An alternative organic strawberry production system grown vertically in high tunnels

View the project final report

Commodities

• Fruits: berries (strawberries)

Practices

• Crop Production: fertigation, irrigation, organic fertilizers
• Education and Training: on-farm/ranch research
• Farm Business Management: new enterprise development, feasibility study
• Pest Management: biological control, integrated pest management, sanitation
• Production Systems: organic agriculture
• Soil Management: organic matter, soil quality/health

This project was designed to address two issues facing sustainable fruit production in the South:

1) Season extension of strawberries with cultivar selection and management practices.

2) Methods to increase the production area of a hightunnel (HT) by testing strawberry production in an elevated system over in-ground beds.

High tunnels offer protection from frosts and rain resulting in minimal disease pressure and improved fruit quality and quantity.  Additionally, HT extend the cropping season with little or no added heating energy.  HT production is still relatively new technology in the U.S. and many producers struggle to utilize these structures to their full capacity.  One area of optimization exists in improving the use of the vertical space above the growing beds, which is often not used at all.

Strawberries are an ideal crop to investigate the potential of an elevated production system in a HT.  Strawberries are compact, can be managed to produce fruit in the off-season and HT are believed to have a positive effect on yield (Demchack, 2009).  In addition, strawberries can be grown in an elevated, HT system without the high inputs required in a typical commercial system such a sfumigation and plastic.  Also typical of commercial production, the fruitis marketed on a relatively short time frame, from 4 to 6 weeks, in April through May, in Arkansas.  This concentration of production creates a sub-optimal situation where strawberries show up simultaneously in the marketplace, therefore limiting prices and profits.  With cultivar selection and high tunnel management practices, it is possible to extend production into the off-season.

The two primary means of strawberry season adjustment are high tunnels and genotype selection.  Day-neutral strawberry varieties do not require specific day-lengths to initiate flowers and set fruit as long as temperatures allow (Ballington et al., 2008).  Growers in many parts of the United States use day-neutral strawberries to produce high-value fall crops.

The grower-collaborator (Gros, Foundation Farm) of this proposed project toured small sustainable farms in France and learned of their production system.  This system involves growing strawberries, year-round, in an elevated system in high tunnels.  The production system for this project relates to this design.  Gros's high tunnel is a standard 30'x96' design with approximately five 4-ft wide beds and four 3-ft wide paths.  A strawberry support system was used over the beds with easy reach from the path.  Wood-frames were constructed over the length of the beds with suspended cradles made of metal tubing/rod.  Two lines side by side will be suspended over the three middle beds for a total of six lines.  “FiltrexxSoxx” soil-tubes were laid inside the metal cradles, and filled with compost.  Strawberries were planted inside the tubes along 2 parallel lines at 1 foot interval, for a total of about 192 plants per tube and roughly 1200 plants in total for the high tunnel.  Soil tubes were equipped with drip irrigation for an even distribution of the water through the tube.  The water was already at the site with enough pressure to satisfy the elevated tubes.

Plants were grown in-ground in the high tunnel as a control production system.  Two day-neutral cultivars 'Radiance' and 'Festival' were tested using three planting dates: late July, late Aug and late September.  The cultivars 'Radiance' and 'Festival' were selected because they have performed well in previous high tunnel research at the UA.  Because the best planting dates to maximize season extension are unknown, three planting dates were used.  Project plans were to compare results to a similar project underway at the UA.  This project involves growing in-ground, day neutral strawberries under high tunnels, with multiple planting dates and conventional fertilization.

Extend the production season of strawberries by managing with cultivar selection and planting dates.  Two day-neutral cultivars, 'Albion' and 'Festival' were selected because they have performed well on preliminary UA research of off-season high tunnel strawberry production.

Determine the effectiveness of increasing the production area under a high tunnel by comparing strawberry production in an elevated system to in-ground beds, all under a high tunnel.