Influencia de la aireación de la solución nutritiva y de la fecha de cosecha en la producción y calidad de lechuga baby leaf

Résumé

The aim of this work was to assess the influence of different levels of aeration of the nutrient solution on the growth and quality of a baby leaf lettuce crop. The green batavia ‘Ganeria’ was grown in a floating system in a autumn cycle. Three levels of aeration of the nutrient solution (high, low and no aeration) were tested. Two harvests were carried out; the first at 22 days after sowing (DAS) and the second after 27 DAS. The aerial part growth, nitrate and total phenols contents, antioxidant capacity and hue angle were measured in lettuce leaves at the harvesting day in both harvests. The differences among the levels of dissolved oxygen in nutrient solution were maintained between the two harvests. Regarding to aerial part growth, only significant differences between plant heights were found among aeration levels in both harvests. Nitrate and total phenols contents and antioxidant capacity were increased at the second harvest, but the hue angle value was maintained. Aeration significantly increased nitrate content and decreased total phenols content and antioxidant capacity at the first harvests. At second harvest only antioxidant capacity was affected, where the lowest value was found at the highest level of aeration. In conclusion, under conditions in which no aeration was provided, there was a slight decrease in plant growth, but the final quality of the product was improved because the content of functional phytochemicals were increased and nitrate content was decreased.