Fruit quality of sweet pepper as affected by foliar Ca applications to mitigate the supply of saline water under a climate change scenario

BACKGROUND Sweet pepper fruit quality disorders have been related mainly to an unbalanced nutrient supply and non‐optimal growth conditions. Increases in the atmospheric CO2 concentration ([CO2]) have been associated with a reduction of transpiration, which can affect calcium (Ca) uptake as it is linked closely to water uptake. We investigated whether foliar application of Ca can counterbalance the effects of saline water and elevated [CO2]. RESULTS High CO2 favoured generative growth instead of vegetative growth. Foliar Ca supply did not affect the marketable yield, but reduced the total yield when combined with salinity and 400 µmol mol−1 CO2. Salinity affected negatively the total yield but this was overcome when CO2 was applied. The B and K concentrations were reduced by foliar Ca application, while Ca and Mn were increased at 400 µmol mol−1 CO2. Salinity increased the Mn, Cl, and Na concentrations, regardless of the [CO2], and decreased K at 800 µmol mol−1 CO2. The total protein was affected negatively only by elevated [CO2], and the total free amino acid concentration was reduced by all treatments. CONCLUSION The effect of Ca application differed according to the other treatments applied. This procedure should be optimised to overcome future climate impacts on fruit quality. © 2017 Society of Chemical Industry