Improving farmer options for sustainable and profitable direct-market tomato production and high tunnel management in the Upper Midwest

View the project final report

Commodities

• Vegetables: tomatoes

Practices

• Crop Production: crop improvement and selection, high tunnels or hoop houses, plant breeding and genetics, season extension
• Education and Training: on-farm/ranch research, participatory research
• Pest Management: genetic resistance
• Production Systems: organic agriculture
• Sustainable Communities: local and regional food systems, public participation

Tomatoes are a key crop for organic and diversified fresh market vegetable growers in the North Central Region (NCR). Growers face challenges with field tomato production, due to short seasons, increasingly erratic weather producing larger rainfall events, and high disease pressure. Many growers have begun using high tunnels as a partial solution to these problems, because this  offers some protection from high rainfall events and foliar disease while extending the growing season. However, high tunnels come with challenges of their own, particularly stationary high tunnels that reduce growers' rotational options. Mobile high tunnels allow for rotation and soil building practices, but are more expensive than high tunnels. Caterpillar tunnels may provide some of the same benefits as mobile high tunnels with a much lower cost but this has not been tested in the NCR.

In addition, tomato varieties developed specifically for field and the high tunnel production would benefit growers in the NCR. This includes varieties bred for organic field environments, with better combinations of flavor, disease resistance, durability and resistance to cracking than current options, and varieties developed specifically for high tunnel production, with more concentrated fruit set and shorter production seasons, to allow for rotation to a cover or winter crop without sacrificing flavor, quality or overall yield.

This project is designed to address the challenge of producing high quality tomatoes organically for local markets in the NCR by comparing production, disease mitigation and cost in high tunnels, caterpillar tunnels and field production, so growers can base management decisions on reliable information about the benefits and drawbacks of each system and selecting early tomato varieties for high tunnels, with improved flavor and more concentrated fruit set to give growers more rotational options in high tunnels and selecting tomato varieties that are more robust for the field, with improved disease resistance and flavor. These build on our current work and respond to grower needs. We relied on participatory research with growers, including on-farm trials managed by growers and on-station trials advised by growers. This project involves farmers in both the management trials and in variety selection. Outcomes from this research will include information on the relative costs and benefits of different management systems, advanced tomato breeding populations developed for organic field and high tunnel production, and a stronger network of participatory research and farmer-focused cultivar development in the NCR.

For tomato production the high tunnel and caterpillar tunnel both had significantly higher marketable yields than the field production system in both locations.  However, as there were system-specific differences in the prevalence of certain causes of unmarketability, such as blossom end rot, choosing varieties that are less susceptible to these particular problems for specific systems may be beneficial to growers. Both tunnel systems had higher ˚Brix levels compared to open field but there were no significant differences between tunnels. This may be explained by the higher temperatures and lower soil moisture levels in both tunnels compared to the open field. The tastings confirm what was found in the ˚Brix and CA, with higher perceived sweetness in the tunnels compared to the open field, and higher acidity in the open field compared to both tunnels, with no significant difference between tunnels. The high tunnel and caterpillar tunnel both showed a significantly higher overall flavor rating compared to the open field. Caterpillar tunnels require a significantly smaller initial investment compared to high tunnels, due to lower purchase and installation costs and produce similar benefits in terms of production and quality. A drawback of caterpillar tunnels is the significant time needed for ventilation, and innovations for less labor intensive ventilation systems would be welcome.

In the breeding component of the project we evaluated crosses between many parents chosen for performance in the high tunnel and the field.  We selected based on production, disease resistance and fruit quality traits, resulting in lines from 7 different families being advanced. We evaluated 22 tomato breeding lines and commercial varieties in a replicated trial in 2020 and 2021. The breeding line had a significant effect on all the production traits, early blight and leaf mold and on all the fruit quality traits except for bitterness. The productivity of the breeding lines was lower than the check varieties, but the genetic variance for most traits of interest and heritability were both high. This indicates room for improvement in these traits, although with the caveat that these calculations are based on a single location and a single year. Their was a negative correlation between marketable weight and the fruit quality traits will be a limitation for future selections.We also had disappointing field performance in the face of severe disease pressure and are planning to also incorporate single-gene resistance in future breeding lines for early blight and septoria. Next steps for this project include trialing lines in more locations and farms to determine if they should be released. Promising lines could also become parental line material for future breeding programs.

This project developed new breeding populations of tomatoes with excellent quality and adaptation to organic diversified vegetable farming in the upper Midwest. We also provide recommendations on the use of lower-cost mobile alternatives to high tunnels. We aim to develop better variety options for high tunnel production and for field production, with traits specific to those systems. We have strengthened our current on-farm trial network to continue to support peer-to-peer information sharing among growers. This will help farmers meet market demand for high quality local produce.