Optimizing Phosphorus Rate for the Sustainability of Commercial Snap Bean Production in South Florida

Adequate phosphorus (P) application rates are critical for enhancing the profitability of a shallow rooted vegetable crop like snap bean (Phaseolus vulgarisL.). The goal of this study was to optimize P application rate for commercial snap bean production in south Florida. This study was conducted on muck soil in Lake Harbor in winter 2011 and on fine sandy soil in Belle Glade in spring 2012. Prior to planting ‘Caprice’ snap bean, plots were fertilized with 0, 40, 80, 120, 160, 200, and 240 lb/acre P2O5(0, 45, 90, 134, 179, 224, and 269 kg·ha–1P2O5) using triple superphosphate (0–45–0). Each plot consisted of eight 30-ft rows (4 replicates each), of which the central 20 ft of the two middle rows was harvested. In both of the trials, an increase in P2O5application rates produced significant increases in marketable bean yields up to the 120 lb/acre P2O5, at which point significant gains measured from further increasing application rates ceased. At 120 lb/acre P2O5, measured bean quality was the best among all of the treatments. These results indicate 120 lb/acre P2O5as the optimum P rate for the sustainability of commercial snap bean production in these areas in south Florida.