Root production can be stimulated reliably by storing unrooted runners at 5 degsC for some days but this requires access to refrigerated storage space. In the experiments reported here, cuttings were taken from runner tips and cotton cloth was wrapped around the crown tissue.
Solutions of various growth regulators were applied by dripping them onto the cloth at the appropriate concentration when dissolved in a solution containing 10 per cent Tween 20 (a wetting agent).
Treated cuttings were placed at 30 degsC on a mesh at the bottom of a box containing some water, which allowed a high humidity to be maintained. After two days, the cloths were removed.
Control cuttings were maintained for two days in a 16-hour day at 5 degsC but without cotton cloths. The cuttings were then cultured for five more days, after which rooting was assessed.
Treatment with either 20ppm or 100ppm abscisic acid (ABA) at 30 degsC was far more effective than treatment with any other growth regulator at this temperature and both were as effective as storage at 5 degsC for two days.
Stimulation of Rooting from Cuttings of Strawberry Runner Plants by Abscisic Acid Under High Temperature Condition by Saito, Bantog, Morimoto, Horibe, Yamada and Yamaki (2009). Journal of the Japanese Society for Horticultural Science 78 (3): 314-319. Available online at www.jstage.jst.go.jp/browse/jjshs1.