Physico-chemical characteristics and productivity of tomato plants in function of nitrogen sources and doses

Abstract

The objective of this study was to evaluate the effect of nitrogen sources and rates on the physicochemical characteristics and yield of tomato plants. Forty hybrids were cultivated at 100 and 400 kg ha^-1 of N, combined with four sources (urea, ammonium sulfate, ammonium nitrate and calcium), plus a treatment without N application in a randomized complete block design four replicates. Size, stem diameter, number of leaves, SPAD (Soil Plant Analysis Development), leaf nitrogen, number of fruits / plants, fruit firmness, bark thickness and average fruit size, ° BRIX, pH, calcium, potassium and sodium in fruits. There was an increase in SPAD index, Brix and longitudinal diameter of fruits as a function of the N dose. The use of ammonium nitrate and calcium provided stronger fruits. Urea and ammonium nitrate provided the highest pH value in tomato fruits. The application of the 100 kg ha-1 dose of N resulted in the highest potassium content in fruits. The highest productivity was obtained with the application of sources containing ammonium and the lowest in the control treatment. Sources and doses of nitrogen fertilizers influenced growth, productivity and parameters related to tomato quality.