Averrhoa carambola L. cv. Arkin) in Krome very gravelly loam soil was studied in an orchard and in containers in the field and in a greenhouse. The rate of soil water depletion was determined by continuously monitoring soil water content with multi-sensor capacitance probes. Stem water potential and leaf gas exchange of carambola in containers were reduced when the soil water depletion level fell below 50% (where field capacity = 100%). Although there was a decrease in the rate of soil water depletion in the orchard as the soil dried, soil water depletion did not go below an average of 70%. This was presumably due to sufficient rainfall and capillary movement of water in the soil. Therefore, soil water content did not decline sufficiently to affect leaf gas exchange and leaf and stem water potential of orchard trees. A decline in soil water depletion below 40% resulted in a concomitant decline in stem water potential of the container trees in the field and greenhouse to below -1.0 MPa. Stomatal conductance, net CO2 assimilation, and transpiration declined significantly when stem water potential was below -1.0 MPa. The reduction of net CO2 assimilation and transpiration was proportional to the decline in stomatal conductance of container trees in the field and greenhouse. Thus, soil water depletion in Krome very gravelly loam soil must be less than 50% before water potential or leaf gas exchange of carambola is affected. Based on these results, irrigation scheduling should be based on physiological variables such as stem water potential and stomatal conductance or the amount rather than the rate of soil water depletion.

scholarly journals Effects of soil water depletion on the water relations in tropical kudzu

1999 ◽  
Vol 34 (7) ◽  
pp. 1151-1157
Author(s):  
Adaucto Bellarmino de Pereira-Netto ◽  
Antonio Celso Novaes de Magalhães ◽  
Hilton Silveira Pinto
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Content ◽  
Soil Water ◽  
Cover Crop ◽  
Soil Water Depletion ◽  
Pueraria Phaseoloides ◽  
Water Depletion ◽  
Relative Water ◽  
Dry Soil

Tropical kudzu (Pueraria phaseoloides (Roxb.) Benth., Leguminosae: Faboideae) is native to the humid Southeastern Asia. Tropical kudzu has potential as a cover crop in regions subjected to dryness. The objective of this paper was to evaluate the effect of soil water depletion on leaflet relative water content (RWC), stomatal conductance (g) and temperature (T L) in tropical kudzu. RWC of waterstressed plants dropped from 96 to 78%, following a reduction in SWC from 0.25 to 0.17 g (H2O).g (dry soil)-1.Stomatal conductance of stressed plants decreased from 221 to 98 mmol.m-2.s-1, following the reduction in soil water content (SWC). The day after re-irrigation, g of water stressed plants was 15% lower than g of unstressed plants. Differences in T L between waterstressed and unstressed plants (deltaT L) rose linearly from 0.1 to 2.2ºC following progressive water deficit. RWC and T L of waterstressed plants paralled RWC and T L of unstressed plants the day after reirrigation. The strong decrease in SWC found in this study only induced moderate water stress in tropical kudzu. In addition, tropical kudzu recover rapidly from the induced water stress after the re-irrigation.

scholarly journals Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings

2007 ◽  
Vol 29 (2) ◽  
pp. 355-358 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Gas Exchange ◽  
Leaf Water ◽  
Soil Water Deficit ◽  
Stem Cuttings

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability. However, plants propagated by stem cuttings were unable to maintain a favorable internal water balance, reflecting negatively on stomatal conductance and leaf gas exchange. This fact is probably because umbu plants propagated by stem cuttings are not prone to formation of root tubers which are reservoirs for water and solutes. Thus, the establishing of umbu plants propagated by stem cuttings must be avoided in areas subjected to soil water deficit.

scholarly journals Physiological effects of water deficit on two oil palm (Elaeis guineensis Jacq.) genotypes

2015 ◽  
Vol 33 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Seyed Mehdi Jazayeri ◽  
Yurany Dayanna Rivera ◽  
Jhonatan Eduardo Camperos-Reyes ◽  
Hernán Mauricio Romero
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Oil Palm ◽  
Photosynthetic Capacity ◽  
Elaeis Guineensis ◽  
Leaf Water ◽  
Physiological Effects

