Basics of High Tunnel Production - 2017...Basics of High Tunnel Production - 2017 Terrance T. Nennich Extension Professor Emeritus Vegetable and Small Fruit Production University of

Basics of High Tunnel Production - 2017

Terrance T. Nennich Extension Professor Emeritus

Vegetable and Small Fruit Production University of Minnesota Extension

[email protected]

© 2012 Regents of the University of Minnesota. All rights reserved.

High Tunnel Research Sites in Minnesota

Experiment Stations Grower Cooperators


What are High Tunnels

• High tunnels are not a poor persons greenhouse

• High tunnels are a separate intense technology which allows crops to be grown up to three zones earlier and later and eliminate considerable risk.


What are High Tunnels?

• Structures that resemble some greenhouses - in appearances only

• Use no artificial heat (except for emergencies)

• Use no artificial ventilation such as fans, tubes or forced air

• Plants are grown in the ground. • Many shapes and sizes


"It's probably more appropriate to look at high tunnels as creating a system, rather

than being an individual technique, because of what they do. They're simple

structures but they create a different farming system. Fertilizer use, crop

protection use, water, equipment use -- they all change.”


Tomatoes



Advantages of High Tunnels

• Generation of Heat Early and Late in the season

• Cold and Weather Element Protection During Winter



• 4-8 weeks earlier production in the spring • 2-5 weeks later possible production in the

fall • Grow crops not usually grown in the area • Very high yield per plant • Crop mix • Very cost effective • Usually no pesticides needed • Organic production



• Natural disease control • Insect control • Control water • Guarantee a crop • Reduce cull fruit.


Concerns of High Tunnels

• Cost involved • Education • Planning • Management • Time


High Tunnel Suppliers

• Nolts • Poly-Tek • FarmTek • Ledgewood • Chamberland • Haygrove • Others


NRCS - USDA

• Has cost share program • Serve every county in US • Check with local office for specific details

















Key Components of high Tunnels

• Good well drained raised soil • Roll Up sides • 6 mil UV treated plastic

• Can be built from many materials





High Tunnel Roof Vent

















Oxygen and plants

• Uptake of nutrients • Root growth • Overall plant growth • Resistance to insect and disease • Fruit yield





Why High Tunnels Work

• Lets review the principles of plant growth Time Heat Light Stress


Time

• All plants need time to advance in growth and mature

• How much growth that occurs in a given length of time depends on how ideal the environmental growth factors are.

• In northern climates heat is the one factor that we need to be concerned about.

• Seed catalogs use maximum conditions in deciding growing days.


Heat

• Plants are classified by there ideal heat requirements.

• Tomatoes , peppers, 80-90 degrees • Cucumber , melons , 85-95 degrees • Heat is measured in growing degree days • Duration of Temperature is Critical


Growing Degree Units

• Normal figure used for warm season crops is 50 low and 86 high

• Growing degree Units = (high for day+ low for the day) – 50 Divided

by 2 (86) (50)


Growing Degree Days units for Tomatoes

• Early to mid-season tomatoes will require 1200 to 1600 GDD to the first ripe fruit.

• Late season varieties will require 2000 to 2200 GDD


Growing degree day samples

Low of 40, high of 60 = 5 GDD Low of 40, high of 50 = 0 GDD Low of 50, high of 70 = 10 GDD Low of 60, high of 86 = 23 GDD


Growing Degree Comparison Inside and Outside Tunnel

• Inside Tunnel • March 281 GDU • April 435 GDU • May 502 GDU • June 570 GDU • July 624 GDU • Aug 544 GDU • Sept 570 GDU • Oct 303 GDU

• Outside Tunnel • March 5 GDU • April 99 GDU • May 183 GDU • June 366 GDU • July 505 GDU • Aug 374 GDU • Sept 396 GDU • Oct 101 GDU


Growing Degree Days units for Tomatoes

• Early to mid-season tomatoes will require 1400 to 1600 GDD to the first ripe fruit.

• Late season varieties will require 2000 to 2200 GDD


High Tunnel Planting Dates

Northern Minnesota • Onions , radishes, lettuce Mar 25-Apr 7

• Cabbage, broccoli ect Apr 7-15

• Tomatoes, peppers April 25 - May

10


Why High Tunnels Work in the Winter • It is not the cold that

causes many or our plants to succumb to winter injury, but the elements of wind, ice and other winter elements.

Overwintering Garlic in High Tunnels

Terrance T. Nennich Extension Professor

Commercial Fruit and Vegetable Production University of Minnesota Extension.

[email protected]


Cold Temperature Data

Days below 0 F Coldest Day 2005-06 17 days -37 F 2006-07 24 days -41 F 2007-08 33 days -38 F The 2006-2007 winter had 8 consecutive night -20F or colder.


Snow Fall Data

• 2005-2006 Ample but below average

• 2006- 2007 Little snow cover

• 2007- 2008 Average snow cover


Survival Rate Outside Tunnel

• 2005 – 06 69%

• 2006 – 07 2%

• 2007 – 08 79%


Survival Rate (%) Inside Tunnel Gothic

• 2005 – 06 94%

• 2006-2007 92%

• 2007-2008 95%









Common Mistakes Beginning Growers Make

• Tunnels get to hot >130+ • Don’t shut roll up sides early enough in the

evening-loose growing degree units 5 GDU a day for a month = 5-8 day • Weed Control inside and out • Monitor the water uptake • Punning and trellising



Tunnel Direction

• Narrow end against prevailing high winds

• The outside air direction has little to do with the cooling of the tunnel

• Recommend tunnel construction for 100 MPH winds.

• Need to consider light needs in winter months





















Yield Potential & Nutrient Needs

• Yields in a high tunnel can be 3 to 4 times the yield obtained in the field

• Higher yields will required more nutrients, but knowing how much to apply is a challenge – Lack of nutrients – deficiencies – Excessive nutrients – salt build up – Both situations affect yield and quality










Solar Heating of the Soil

• Cucumbers – May 15

• Tomatoes – June 5


• Air leaves the solar panels at about 125-175

degrees depending on the amount of sun

• Air leaves the soil at 50 – 75 degrees to be recirculated through the solar panels (this is a closed system )







Results to Date

• Soil temperatures have been kept at

minimum of 52 degrees even though outside temperature have been well below 10 degrees.

• At this temperature, cool season crops are doing very well

Using super oxygenated water in high

tunnel tomato and strawberry production

Terrance T. Nennich, Extension Professor Vegetable and Small Fruit Production

University of Minnesota Extension [email protected]



Tomato research results

• Data was analyzed until mid September and the entire season

• Until Mid September the tomato yield increased 16 %

• No increase in individual tomato weight, large increase in number of tomatoes.

• Increase was less after mid September, cool temperatures.


On line at: www.hightunnels.cfans.umn.edu Minnesota Farmers Market Association 320 250 5087


Minnesota High Tunnel Web Site

• http://hightunnels.cfans.umn.edu/



Seminars on High Tunnels

• Getting Started with High Tunnels • Crops and Yields • Marketing • Soil Fertility/Nutrient Use • Irrigation • High Tunnel design • Organic Production • Fruit Production

QUESTIONS ???????????

Documents

Basics of High Tunnel Production - 2017...Basics of High Tunnel Production - 2017 Terrance T. Nennich Extension Professor Emeritus Vegetable and Small Fruit Production University of