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Salinity stress is a limiting factor that affects attainment of optimal yield of many vegetable crops at various growth stages in many arid and semi-arid parts of sub-Saharan Africa. The objective of this study was to explore salt tolerance of tomato (Solanum lycopersicum L.) genotypes under the influence of gibberellic acid (GA3) and Bacillus subtilis under screen house conditions. Tomato seeds were pre-soaked with 0, 0.4, 0.5 or 0.6 mM concentrations of GA3 and control in distilled water, respectively; for 12 hr at room temperature. The seeds were germinated in a screen house in 10 kg of soil contained 0, 100, or 200 mM NaCl treatment in polyethene bags. After two weeks of seed germination, the seedlings were inoculated with B. subtilis with the exception of controls. Results revealed that the single or combined treatments of GA3 (at different concentrations) and Bacillus subtilis significantly (P<0.05) increased photosynthetic pigments, and enhanced the concentrations of potassium, calcium, magnesium and phosphorus ions in the salt-stressed tomato. Both tomato genotypes showed low concentrations of sodium ions at all levels of gibberellic acid with Bacillus subtilis. Also, there were significant (P < 0.05) increases in the compatible solutes, antioxidant enzymes activity and antioxidant potential of salt-stressed tomato genotypes, in the combined treatments of GA3 and Bacillus subtilis. Tomato genotypes treated with GA3 and Bacillus subtilis, showed greater salt-tolerance even at high levels of salinity, than single treatment of either GA3 or Bacillus subtilis. Based on these findings, the genotypes are suitable for future breeding programmes to achieve optimal crop yield in saline conditions.

Salinity stress causes a major threat to crops productivity across the globe. The effects of salt stress on photosynthetic pigments and minerals content were studied in this research work. The seeds of the two genotypes of okra (47-4 and LD 88) were pre-soaked in the solutions of IAA (0.4, 0.5, and 0.6 mM concentrations) and the seeds were sown in 10 kg of soil in polyethene bags already contained 0, 100, and 200 mM NaCl respectively. Salinity stress significantly reduced photosynthetic pigments and minerals content of the two genotypes of okra. Treatment of okra seeds with IAA at varying concentrations improved salt tolerance of the two genotypes, which is evident with increase photosynthetic pigments and minerals concentrations under salinity stress relatives to the negative control groups. Finally, we can infer from the results of this study that pre-soaked seeds with 0.4 mM IAA significantly ameliorated the effects of salinity on the two genotypes of okra, and this concentration could serve as a promising phytohormone for okra plant under moderate and severe salt levels.