Chrysanthemum response to polyaspartic acid in peat-based media and mineral soil

This study evaluated the growth and flowering of hardy chrysanthemum (Dendranthema x morifolium) in peat-based media and mineral soil treated with Amisorb - a polyaspartic acid product. Growth and flowering response was evaluated in three experiments -two in peat-based media (Promix BX®) and one in mineral soil (Sassafras sandy loam). In the first, Amisorb was applied biweekly, beginning at planting at 0.03 and 0.06 mL/5-gal pot. Chrysanthemums were fertilized weekly with 300 mg L^-1 20-20-20. The second experiment compared biweekly Amisorb applications at 0.02 and 0.04 mL/2-gal pot. Plants were fertilized at each irrigation with 100 or 200 mg L^-1 20-20-20. No significant differences in dry weight or flowering resulted from Amisorb in either experiment. Flowering and dry weight were significantly greater for 200 mg L^-1 20-20-20 than for 100 mg L^-1 20-20-20 applied with each irrigation. In the mineral soil experiment Amisorb was applied weekly at a rate of 0.06 mL/5-gal pot with a fertilizer solution consisting of 300 ppm 15-15-15. Amisorb did not significantly increase chrysanthemum blossom number and dry weight per plant in mineral soil.