Vol. 121 (2008): Proceedings of the Florida State Horticultural Society
Vegetable

Evaluation of nitrogen rates and irrigation programs for tomato production in west central Florida

Bielinski M. Santos
UF/IFAS

Published 2008-12-01

Abstract

Two field studies were conducted to compare N rates by irrigation programs and their effects on tomato (Solanum lycopersicum L.) growth and yields. Twelve treatments resulted from combinations of irrigation and N fertilization programs. Irrigation programs were seepage irrigation at a water volume of 14 acre-inch/acre/season; seepage plus drip irrigation at a volume of 14 and 14 acre-inch/acre/season, respectively; and drip irrigation at a volume of 14 acre-inch/acre/season. N fertilization programs consisted of variations of preplant and drip-applied N at rates of 200, 250, and 300 lb/acre. Within the irrigation programs, the highest NO3-N petiole concentration was found in plots treated with a drip irrigation rate of 14 acre-inch/acre/season (448 ppm). For N rates, NO3-N petiole concentrations increased linearly with N rates and the highest values occurred with 300 lb/acre of N (435 ppm). Tomato marketable yield was the lowest (12.0 ton/acre) with the combination of seepage irrigation (14 acre-inch/acre/season) and with the preplant application of 200 lb/acre of N. All other irrigation by N fertilization combinations resulted on total marketable yields ranging between 19.4 and 25.9 ton/acre. These results indicated that in those systems where drip irrigation was used alone or in combination with seepage irrigation, a N rate of 200 lb/acre (bed centers 6 ft apart) might suffice for tomato production. In contrast, when only seepage irrigation was utilized at a rate of 14 acre-inch/acre/season, this N rate needs to be increased to 250 lb/acre.