Postharvest quality of tomato as affected by nitrogen and sulfur interaction

Abstract

Nitrogen (N) and sulfur (S) are nutrients that, in addition to influencing plant growth and production, interfere with processes related to postharvest fruit quality. In the present study, N x S interaction was evaluated in the postharvest quality of tomato (Solanum lycopersicum L.). The experiment was conducted in a greenhouse using 5 dm3 capacity vessels containing a 0-20 cm layer of a dystropherric Red Latosol. A 5 x 3 factorial design was used, with combinations of five doses of N (0, 100, 200, 300 and 400 mg dm-3) and three doses of S (0, 60 and 120 mg dm-3) distributed in a completely randomized design, with four repetitions. After harvest, the attributes of fruit quality were evaluated: firmness, pH, soluble solids (SS), titratable acidity (AT), soluble solids ratio and titratable acidity (SS / AT), vitamin C, lycopene and beta-carotene. An increase in firmness was observed, as well as the content of soluble solids, titratable acidity and the SS / AT ratio of the fruits as a result of the interaction N x S. However, this interaction favoured the reduction of the contents of vitamin C, lycopene and beta-carotene, and the quality characteristics of tomato fruit in relation to the recommended values. Only the increasing doses of N favoured a higher pH in the tomato fruits.