Extending the Market Season with High Tunnel Technology for Organic Fruit Production

Project Overview

Project Type: Research and Education
Funds awarded in 2012: $214,948.00
Projected End Date: 12/31/2015
Region: Southern
State: Arkansas
Principal Investigator:
Dr. Curt Rom
University of Arkansas

Annual Reports

Information Products


  • Fruits: berries (blueberries), berries (brambles)


  • Education and Training: extension, on-farm/ranch research, participatory research, workshop
  • Farm Business Management: budgets/cost and returns
  • Pest Management: biological control, cultural control, field monitoring/scouting, integrated pest management, physical control, weather monitoring
  • Production Systems: organic agriculture


    The goal of this project was to develop high tunnel production systems for blackberries and raspberries that may compliment a field system by extending the harvest season, expanding cropping, improving fruit quality, and be especially adaptable to sustainable and organic production systems. Two field studies using high tunnel technologies and modifications to tunnels were conducted to determine how the technologies may fit into sustainable and organic fruit production systems in the south. The two studies used high tunnels (HT) to 1) advance floricane blackberry harvest and blueberries, and 2) extend the harvest season of primocane fruiting blackberries and raspberries cultivars. Preliminary studies indicated the potential for both. Tunnels were modified to include A) tunnels within tunnels (TnT) around the fruiting plants, B) total screening of the tunnels to exclude insect pests, and C) an overhead micro-fogger system to reduce summer temperatures. Additional studies on the use of shade to delay flowering and fruiting in primocane fruit blackberries were conducted with assistance of the SARE Young Scholar Enhancement (YSE) supplemental grants. Project activities focused on organic field experiments, organic insect pest management practices, developing and testing interactive enterprise budgets for blackberries, raspberries and blueberries and the grower sustainability assessment, Sustainable Blackberries and Raspberries: A Self-Assessment Workbook for Growers, in addition to sharing project results through various outreach and extension methods.

    In the experiment for floricane fruiting blackberries, HT and TNT treatments reliably led to earlier harvest, larger fruit, and higher quality fruit compared to open field plots. TNT provided an extra layer of frost protection and heat retention however issues with inadequate bee pollination, which requires additional study, prevented any significant earlier harvest. Establishment of the organic blueberry trial was problematic, however, project goals were met with a movable HT were placed over an established adjacent organic blueberry variety trial in 2015. HT or TNT advanced blueberry harvest from 0 to 11 days depending on the cultivar. Although HT blueberry yields tended to be higher than FD the difference was not significant, due to a limited number of replication. In the experiment for primocane blackberries, cultivars PrimeArk 45, Prime-Ark Traveler, and APF 205, yielded 2-3 times higher in HT compared to FD and had significantly higher marketable yield. HT and TNT treatments were harvest from one to 5 weeks longer than FD plots when cold temperatures/freezes stopped production. The raspberry study was discontinued in 2014 due to significant plant death. The effects of shade on primocane blackberries in HT was investigated by SARE YSE interns in field and greenhouse studies. In primocane blackberries, shading in mid to late June and mid-July did tend to delay flowering and fruiting, however, it also tended to reduce cropping. In raspberries however shading increasing fruit yield. A micro-mist system was tested on its potential to lower HT temperature and bumble bees were monitored on their habits and frequency of visits to flowers under TNT.

    Over the past 3 years broad mites and spotted winged drosophila (SWD) emerged as key pests that threaten sustainable bramble production. Exclusion insect screen was places on HTs to protected fruit from SWD but the screen offers little protection against mites. Aphids and two-spotted spider mites are two key pests in HT. Various approaches were used to control these pest, organically.

    Three interactive sustainable berry budget tools were developed for blackberry, blueberry, and raspberry, available at www.cars.uark.edu. These tools estimate costs and returns for field and high tunnel production. Berry producers can create complete production budgets for their operation and can perform breakeven, sensitivity and risk analyses to make better production and marketing decisions.

    Project information on organic HT production considerations, insect pest management, economic potential and farm sustainability was extended to current and potential growers, students, and extension educators through presentations at regional annual winter conferences including the OK-AR Horticulture Industry Show in 2013 and 2015, the Missouri Organic Association conference in 2013-2015, a three workshops on high tunnel fruit production with accompanying field tours, a blog, newsletters and national professional society meetings for horticulture, entomology and agricultural economics.

    Project objectives:

    The purpose of this project is to extend the sustainable production of summer berries using HT technology to achieve earlier spring harvest of blueberries and blackberries, and to allow for an extended autumn production of new primocane blackberries and raspberries. The goal of the project is to develop an environmentally and economically sustainable organic fruit production systems combining HT production with traditional FD production and providing for further expansion of organic crop production in the southern region. 

    The specific project objectives were:


    1. To develop High Tunnel (HT) production systems for season extension of organic high value fruit crops for the southern region.
    2. To develop and test pest management strategies for organic HT crop production systems adapted to the southern region.
    3. To estimate economic models and to create decision support tools that help producers to manage production systems for profitability considerations
    4. To extend the knowledge acquired through the production, pest management, and economic analyses into a multi-dimensional educational, outreach, and extension program.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.