Fertigated cultivation of mini watermelon subjected to salinity levels and foliar application of silicon

Abstract

ABSTRACT The application of silicon (Si) represents one of the alternatives that can be used to mitigate the deleterious effects caused by salinity on plants in fertigated cultivation. The objective was to evaluate the effect of different levels of water salinity, associated with the use of sodium silicate on the production parameters and nutrient levels in the leaf and stem of mini watermelon in a protected environment. To conduct the experiment, a randomized block design was adopted, in a 6 x 2 factorial scheme, with 4 repetitions, with six levels of irrigation water salinity (1.05; 2.12; 3.26; 4.41; 5.91 and 7.32 dS m-1) and two types of Si application: without Si and in foliar solution. The following parameters were evaluated: plant height, stem diameter, number of leaves, leaf and stem fresh and dry mass; biometric variables and total soluble solids content in the fruits; and nutrient contents in leaves and stem. The use of Si associated with fertigation with different salinity levels promoted a positive response for peel thickness, ºBrix, fresh and dry mass of leaves, and Si accumulation in leaves and stem. Salinity alone promoted an increase in pulp weight, ºBrix of the fruits and potassium content in the stem, besides increasing the manganese content and inhibiting the zinc content in the leaves. There was a significant interaction for the manganese content in the stem, with a positive response in the absence of foliar-applied Si and a negative response in the presence of foliar-applied Si under different levels of salinity.