Field experiments were conducted in Gainesville, Florida, to determine the response of 'White Stem' C h i n e s e cabbage to foliar applications of the biostimulant folcysteine. Rates of 100, 300, 500 and 700 ppm folcysteine were applied once (7 days after transplanting) or twice (7 and 21 days after, transplanting). Plant fresh biomass was determined 50 days after transplanting. Results show that 'White Stem' pok-choi was responsive to folcysteine. When the biostimulant was applied once, overall growth was enhanced as rates increased, reaching maximum yield at the rate of 500 ppm as determined by a quadratic relationship (y = 21.8 + 0.20x - 0.0002x2; r2 = 0.97). Yield decreased at the rate of 700 ppm. When folcysteine was applied twice, the highest yield was obtained at 100 ppm per spray, with higher rates failing to increase yields above control levels. A linearplateau equation characterized this relationship (y = 23.8 + 0.27x, if χ < 100; y = 23.8, if χ > 100)