Open Field vs Protected Culture Production
For over a decade there has been a global trend toward protected culture of commercial fresh market tomatoes vs. open field production. This trend started in Europe with large scale producers and has since spread to North America1. The economics of such a transition has been compelling for large scale commercial producers. This piece is designed to help small/medium sized market producers determine whether transitioning all or part or their open field production to protected culture makes sense for their operation.
Protected Culture Options and Best Practices
Tomato is the most widely grown high tunnel and greenhouse vegetable crop because of strong consumer demand for the high-value fruit, and the ability to extend the growing season.
Protected culture tomatoes are grown in a wide range of structures from simple row covers to hoop-houses and high tunnels to more expensive greenhouses with permanent foundations. The most elaborate greenhouses may have supplemental heating and/or lighting.
There are numerous online resources that outline cultivation best practices for each of these protected culture options. Most of these are designed for small/medium sized producers2.
There is also a recent book “The Greenhouse and Hoophouse Growers Handbook” by Andrew Mefford that outlines best practices for multiple vegetable crops, including tomatoes.
Data from Comparisons
Although the general benefits of protected culture production have been well documented, including:
- Extended growing season
- Increased yield of marketable fruit
- Improved disease control
There are also increases in labor cost, a requirement for irrigation, and the capital cost of the high tunnel or greenhouse.
Unfortunately there are not many studies that provide good economic comparisons of open field vs protected culture practices. In a multi-year study (2014-2016), researchers from UW-Madison evaluated 15 different tomato varieties for performance in high tunnel and open field management for marketable/ unmarketable yield, average fruit weight, fruit number, and disease incidence. This study showed significant economic gains with hoop house production3.
Researchers at Washington State University did similar comparisons with greenhouse vs open field tomatoes and lettuce. They found very significant increases in yield for both with greenhouse production, but that with lettuce the increased labor associated with greenhouse production was higher than the value of the production increase. There was also a significant labor increase with greenhouse tomato production, but it was more than paid for by the value of the tomato production increase4.
In a third study U of Tennessee researchers found an increase in fruit marketability and size with GH vs open-field production, and a significant decrease in leaf disease. They only found a fruit yield increase in GH production when GH cultivation allowed an earlier planting date5.
- Linda Calvin, Suzanne Thornsbury, and Roberta Cook; United States Department of Agriculture, Economic Research Service
- Agricultural Extension Service, The University of Tennessee; New England Vegetable Management Guide;The Greenhouse and Hoophouse Growers Handbook by Andrew Mefford
- Terry Hodge, Kitt Healy, Brian Emerson, Julie Dawson University of Wisconsin-Madison, eOrganic
- Suzette P. Galinato, Carol A. Miles, HortTechnology
- Mary A. Rogers, Annette L. Wszelaki, HortTechnology