INTERACTIVE EFFECTS OF SALINITY AND PHOSPHORUS-NUTRITION ON TEPARY AND COMMON BEAN CULTIVARS

Increasing plant phosphorus (P) supply has been shown to either increase or decrease the salt tolerance Of many crops. A hydroponic culture experiment was conducted in the greenhouse using aerated Hoagland nutrient solution to examine interactive effects of salinity (10, 50, and 100 mM of NaCl) and P (1, 10, and 100 muM of H3PO4) on shoot and root growth, and foliar injury on two common bean (Phaseolus vulgaris) and two tepary bean (Phaseolus acutifolius) genotypes. Increased P enhanced the tolerance of common bean plants to NaCl, significantly increasing shoot and root growth, and reducing foliar injuries. However, this relationship was not found in tepary bean plants at highly salinized full-strength Hoagland nutrient solution levels. These results indicate that adequate P nutrition appears to be involved in the enhancement of salt tolerance of common bean plants.