Physiological responses of crops to sea water: Minimizing constraints that limit yield

Abstract

Growing plants under high salinity conditions using sea water or dilutions thereof impose many restrictions on growth and development. These restrictions translate into low productivity and economical viability in the agricultural system. Since most crop species are glycophytes, they are primarily suited to nonsaline conditions and the physiological adjustments and morphological changes that are possible, are severely limited. The use of highly saline water to grow crops requires an adequate drainage system and availability of adequate quantities of water. The abilities of particular plant genotypes to grow and produce yield under high salinity, well-drained environments is dependent upon restriction of salt from cytoplasmic compartments and maintenance of positive water balance. Temperature, humidity and light intensity have profound interactive effects with salinity at the upper limits of ionic and osmotic stress. Major research efforts are needed to: (1) Devise and test management strategies suited to different climatic environments for the cultivation of crops under high salinity. (2) Develop comprehensive plant models that integrate and interpret many of the known physiological and morphological responses to salt stress. (3) Initiate long-range breeding programs to select high salt tolerance in conventional crops and agronomic suitability in salt-tolerant wild species. (4) And, begin aggressive research in the area of molecular biology to identify and transfer genes and gene systems that confer salt tolerance in halophytes to glycophytic crop species.