The objective of this work was to optimize a soilless growing system for producing bare-root
strawberry transplants in three organic substrates. Three trials were conducted in the Quebec
City area to determine the productivity potential of a peat-sawdust mixture (PS25) and
an aged bark (AB) material compared to conventional coconut fiber (CF) substrate. A first
experiment was carried out to define appropriate irrigation set points for each substrate that
allowed optimal plant growth and fruit yields. For all substrates, wetter conditions (irrigation
started at -1.0 kPa for CF; -1.5 kPa for AB and PS25, relative to -1.5 kPa for CF; -2.5 kPa for
AB and PS25) enhanced plant growth and fruit production. The second trial was carried out
to test the productivity potential for commercial production of the three substrates using
high-tunnels. After the addition of an initial fertilizer application to PS25, we successfully
established bare-root plants that gave similar fruit yields than those in CF and AB. The productivity
potential of PS25 and AB were further confirmed during a third trial under greenhouse
conditions. The critical factor for plant establishment in PS25 was attributed to
consistent N, P and S immobilization by microorganisms, as well as the retention of other
elements (Mg2+, K+) in the growth media. Taken together, our results showed that PS25
and AB are promising alternative substrates to coconut coir dust for strawberry cultivation.
This paper also provides a useful guide for strawberry cultivation in Quebec, and suggests
future research that might be conducted to optimize soilless systems for cold-climate strawberry
production in Northern America.