Effect of temperature, photoperiod and pretreatment growing condition on floral induction in springbearing strawberry

Abstract

‘Chandler’ strawberry plants (Fragaria × ananassa Duch.) were greenhouse grown under natural lighting and then placed into growth chambers at two constant temperatures of 16°C and 26°C and two day lengths of 9 h (SD) and 9 h photoperiod (NI) which was night interrupted with 3 h of incandescent radiation at 30-45 µmol s-1m-2 PAR. Plants were given different numbers of inductive cycles in growth chambers and then moved to the greenhouse where flowering and growth were monitored. Flowering was completely inhibited at 26°C, regardless of pretreatment growing conditions such as pot sizes and plant ages, photoperiod and inductive cycles. At 16°C, SD promoted floral induction compared to NI under all inductive cycles except a 7-day induction. The minimum number of inductive cycles required at 16°C for floral induction was dependent on photoperiod and prior greenhouse treatment. Flowering rate was also affected by greenhouse treatment, photoperiod and inductive cycles. Runner production was affected by photoperiod and temperature × inductive cycle. © 2000 by The Haworth Press, Inc. All rights reserved.