Water supply is the main limiting factor that affects oil palm (Elaeis guineensis Jacq.) yield. This study aimed to evaluate the gas exchange and photosynthetic capacity, determine the physiological effects and assess the tolerance potential of oil palm genotypes under water-deficit conditions. The two oil palm commercial genotypes IRHO1001 and IRHO7010 were exposed to soil water potentials of -0.042 MPa (field capacity or well-watered) or -1.5 MPa (drought-stressed). The leaf water potential and gas exchange parameters, including photosynthesis, stomatal conductance, transpiration and water use efficiency (WUE), as well as the photosynthesis reduction rate were monitored at 4 and 8 weeks after treatment. The IRHO7010 genotype showed fewer photosynthesis changes and a smaller photosynthetic reduction under the prolonged water deficit conditions of 23% at 4 weeks after the treatment as compared to 53% at 8 weeks after treatment, but the IRHO1001 genotype showed 46% and 74% reduction at the two sampling times. 'IRHO7010' had a higher stomatal conductance and transpiration potential than 'IRHO1001' during the water shortage. The WUE and leaf water potential were not different between the genotypes during dehydration. The data suggested that 'IRHO7010' had a higher photosynthetic capacity during the drought stress and was more drought-tolerant than 'IRHO1001'.

scholarly journals Imaging plant responses to water deficit using electrical resistivity tomography

2020 ◽  
Vol 454 (1-2) ◽  
pp. 261-281 ◽  
Author(s):  
Sathyanarayan Rao ◽  
Nolwenn Lesparre ◽  
Adrián Flores-Orozco ◽  
Florian Wagner ◽  
Andreas Kemna ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Soil Water ◽  
Water Deficit ◽  
Water Uptake ◽  
White Clover ◽  
Electrical Resistivity Tomography ◽  
Root Water Uptake ◽  
Soil Water Depletion ◽  
Resistivity Tomography ◽  
Water Depletion

Abstract Background and aims Monitoring root water uptake dynamics under water deficit (WD) conditions in fields are crucial to assess plant drought tolerance. In this study, we investigate the ability of Electrical Resistivity Tomography (ERT) to capture specific soil water depletion induced by root water uptake. Methods A combination of surface and depth electrodes with a high spatial resolution (10 cm) was used to map 2-D changes of bulk soil electrical conductivity (EC) in an agronomic trial with different herbaceous species. A synthetic experiment was performed with a mechanistic model to assess the ability of the electrode configuration to discriminate abstraction patterns due to roots. The impact of root segments was incorporated in the forward electrical model using the power-law mixing model. Results The time-lapse analysis of the synthetic ERT experiment shows that different root water uptake patterns can be delineated for measurements collected under WD conditions but not under wet conditions. Three indices were found (depletion amount, maximum depth, and spread), which allow capturing plant-specific water signatures based moisture profile changes derived from EC profiles. When root electrical properties were incorporated in the synthetic experiments, it led to the wrong estimation of the amount of water depletion, but a correct ranking of plants depletion depth. When applied to the filed data, our indices showed that Cocksfoot and Ryegrass had shallower soil water depletion zones than white clover and white clover combined with Ryegrass. However, in terms of water depletion amount, Cocksfoot consumed the largest amount of water, followed by White Clover, Ryegrass+White Clover mixture, and Ryegrass. Conclusion ERT is a well-suited method for phenotyping root water uptake ability in field trials under WD conditions.

scholarly journals Effects of water deficit in two phenological stages on production of japanese cucumber cultived in greenhouse

2011 ◽  
Vol 31 (4) ◽  
pp. 676-686 ◽  
Author(s):  
Eduardo C. Oliveira ◽  
Jacinto de A. Carvalho ◽  
Wellington G. da Silva ◽  
Fátima C. Rezende ◽  
Willian F. de Almeida
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Irrigation Management ◽  
Soil Water Potential ◽  
Phenological Stages ◽  
Cucumis Sativus L ◽  
Randomized Design ◽  
Minas Gerais State ◽  
Engineering Department ◽  
Four Levels

The experiment was performed in the experimental area of the Engineering Department Federal University of Lavras, Minas Gerais State, Brazil. It aimed at identifying the adequate irrigation management of the greenhouse-cultivated Japanese cucumber (Cucumis sativus L.). complete randomized design, with four levels of soil water potential (15; 30; 60 e 120 kPa) at two phenological phases (vegetative and reproductive), and 5 replications. Overall, the results showed decrease of yield according to increase of soil water potentials. During the reproductive stage, Japanese cucumber plants were more sensitive to water deficit, resulting in further decrease in yield compared to applied water deficit during the vegetative stage of the culture.

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