Maypops, a New Fruit Crop in Wisconsin

View the project final report

Commodities

• Fruits: general small fruits

Practices

• Education and Training: farmer to farmer, on-farm/ranch research
• Farm Business Management: new enterprise development, budgets/cost and returns, marketing management, feasibility study, agricultural finance
• Production Systems: organic agriculture

This project evaluates the maypop, a temperate-zone relative of the passionfruit, as a new fruit crop for hoophouses in Wisconsin and the North Central region.

Problem/solution: One problem is that the market for local produce is crowded and that many produce growers in our region seek new and alternative crops to distinguish their farms in the local marketplace and to diversify their sources of income. A second problem is that there are few cultivated fruits suitable for our climate: growers seeking to produce fruit for local markets have limited options. (This is also a problem for stores and consumers who would like to purchase locally grown fruit but have few choices).
I propose to evaluate the maypop as a potential new fruit crop in our region to address both of these problems. The maypop is an excellent candidate for a new fruit crop: (1) it is closely related and very similar in appearance and taste to the widely-grown tropical passionfruit, (2) it has a long history of being eaten as a wild fruit where it is native in the southeastern United States, (3) it is similar in growth habit and cultural requirements to the cucumber and tomato, crops which many growers in our area already have experience with, and (4) it is unrelated to most crops grown in the region and would thus diversify crop rotations.
From a farmer’s standpoint, a major barrier to raising a new crop such as the maypop is the lack of information: growers do not know basic information about the cultural requirements of the maypop and the potential profitability of raising it. I propose to collect and disseminate this information.
The specific goals of my project are: (1) Collect data on expenses (including labor) and yields to evaluate the profitability of organically-grown maypops in hoophouses (a.k.a. high tunnels). Maypops are a heat-loving crop, benefit from a long growing season, and are likely well suited to hoophouse cultivation. (2) Compare winter survival of maypops in a hoophouse when they are covered and uncovered by fabric cover and compare yields and profitability in the first and second year after planting. The maypop can be grown as an annual because it will flower and fruit prolifically in its first year, and as an annual it would fit best into crop rotations on many vegetable farms. However, it may be more profitable as a perennial if yields are higher in the second year or if the expense of establishing new plants is high. If the maypop is best grown as a perennial it is important to know whether covers are needed for overwintering within a hoophouse in our region. (3) Compare yields of hand-pollinated and non-hand-pollinated maypops to determine if lack of insect pollination limits yield in hoophouse maypops. If so, future research could evaluate managed bumblebees or other introduced pollinators. (4) Compare yields and growth of maypop plants from several seed dealers and nurseries. There are no named maypop varieties, but clones from some sources may be better suited to our region. (5) Assess consumer and chef acceptance of maypops. I will provide free maypop fruits to a local grocery store and restaurant and also to a sample of our CSA members and solicit feedback.
Specifically, I will source maypop seeds and root cuttings from ten commercial sources and raise young plants in pots in heated greenhouses. I will transplant 120 plants (12 from each source) to a 16’ x 132’ hoophouse after danger of frost in the hoophouse has passed. Plants will be raised on trellises in rows four feet apart, plants spaced three feet apart within the rows. I will randomly divide plants from each source among four experimental treatments: covered/ hand-pollinated, uncovered/hand-pollinated, covered/unpollinated, and uncovered/unpollinated. Plants in the covered treatments will have their roots covered by heavy fabric row covers after the tops have died from frost (the natural growth habit of the maypop is that the aboveground parts die each winter but the roots survive and grow new shoots in the spring). Plants in the hand-pollinated treatments will have all of their flowers hand-pollinated during the growing season.

Research: I have read extensively about maypops in scientific journals and in fruit growers periodicals and I have corresponded and spoke with several maypop growers. My proposal builds on and expands previous work:
1. Growers in New York State, Kansas, and Tennessee have grown trial plantings of maypop fruit, but no one has rigorously measured and reported expenses in a commercial planting and there is only one report of fruit yields in a cultivated planting. Our research will be the first to report both expenses and yields. This information is very important for evaluating the maypop as a potential crop.
2. When maypops have been cultivated outdoors in central New York State and in Kansas, yields are limited by the short growing season – frost kills the vines before many fruits are mature. Trials have also shown that maypop plants typically do not overwinter in Wisconsin or central New York State. This research will be the first to evaluate maypops grown in a hoophouse environment to both extend the growing season and moderate winter temperatures.
3. Several studies have shown that maypops are self-incompatible (maypop plants cannot pollinate themselves). The most effective pollinating insects are large bees, especially carpenter bees. Small bees such as honeybees visit the flowers to collect pollen and nectar, but the flowers are so large and the parts of the flower so far apart that small bees rarely touch the female parts of the flower and deposit pollen there. Some cultivated maypop plantings receive few visits from large bees and the vines flower profusely but set few fruits, suggesting that poor insect pollination may limit fruitset. Insect pollinators are often scarce in hoophouses, and so poor pollination is particularly a concern in hoophouse-grown maypops. I will test whether pollinators limit fruit yield in my study by comparing yield from hand-pollinated and non-hand-pollinated plants.

Outreach: In 2013 I will hold a field day on our farm in late summer to display the maypop planting to other farmers and to discuss research results. I plan to have fruits available for tasting. Two area non-profit organizations which are heavily involved in farmer training have agreed to co-sponsor the field day: CRAFT (Collaborative Regional Alliance for Farmer Training, based in Caledonia, IL), and MACSAC (Madison Area Community Supported Agriculture Coalition, based in Madison, WI). The field day will be promoted through the MACSAC and CRAFT mailing lists and events calendars, and I will also publicize the day through other regional events calendars and email discussion groups.
I hope to present results from my study at the research poster session of the annual Organic Farming Conference held in La Crosse, WI. This conference attracts 3000+ attendees. Permission to present at the forum is awarded on a competitive basis; I have contacted the conference organizers and they said that my research would be well suited for presentation there.
I will submit the results of my research for publication in Pomona, the publication of the North American Fruit Explorers, which is read by fruit growers interested in new and unusual fruits.
I will publish data and pictures from my study on our farm website, www.twoonionfarm.com, in a portion of the site which I will establish specifically for this study.

Evaluation: To assess profitability of maypop growing, compare plants from different plant sources, measure overwinter survival with and without cover, and test for pollinator limitation of fruitset: I will track expenses, including seeds, plants, and materials. I and employees who assist in raising the maypops will use data forms to record the date, hours worked, and tasks performed on each day that we work in the maypop plantings. I will record dates of planting, transplanting, trellising and other important cultural operations, as well as the dates that plants begin flowering and die from frost. I will record yields (number and weight of fruits) and harvest dates. In the second year of growth I will also record data on winter survival and the dates that plants emerge in spring. All data on plant growth and fruit yield will be recorded separately for plants from each source and for plants from each experimental treatment. I will enter data into a computer database and summarize the results for different plant sources and experimental treatments. I will take pictures of the plants at different stages of growth, of harvested fruits, and of insect pollinators and pests.
To assess consumer acceptance: I will provide a survey to the chef, grocery store produce manager, and CSA members to whom I provide sample maypop fruits. These surveys will ask questions about flavor, ease of preparation, and appearance. I will also keep a log of comments I receive from consumers outside of formal surveys.
To assess my outreach activities: I will record attendance at the on-farm field day. I will collect contact information from field day attendees and send them a survey afterwards to ask whether they will consider raising maypops on their farm, what they learned at the event, and what barriers they see for raising maypops commercially. I will track data on website hits for my research results web page. I will also keep a log of comments I receive from correspondents, field day attendees, and others outside of formal surveys.