Effects of Phosphorus on Morphology of Hydroponically Grown Scaevola aemula R. Br. "Whirlwind Blue"

Authors: BURNETT, STEPHANIE - UNIVERSITY OF MAINE; ZHANG, DONGLIN - UNIVERSITY OF MAINE; STACK, LOIS - UNIVERSITY OF MAINE; He, Zhongqi

Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2007
Publication Date: 7/16/2007
Citation: Burnett, S.E., Zhang, D., Stack, L.B., He, Z. 2007. Effects of Phosphorus on Morphology of Hydroponically Grown Scaevola aemula R. Br. "Whirlwind Blue". American Society of Horticulture Science Meeting. HortScience, Vol 42 page 874

Interpretive Summary:

Technical Abstract: The popular hanging basket plant, fan-flower (Scaevola aemula R. Br. ‘Whirlwind Blue’), is cultivated from low phosphorus soils and requires minimal supplemental phosphorus. To accurately evaluate the effects of phosphorus on morphology, fan-flower was grown hydroponically in order to maintain concentrations of all nutrients except phosphorus at equal levels. The nutrients were supplied in half-strength Hoagland solutions containing 0, 20, 40, 60, or 80 mg/L of phosphorus and 134 mg/L of nitrogen. Plants grown with 0, 60, or 80 mg/L had significantly fewer flower branches and total flowers when considered marketable, than those grown at 20-40 mg/L. Plants grown with 20-60 mg/L of phosphorus had the longest branches; however, plants grown with 0 mg/L of phosphorus had roots 40-54% longer than those grown at all other concentrations. Little new root growth was observed in fan-flower grown at the highest phosphorus concentration. Furthermore, foliage from these plants was chlorotic to nearly white. Results indicate that phosphorus concentrations higher than 40 mg/L reduced growth, flower number, and thus quality of fan-flower. Growers should avoid applying fertilizers with high phosphorus concentrations to these plants.