APPLE LEAF GAS EXCHANGE MEASUREMENTS IN 'BROOKFIELD GALA' TREES UNDER THREE WATER AND NUTRIENT MANAGEMENT STRATEGIES

2008 ◽  
pp. 41-49
Author(s):  
T.C. Lebese ◽  
S.J.E. Wand ◽  
P.J.C. Stassen
Irriga ◽  
2018 ◽  
Vol 22 (1) ◽  
pp. 129-139
Author(s):  
Antônia Leila Rocha Neves ◽  
Claudivan Feitosa de Lacerda ◽  
Mailson Pereira Alves ◽  
Carlos Henrique Carvalho de Sousa ◽  
Enéas Gomes Filho

LEAF GAS EXCHANGE AND NUTRIENTS ACCUMULATION IN COWPEA PLANTS UNDER DIFFERENT MANAGEMENT STRATEGIES WITH BRACKISH WATER  ANTÔNIA LEILA ROCHA NEVES1; CLAUDIVAN FEITOSA DE LACERDA2; MAILSON PEREIRA ALVES3; CARLOS HENRIQUE CARVALHO DE SOUSA4 E ENÉAS GOMES FILHO5 1Doutora em Engenharia Agrícola, Universidade Federal do Ceará (UFC), Campus do Pici, Bloco 804, Fortaleza, Ceará, CEP: 60.455-760. [email protected] do Departamento de Engenharia Agrícola, Universidade Federal do Ceará (UFC), Campus do Pici, Bloco 804, Fortaleza, Ceará, CEP: 60.455-760. [email protected]ônomo, Universidade Federal do Ceará (UFC), Campus do Pici, Bloco 804, Fortaleza, Ceará, CEP: 60.455-760. [email protected] em Engenharia Agrícola, Universidade Federal do Ceará (UFC), Campus do Pici, Bloco 804, Fortaleza, Ceará, CEP: 60.455-760. [email protected] do Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará (UFC), Campus do Pici, Bloco 907, Fortaleza, Ceará. [email protected]  1 ABSTRACT Many studies have shown that the use of strategies for the management of saline water in irrigation reduces impacts on the soil and crops. We aimed to evaluate the effect of management strategies of irrigation with brackish water on leaf gas exchange and mineral concentrations of cowpea (Vigna unguiculata L.Walp.). The experiment was conducted in randomized blocks with thirteen treatments and five replications. The treatments consisted of: T1 (control), T2, T3 and T4 using water of 0.5 (A1), 2.2 (A2), 3.6 (A3) and 5.0 (A4) dS m-1, respectively, during the entire crop cycle; T5, T6 and T7,  use of A2, A3 and A4 water, respectively, only in the flowering and fructification stage of the crop cycle; using different water in a cyclic way, six irrigations with A1 followed by six irrigations with A2 (T8), A3 (T9) and A4, (T10), respectively; T11, T12 and T13, using water A2, A3 and A4, respectively, starting  at 11 days after planting (DAP) and continuing until the end of the crop cycle. Continuous application of the high salinity water (above 3.6 dS m-1) over the whole cycle of cowpea inhibits leaf gas exchange, being stomatal conductance the most sensitive variable. The alternate use of brackish water or only in the salt tolerant growth stage reduces the accumulation of potentially toxic ions (especially chloride) and maintains the similar values of leaf gas exchange and total essential nutrients ( K, Ca and Mg) extracted by plants, in relation to plants irrigated with canal water (low salinity). Index terms: Salt stress, irrigation, stomatal conductance, photosynthesis, transpiration.  NEVES, A. L. R.; LACERDA, C. F.; ALVES, M. P.; SOUSA, C. H. C.; GOMES FILHO, E.TROCAS GASOSAS  FOLIARES E ACUMULAÇÃO DE NUTRIENTES EM PLANTAS  DE FEIJÃO-CAUPI SOB DIFERENTES ESTRATÉGIAS DE MANEJO DE IRRIGAÇÃO COM ÁGUAS SALOBRAS 2 RESUMO Muitos estudos têm mostrado que a utilização de estratégias para o manejo de águas salobras na irrigação reduz os impactos sobre o solo e as culturas. Objetivou-se avaliar o efeito de estratégias de manejo de irrigação com água salobra sobre as trocas gasosas foliares e os teores de íons em feijão-caupi (Vigna unguiculata L.Walp.). O experimento foi conduzido em blocos ao acaso com treze tratamentos e cinco repetições. Os tratamentos consistiram de: T1 (controle), T2, T3 e T4, utilizando água de 0,5 (A1), 2,2 (A2), 3,6 (A3) e 5,0 (A4) dS m-1, respectivamente, ao longo de todo o ciclo da cultura; T5, T6 e T7, utilizando águas salinas A2, A3 e A4, respectivamente, apenas na fase de floração e frutificação; uso de diferentes fontes de água de forma cíclica, com seis irrigações com A1 seguido por seis irrigações com A2 (T8), A3 (T9) e A4 (T10), respectivamente; T11, T12 e T13, usando água A2, A3 e A4, respectivamente, a partir de 11 dias após o plantio (DAP) e continuando até ao final do ciclo da cultura. A aplicação contínua de água de elevada salinidade (acima de 3,6 dS m-1) ao longo do ciclo do feijão-caupi inibe as trocas gasosas foliares, sendo a condutância estomática a variável mais sensível. O uso alternado de água salobra ou apenas na fase de maior tolerância da cultura do feijão-caupi reduz o acúmulo de íons potencialmente tóxicos (especialmente o cloreto) e mantém os valores de trocas gasosas foliares e dos totais de nutrientes essenciais (K, Ca e Mg) extraídos pela cultura similares aos das plantas irrigadas apenas com água do canal (baixa salinidade). Palavras-chave: Estresse salino, irrigação, condutância estomática, fotossíntese, transpiração. 


