Prohexadione-Calcium Inhibits Runner Formation and Enhances Yield of Strawberry

Abstract

Prohexadione-calcium (ProCa) was evaluated for inhibition of runner formation and plant performance in a modified plasticulture system used for growing strawberries ( Fragaria× ananassaDuch.) in the Northeast using summer planted cold-stored plants. Rates between 62.5 to 189 mg•L ^-1in multiple applications were evaluated but the rates between 125 and 189 mg•L ^-1were most effective. ProCa reduced runner formation but initiation of treatments within 3 weeks of planting and 3 sprays applied at 3-week intervals appeared to be necessary for complete runner suppression. The inhibitory effects from an application of ProCa lasted for about 28 days. ProCa decreased petiole growth, runner weight and runner number, but increased root to shoot ratio, the number of branch crowns, the number of inflorescences, and total marketable yield without affecting mean fruit size. The number of fruit harvested early was reduced, peak fruit production was delayed and harvest extended later into the season. The performance of plants treated with ProCa was equal or superior to plants where runners were removed manually during the course of plant growth and development.