Ecophysiology of coconut palm under water stress

Abstract

Coconut palm is of great social and economic importance for millions of people in the tropics and subtropics. Drought is one of the main environmental factors that limit coconut productivity. In this review, physiological and morphological data are presented in an integrated perspective to provide a holistic view of the behavior of coconut trees facing water deficit under both field and controlled conditions. Great capacity to produce homorhizic roots capable of searching continuously for water and nutrients and high protoplasmic tolerance in leaves allows the coconut tree to endure water deficit. High membrane stability, osmoprotection, osmoregulation and enhanced activity of antioxidant enzymes are characteristics often found in leaves of drought-stressed coconut trees. Information on leaf gas exchange, leaf water potential, water-use efficiency and stomatal behavior was compiled highlighting the differences among cultivars and hybrids under water stress. Genotypic differences in physiological and morphological traits can largely explain the agronomic performance of field-grown coconut trees under drought conditions.