Flowering Response of ‘Heritage’ Red Raspberry to Temperature and Nitrogen1

Abstract

Plants of the fall-bearing red raspberry ( Rubus ideaus L. cv. Heritage) were grown in 2 day/night temperature regimes (29/24°C and 25.5°/20°) under a 16-hour day with 3 nitrogen levels (0, 5 or 10 mg N/week). Canes flowered 2 weeks earlier and more profusely in the higher temperature. Nitrogen promoted greater cane growth, more flowering nodes per cane, and increased flowering per unit vegetative growth. The combination of high temperature and high nitrogen promoted greatest cane elongation, earliest and most profuse flowering, and the most flowers per unit of cane growth.