Studies of the dormant phase of the hop (Humulus lupulus L.)
Williams, I.H.; Roberts, J.B.; Coley-Smith, J.R.
Annual Report - Department of Hop Research. Wye College 1961: 48-58
Potted plants, from ah open standing-out ground, taken into a growth room (65 degrees F. and 9-hour photoperiod) in early January all began making vigourous shoot growth within 14 days, whereas plants that had been taken in earlier grew very little. Plants kept in a refrigerator at 38 degrees F. for 6 weeks after the onset of dormancy grew vigorously when transferred to the growth room. During the breaking of dormancy starch was gradually transformed into soluble sugars.