FALL FRUITING RASPBERRY PRODUCTION UNDER PLASTIC TUNNELS

Abstract

From 1988 to 1990, the fall fruiting raspberries Heritage, Perron Red, Autumn Bliss and 3413-12 were field evaluated under two cultural systems: conventionnal production and production under plastic tunnel. The plastic tunnel was in place over 4 rows from early September to late October without supplemental heating. Compared to the conventionnal system, the tunnel contributed to a lengthening of 1 to 4 weeks in the fruiting period 2 years out of 3. In spite of the higher day temperatures, the rate of fruit ripening was not increased under the tunnel but fruit size was increased slightly. However, the latter did not translate in higher yield per day since fruit number decreased under the tunnel. Total yield increased only one year when the first killing frost occurred a full month before the second one. Generally, night temperatures were as low in the tunnel as those outside.