Sphagnum moss is a promising growth substrate in arctic bramble container cultivation

ABSTRACT Development of container cultivation methods for arctic bramble (Rubus arcticus L.) is currently underway. The aim of this study was to evaluate Sphagnum moss and two substrate mixes containing peat and coir or perlite as alternatives for a pure peat substrate in arctic bramble container cultivation, with particular interest on Sphagnum moss. The experiment was conducted in plastic high tunnel in plant towers with three planting levels (Top, Middle, Bottom). The substrates used were unfertilised peat (UP), an UP and perlite mix (80/20 by dry loose volume) (UPP), an UP and commercial coir mix (50/50) (UPCoir) and unfertilised Sphagnum moss (SM). Plant vigour was higher in SM compared to UP and UPP, while total fruit yield, mean fruit weight and individual drupelet weight were higher in SM compared to UPP. Both plant vigour and fruit yield were substantially reduced on Middle and especially Bottom level, compared to the Top level of plant towers. Water retention measurement of pure substrate materials showed higher air volume content in SM compared to UP or pure coir material. We conclude that Sphagnum moss is a highly promising substitute for peat as a substrate in arctic bramble container cultivation.