Abstract
With the development of nutrient best management practices (BMPs) for vegetable crops N fertilizer recommendations must be high enough to ensure maximum economic tomato (Lycopersicon esculentum Mill.) yield without detrimentally affecting water quality. The current statewide UFIFAS N rate recommended rate of 200 lbs/acre (with supplemental fertilizer applications under specified conditions) may need adjustment based on growing season, soil type, and irrigation system type. The objectives of this project were to establish partnerships with southwest Florida tomato growers and to evaluate N fertilizer rate effects on yield. In 2005-2006, eight on-farm trials were conducted in the fall, winter and spring with N rates ranging from 200 to 330 lbs/acre. Total tomato yields did not differ between N treatments except in one seepage/winter trial. Applying more than 200 lbs/acre N produced higher yields of large and medium fruits at third harvest during winter and spring. A high level of grower engagement created a popular BMP program. Tomato yield can fluctuate widely by season and year due to weather conditions. Farm level prices are also volatile, responding to supply fluctuations in Florida and competing production areas. Nitrogen fertilizer is a minimal production system cost, so growers treat it as inexpensive insurance. To change the grower paradigm, BMP N rate research must be conducted during all seasons, at as many locations, and for as many years as possible in order to identify response trends.
