Effects of oxygen fertilization on damage reduction in flooded snap bean (Phaseolus vulgaris L.)

Flooding is one of the major abiotic stresses for vegetable production in Florida. Hydroponic and pot trials were conducted with snap bean to evaluate the effects of oxygen fertilization on the biochemical and physiological status of flooded snap bean plants. There were three treatments in the hydroponic trials were: (1) flooded (control), (2) bubble aeration with ambient air, and (3) hydrogen peroxide (H₂O₂) applied at the beginning of the trial. Plant health was evaluated by determining nitrogen (N) and phosphorus (P) uptake rates. The greenhouse pot trials were used to quantify the effects of three different application rates of solid oxygen fertilizers as calcium peroxide (CaO₂) and magnesium peroxide (MgO₂). The results showed that plant N and P uptake rates were significantly greater (p < 0.05) with H₂O₂ than without H₂O₂. The N uptake rates with H₂O₂ were like that of those with bubbling. The uptake rate of NH₄⁺ was significantly greater than that of NO₃^- with the bubbling and H₂O₂ conditions_, but the uptake rate of NO₃^- was significantly greater than that of NH₄⁺ in the flooding condition. The plant height, leaf greenness, shoot biomass, and yield were all significantly greater with CaO₂ or MgO₂ than without either solid oxygen fertilizer. The minimum damage of flooded snap bean was found with 2 g CaO₂ or 4 g MgO₂ per pot. These results indicated that oxygen fertilization may potentially improve yield of flooded snap bean plants.