Gas exchange and chlorophyll fluorescence in spearmint (Mentha spicata L.) leaves influenced by mineral nutrition Dahkki Cano-Gallego, Lucas Esteban, Minchalá-Buestan, Nube, Loaiza-Ruíz, Ruby Alejandra, Cartagena-Valenzuela, José Régulo, Córdoba-Gaona, Oscar de Jesús