The effect of two day-night temperature regimes and nutrient solution concentrations on growth on Lavandula angustifolia 'Munstead' and Magnolia soulangiana

Young plants of Magnolia soulangiana and Lavandula angustifolia 'Munstead' were given two concentrations of nutrient solution (EC = 0.8 or 1.6 mS cm(-1)) under negative or positive DIF regimes. Magnolia exposed to warm nights and cool days grew slower than under positive DIF treatment but root growth was not influenced. The plant's architecture was not altered significantly except for shorter internodes number 2, 3, 4 and 5 on the main shoot under negative DIF treatment. Negative DIF resulted also in reduced length of internodes and enhanced flowering of Lavandula without an adverse effect on plant growth. Only the dry matter content of the shoots was reduced. Use of nutrient solution with EC = 1.6 mS cm(-1) resulted in decreased height of Magnolia and drastically reduced growth but stimulated flowering of Lavandula comparing to nutrient solution of EC = 0.8 mS cm(-1). (C) 2000 Elsevier Science B.V. All rights reserved.