Determining the Ideal Transplanting Dates for Organic Tomato Production in High Tunnels in North Carolina

Tomato is one of the most important and profitable vegetable crops in high tunnel production. Information on planting dates of tomatoes in the Midwest has been well documented. Similar information in zone 7&8 of North Carolina, however, was very limited. The objective of this project was to determine the best transplanting time for tomato production in high tunnels for both spring and fall, and to explore the economic potential of growing tomato in organic high tunnels. Indeterminate tomato ‘Rabelski’ and ‘Big Beef’ were chosen for spring production while determinate tomato ‘Oregon Spring’ and ‘Defiant PHR’ were used for fall production. The trials were conducted in high tunnels (30’x96’x5’) located in Greensboro (zone7) and Goldsboro (zone 8) in 2014 and 2015. Treatments include three sequential transplanting dates that were 10 days apart starting on 10 April 2014 and 7 April 2015 or 5 September 2014 and 11 August 2015. Transplants were raised in a greenhouse. Two rows of transplants were planted (staggered) in each of the two 30”-wide, black plastic mulched raised bed, with a row spacing of 12” and in-row spacing of 18”. The high tunnels were covered with single- (Greensboro) or double-layer (Goldsboro) 6-mil polyethylene films. The experiment was conducted as a split-plot design with four replications and 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 in mid-April or early August worked best for spring or fall production, respectively. Transplanting in Early September has resulted no yield in fall 2014. It was suggested that tomato be a high profitable crop in high tunnels, as two beds (four rows) of organic tomato in a 30’x96’ high tunnel would result in $7,308 gross income which translates into a net income of $19,047 per high tunnel if the high tunnel cost itself is excluded.