Sequential Transplanting of Parthenocarpic Cucumbers in Organically Managed High Tunnels in Hardiness Zone #7 & #8 of North Carolina

Fresh market cucumber is a highly profitable crop in high tunnels. However, information on its production in hardiness zone 7&8 of North Carolina was very limited. The objective of this project was to determine the best time for planting parthenocarpic (seedless) cucumbers in high tunnels in spring and fall, and to explore the economic potential of the crop in organic managed high tunnels. Seedless cucumber ‘Tyria’ and ‘Socrates’ were tested in high tunnels (30’x96’x5’) located in Greensboro (zone7) and Goldsboro (zone 8) for spring and fall of 2014 and 2015. Treatments include three sequential transplanting dates that were 10 days apart starting from 31 March and 27 August 2014 or 2 April and 11 August 2015. Two rows of seedlings were transplanted in each of 30”-wide, black plastic mulched raised bed, with a row spacing of 12” and in-row spacing of 18”. Beds were irrigated with one drip tape (5/8”, 8 mil, 12” emitter spacing) that was buried in the middle of beds under the plastic mulch. The high tunnels were covered with single (Greensboro) or double-layer (Goldsboro) 6-mil polyethylene films. Temperatures inside the high tunnel were managed between 50-85°F (optimal 68-85°F) through opening/closing sidewalls and applying row covers, when temperatures inside the high tunnel went below 50°F. The experiment was conducted as a split-plot design with four replications, cultivars being main plots and planting dates as split plots. A total of 8 seedlings were planted in each split plot. Results indicated that planting dates around 10 April for spring production or early August for fall production would work best for both zones. For a single-bay high tunnel with two beds (four rows) of cucumber, the estimated gross income was about $6,000 which translates to $18,000 per high tunnel. The estimated net income was $15,122 or $4.04/ft²/season excluding infrastructure. Our research proved that seedless cucumber could be a profitable crop for organic high tunnels in plant hardiness zones 7&8.