Growing Undercover
Florida Tunnel Production
By: Skeeter Bethea
Florida Production





Located nearly at sea level about 25 miles east of the Sarasota
Coast on the Gulf of Mexico is Enza Zaden’s Myakka City,
Florida Research Station. This location presents a favorable
climate for tunnel production, though not without it’s
challenges.
Florida’s mild winters bring an average low of 48F (Lowest
recorded 18F) and has an average of only 5 days per year with
below freezing temperatures.
Those temperatures are balanced by high annual
temperatures averaging 92F. The highest recorded
temperature reached a steamy 105F, and Florida sees
approximately 134 days per year at about 90F.
Florida is also one of the highest light environments on the
East coast.
Those warm temperatures are assets, but heavy rain and frost
threaten production.
Specs
Location
Tunnel Manufacture
Deminsion/House
# houses in range
Concept/Design
Container
Media
Row Spacing
Plant Spacing
Plant Population
Fertilizer
Injection
Dripper
Myakka City, FL
Tunnel Tech
150ft long x 28ft wide
5 houses
Passisve Ventilation**
3gal cheater pot
Fafard 51L (60% 3/8" pine bark, 30% candian peat, 10% perlite)
7 ft centers
Double row 14 inch spacing
10,667/ac, .24plnts/sqft, 2.64plnts/m2
A and B mixes
Proportional: Dosamatic
Netafim O1WPCJL8-b, 2.1 gph (1/pot)
The Tunnel Concept



We use gutter connected, 28’ wide by 150’ long tunnel spans
that are covered in a single layer of polyethylene with 88%
light transmission.
With the use of roll up doors, arched end cap vents, and the
use of Svensson’s OLS30 shade cloth over the trellis, we
successfully achieve a “Passive Ventilation” system that keeps
optimal temperature in the growing zone.
The porous ceiling of the shade cloth inside the tunnel creates
a barrier with the hottest air being concentrated in the attic
space and ventilated out through the arched end cap vents by
wind and buoyancy.
Gutters
Open View
Airflow
Airflow
Airflow
Tunnel
Growing
ZoneZone Outside Outside
Tunnel
Growing
TunnelTunnel
Attic Attic
Date
Air Temp
(oF)
Growing
Degree
Min Max Avg Days
()
Date
Air Temp
(oF)
Growing
Degree
Min Max Avg Days
()
Date
Air Temp
(oF)
Growing
Degree
Min Max Avg Days
()
04/01/2013 63.2 104.2 84.8
84
04/01/2013 62.3 89.7 76.7
76
04/01/2013 65.5 82.0 75.1
75
04/02/2013 58.2 113.4 79.1
79
04/02/2013 57.1 95.3 71.8
71
04/02/2013 59.0 84.2 70.5
70
04/03/2013 57.2 107.7 76.7
76
04/03/2013 56.5 89.5 70.6
70
04/03/2013 59.7 87.1 72.7
72
04/04/2013 63.2 84.7 68.4
68
04/04/2013 61.6 76.9 65.7
65
04/04/2013 65.5 71.2 68.6
68
04/05/2013 57.1 94.5 71.4
71
04/05/2013 56.6 81.2 66.6
66
04/05/2013 60.4 74.1 67.8
67
04/06/2013 55.4 106.6 74.7
74
04/06/2013 54.1 91.0 68.0
68
04/06/2013 57.6 78.4 66.8
66
04/07/2013 55.5 62.3 57.4
57
04/07/2013 54.8 59.9 56.4
56
04/07/2013 58.3 64.0 60.7
60
04/08/2013 61.9 110.6 89.7
89
04/08/2013 60.9 94.2 80.0
80
04/08/2013 65.5 84.9 78.0
78
04/09/2013 57.2 106.7 75.1
75
04/09/2013 56.5 91.6 69.7
69
04/09/2013 59.7 84.2 72.0
72
04/10/2013 58.6 113.2 79.5
79
04/10/2013 57.5 92.7 71.8
71
04/10/2013 61.9 88.5 73.2
73
04/11/2013 64.9 109.5 79.2
79
04/11/2013 63.6 92.7 73.4
73
04/11/2013 68.4 87.1 76.1
76
04/12/2013 68.8 93.1 78.8
78
04/12/2013 67.1 84.3 73.6
73
04/12/2013 72.7 82.8 77.4
77
04/13/2013 N/A N/A N/A
N/A
04/13/2013 N/A N/A N/A
N/A
04/13/2013 N/A N/A N/A
N/A
04/14/2013 N/A N/A N/A
N/A
04/14/2013 N/A N/A N/A
N/A
04/14/2013 N/A N/A N/A
N/A
04/15/2013 69.0 118.0 94.3
94
04/15/2013 68.0 99.1 83.6
83
04/15/2013 73.4 90.7 82.8
82
04/16/2013 64.9 120.1 84.0
84
04/16/2013 63.5 101.9 77.2
77
04/16/2013 68.4 90.0 78.1
78
04/17/2013 63.6 112.5 87.8
87
04/17/2013 62.3 95.5 79.2
79
04/17/2013 66.9 87.1 78.6
78
04/18/2013 62.4 107.0 82.4
82
04/18/2013 61.1 90.4 74.5
74
04/18/2013 65.5 88.5 77.3
77
Temperature Monitoring
Pollination
Harvest Goals
Planting
Date
Harvest
Window
Round
Tomato
Yield
Colored
Pepper
Cucumber*
9/15
12/1 – 5/1
20lbs/plnt
11lbs/plnt
15lbs/plnt
*Cucumbers are a 10 week harvest so you would need 3 plantings to span the same
Window as the tomatoes and pepper.
Pepper
Pepper
Tomatoes
Cucumber
Determinates
Contact Information

Cravo
Ben Martin
905-317-3546
benjaminM@cravo.com

Tunnel Tech
Kathleen Fouse
717-208-1693
1-855-TTTunnels
k.fouse@tunneltech.com
Thank You!



Thanks for the opportunity
Thanks to Enza Zaden
Any questions?
Skeeter Bethea
william.bethea@enzausa.com