Prohexadione-calcium applications to suppress runner growth in strawberries grown in a plasticulture system.

摘要

The labor and cost of runner (stolon) removal has slowed the adoption of plasticulture systems for strawberries in northern regions of North America. To provide adequate growing time, planting must occur earlier in the north than in the fall-planted southern region and, as a result, stolons (runners) are produced due to the warm, long-day conditions of summer. Runners are undesirable in plasticulture systems because they interfere with spraying and harvest, reduce marketable yield and are expensive to remove by hand. Prohexadione-calcium (Apogee?) is a gibberellic acid synthesis inhibitor that can reduce shoot growth in plants. Summer-planted ‘Honeoye’ strawberries grown in a plasticulture system in Maine, were treated with foliar sprays of prohexadione-calcium one, two or three times, approximately two weeks apart, at rates of 50 ppm, 100 ppm or 200 ppm, beginning when runner development was first noticed, or had runners removed by hand. The higher rates and doses of prohexadione-calcium in this trial provided the greatest inhibition of runner development and the highest marketable yield. Increasing rates and doses also tended to increase leaf number, reduce petiole and runner internode length, and reduce plant dry weights. Fruit size tended to be reduced under the highest number of sprays. Foliar sprays of prohexadione-calcium at 100-200 ppm appears to provide an effective means to reduce runner plant production for summer-planted strawberries grown in plasticulture.