PHYSIOLOGICAL RESPONSES OF DWARF COCONUT PLANTS UNDER WATER DEFICIT IN SALT-AFFECTED SOILS

Authors

  • Alexandre Reuber Almeida da Silva Department of Education, Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Iguatu, CE
  • Francisco Marcus Lima Bezerra Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
  • Claudivan Feitosa de Lacerda Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
  • Carlos Henrique Carvalho de Sousa Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
  • Malos Alves Bezerra National Center for Tropical Agroindustry Research, Empresa Brasileira de Pesquisa Agropecuária, Fortaleza, CE

DOI:

https://doi.org/10.1590/1983-21252017v30n220rc

Keywords:

Cocos nucifera L.. Water and salt stress. Physiology.

Abstract

The objective of this study was to characterize the physiological acclimation responses of young plants of the dwarf coconut cultivar ‘Jiqui Green’ associated with tolerance to conditions of multiple abiotic stresses (drought and soil salinity), acting either independently or in combination. The study was conducted under controlled conditions and evaluated the following parameters: leaf gas exchange, quantum yield of chlorophyll a fluorescence, and relative contents of total chlorophyll (SPAD index). The experiment was conducted under a randomized block experimental design, in a split plot arrangement. In the plots, plants were exposed to different levels of water stress, by imposing potential crop evapotranspiration replacement levels equivalent to 100%, 80%, 60%, 40%, and 20%, whereas in subplots, plants were exposed to different levels of soil salinity (1.72, 6.25, 25.80, and 40.70 dS m-1). Physiological mechanisms were effectively limited when water deficit and salinity acted separately and/or together. Compared with soil salinity, water stress was more effective in reducing the measured physiological parameters. The magnitudes of the responses of plants to water supply and salinity depended on the intensity of stress and evaluation period. The physiological acclimation responses of plants were mainly related to stomatal regulation. The coconut tree has a number of physiological adjustment mechanisms that give the species partial tolerance to drought stress and/or salt, thereby enabling it to revegetate salinated areas, provided that its water requirements are at least partially met.

Author Biographies

  • Alexandre Reuber Almeida da Silva, Department of Education, Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Iguatu, CE
    Engenheiro Agrônomo, Mestre e Doutor em Engenharia Agrícola, Área do Conhecimento: Engenharia de Água e Solo; Professor do Instituto Federal do Piauí.
  • Francisco Marcus Lima Bezerra, Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
    Engenheiro Agrônomo, Mestre e Doutor em Irrigação, Área do Conhecimento: Engenharia de Água e Solo; Professor da Universidade Federal do Ceará.
  • Claudivan Feitosa de Lacerda, Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
    Engenheiro Agrônomo, Mestre em Solos e Nutrição de Plantas; Doutor em Fisiologia Vegetal, Área do Conhecimento: Engenharia de Água e Solo; Professor da Universidade Federal do Ceará.
  • Carlos Henrique Carvalho de Sousa, Department of Agricultural Engineering, Universidade Federal do Ceará, Fortaleza, CE
    Tecnólogo em Irrigação e Drenagem; Mestre e Doutor em Engenharia Agrícola; Área do Conhecimento: Engenharia de Água e Solo; Bolsista de PNPD da Universidade Federal do Ceará.
  • Malos Alves Bezerra, National Center for Tropical Agroindustry Research, Empresa Brasileira de Pesquisa Agropecuária, Fortaleza, CE
    Engenheiro Agrônomo, Mestre e Doutor em Fisiologia Vegetal, Área do Conhecimento: Engenharia de Água e Solo; Pesquisador da EMBRAPA Agroindústria Tropical; Professor da Universidade Federal do Ceará.

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Published

24-01-2017

Issue

Section

Agricultural Engineering