2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.


2015 ◽  
Vol 38 (8) ◽  
pp. 1503-1513 ◽  
Author(s):  
THORSTEN KNIPFER ◽  
ASHLEY EUSTIS ◽  
CRAIG BRODERSEN ◽  
ANDREW M. WALKER ◽  
ANDREW J. MCELRONE

Nature Plants ◽  
2021 ◽  
Author(s):  
Diego A. Márquez ◽  
Hilary Stuart-Williams ◽  
Graham D. Farquhar

2021 ◽  
Vol 128 ◽  
pp. 126308
Author(s):  
João William Bossolani ◽  
Carlos Alexandre Costa Crusciol ◽  
José Roberto Portugal ◽  
Luiz Gustavo Moretti ◽  
Ariani Garcia ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 608
Author(s):  
Fairuz Fatini Mohd Yusof ◽  
Jamilah Syafawati Yaacob ◽  
Normaniza Osman ◽  
Mohd Hafiz Ibrahim ◽  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
...  

The growing demand for high value aromatic herb Polygonum minus-based products have increased in recent years, for its antioxidant, anticancer, antimicrobial, and anti-inflammatory potentials. Although few reports have indicated the chemical profiles and antioxidative effects of Polygonum minus, no study has been conducted to assess the benefits of micro-environmental manipulation (different shading levels) on the growth, leaf gas exchange and secondary metabolites in Polygonum minus. Therefore, two shading levels (50%:T2 and 70%:T3) and one absolute control (0%:T1) were studied under eight weeks and 16 weeks of exposures on Polygonum minus after two weeks. It was found that P. minus under T2 obtained the highest photosynthesis rate (14.892 µmol CO2 m−2 s−1), followed by T3 = T1. The increase in photosynthesis rate was contributed by the enhancement of the leaf pigments content (chlorophyll a and chlorophyll b). This was shown by the positive significant correlations observed between photosynthesis rate with chlorophyll a (r2 = 0.536; p ≤ 0.05) and chlorophyll b (r2 = 0.540; p ≤ 0.05). As the shading levels and time interval increased, the production of total anthocyanin content (TAC) and antioxidant properties of Ferric Reducing Antioxidant Power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) also increased. The total phenolic content (TPC) and total flavonoid content (TFC) were also significantly enhanced under T2 and T3. The current study suggested that P.minus induce the production of more leaf pigments and secondary metabolites as their special adaptation mechanism under low light condition. Although the biomass was affected under low light, the purpose of conducting the study to boost the bioactive properties in Polygonum minus has been fulfilled by 50% shading under 16 weeks’ exposure.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.


Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 663
Author(s):  
James Bunce

Attempts to identify crop genetic material with larger growth stimulation at projected elevated atmospheric CO2 concentrations are becoming more common. The probability of reductions in photosynthesis and yield caused by short-term variation in CO2 concentration within elevated CO2 treatments in the free-air CO2 enrichment plots raises the question of whether similar effects occur in glasshouse or indoor chamber experiments. These experiments were designed to test whether even the normal, modest, cyclic variation in CO2 concentration typical of indoor exposure systems have persistent impacts on photosynthesis and growth, and to explore mechanisms underlying the responses observed. Wheat, cotton, soybeans, and rice were grown from seed in indoor chambers at a mean CO2 concentration of 560 μmol mol−1, with “triangular” cyclic variation with standard deviations of either 4.5 or 18.0 μmol mol−1 measured with 0.1 s sampling periods with an open path analyzer. Photosynthesis, stomatal conductance, and above ground biomass at 20 to 23 days were reduced in all four species by the larger variation in CO2 concentration. Tests of rates of stomatal opening and closing with step changes in light and CO2, and tests of responses to square-wave cycling of CO2 were also conducted on individual leaves of these and three other species, using a leaf gas exchange system. Reduced stomatal conductance due to larger amplitude cycling of CO2 during growth occurred even in soybeans and rice, which had equal rates of opening and closing in response to step changes in CO2. The gas exchange results further indicated that reduced mean stomatal conductance was not the only cause of reduced photosynthesis in variable CO2 conditions.


Sign in / Sign up

Export Citation Format

Share Document