Effects of Seed Piece Size and Cost on Yield and Economics of "Green" Ginger Production in Temperate-climate High Tunnels

Immature ("green") ginger can be grown successfully in high tunnels in temperate climates. Seed pieces (rhizomes), sourced from tropical production areas, are typically larger than required to produce a successful crop. We examined the effect of growing ginger in Minnesota using 4 sizes of seed pieces (30, 60, 90, or 120 g) created from dividing larger pieces before transplant. Plants were grown in Rosemount, MN, in 2013 and in Waseca, MN, in 2014, using raised beds in high tunnels. Equal numbers of seed pieces (23) were planted in each 1.8-m plot in four replicates each year. Rhizome yield was 1.9 kg·m^-2 in 2013 and 1.2 in 2014. Average yield was 0.9 kg·m^-2 using 30-g seed pieces (3.8-fold increase per kg planted), and 2.3 kg using 120-g seed pieces (2.4-fold increase per kg planted). Assuming relative seed costs of $8.80 or $2/kg, and production and labor costs of $13.99/m² regardless of seed costs, the break-even market price for green ginger ranged from $18.42 to $22.14/kg, respectively,  if 30-g seed pieces were used, and $10.02 to $15.78/kg, respectively, if 120-g seed pieces were used.  Net profit was less than $0 at a retail price of $11 per kg for green ginger unless 120-g seed pieces were used and seed costs were $8.80/kg. Returns at these prices ($2.23/m²) were less than estimates for high tunnel-grown cucumbers ($4.09/m²). At a retail price of $33/kg¹ for green ginger, net profit ranged from $9.15/m (30 g per seed piece, $22 per kg seed) to $53.79/m² (120 g per seed piece, $8.80 per kg seed). This is comparable to estimated profit of >$30/m² for tomatoes.

·