Can Screened High Tunnels Extend the Growing Season of Bitter Melon in the Midwest?

Final Report for FNC05-551

Project Type: Farmer/Rancher
Funds awarded in 2005: $6,000.00
Projected End Date: 12/31/2007
Region: North Central
State: Kansas
Project Coordinator:
Pov Huns
Huns Garden
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Project Information


Huns garden is an all natural farm that is operated by Pov Huns and Chaxamone Lor (husband and wife), who grow vegetables and herbs on 3.95 acres located in Urban Kansas City, Kansas at Huns Garden. We grow over 40 different varieties of small fruits and vegetables. Over half of our crops are specialty vegetables that have medicinal values, and other Asian greens that are hard to find. We serve a diverse customer base including immigrants from Africa, Asia. Caribbean, Middle East, Pacific Island, and South America; as well as locals interested in healthy eating.

Before receiving this grant we carried out many sustainable practices involving mulch (living mulch, wood chip mulch, and plastic mulch). This is one of many projects which we would like to introduce in the Midwest with the practice of growing tropical plants in a non-tropical environment.

Our project goal was to see if screened high tunnels extend the growing season of Bitter Melons in the Midwest. Also, we wanted to see whether pest control and season extension could make tropical vegetables (Bitter Melons) profitable by using a high tunnel on our Kansas City farm.

The overall goal of the project was to develop a set of practices that would permit the production of high quality bitter melon during the entire summer and fall in the Midwest. We evaluated bitter melon varieties to assess their cold tolerance and production potential in the Kansas City area. We also investigated the potential of screened high tunnels to keep out pests and increase temperature to promote crop growth. The project took place over two growing seasons, with the second year further developing and refining the procedures from the first year.

First year production:
In our first year of production, we conducted our experiment as follows:
1. Purchase a small green house. Start seeding in early March with the aim of early April transplants for an early jump start into the growing season.
2. Purchased a high tunnel; screened the sides and ends of tunnel to keep insects out by the end of March.
3. Divided the interior into plots and randomly planted in 4 plots per variety (discussed with Ted Carey, K-State vegetable production specialist, about the appropriate design of the experiment in the high tunnel).
4. Two plots of each variety were used for fruit production; the other two sets were for leaf production.
5. 7’ T-posts were set 6’ apart to be used as trellis support (approximately 6’ above ground) with twine weaving to form a mesh netting to support the vines and to increase the growing space inside the high tunnel with floating cover suspended on top of the T-posts during the cold season.
6. Each plot had drip irrigation buried 1-2” below the soil surface and plastic mulch was used to help elevate the soil temperature and control weeds.
7. Bees were used for pollination, and lady bugs and other control measures were used as required to control aphids and other greenhouse pests.
8. An outside control plot was directly sown in the field. Straw was used as mulch to conserve moisture.
9. Data was taken from each plot with interest in early plant survival and quality as well as quantity of fruit and leaves over the course of the season.
10. For fertilizer, we used chicken manure as fertilizer in the beginning of the season. After July, fish emulsion and kelp was applied once every month throughout the growing season.
11. In the second year, we anticipated using fewer varieties and improving our structure as needed to adjust for any deficiency from the previous year.

Second year production
1. We followed the same process as we had in the first year except we grew only 5 out of the 17 different varieties of bitter melons. We planted each variety in two different plots.
2. We stopped using the bumblebees in the high tunnels, while increasing the honey bees on site from 4 hives to 16 hives in hope that some would go into the high tunnel.
3. We did not set up the screen and do not plan to harvest leaves in this second year of production because it proved to be counter productive in the first year of production.
4. Increased plant spacing between plants from 2' to 3' apart with the hope of increasing visibility, increasing the size of fruit and reducing time on harvest.
5. Fertilization and irrigation remained the same as the previous year.

In our first year of production, we received help from the Kansas City Center for Urban Agriculture (KCCUA) on the building process of the high tunnel. Three farmers showed up to help put up the structure. During the first season, the KCCUA helped us organize the farm tour. Twenty-five people visited the farm.

In our Second year of production, we received help from the KCCUA which allowed us to use their greenhouse for the hardening off process during our seeding process. Also, KCCUA helped us organize a farm tour with a cooking demonstration and cultural music at the farm. Two hundred fifty people visited our farm.

First year results
1. The survival rate of transplants older than 4-6 weeks was fairly low -- the initial transplants had a 50-80% transplant failure rate.
2. The survival rate of transplants that were 2-3 weeks old had a better survival rate than the 4-6 week old plants. Their survival rate was about 50-75%.
3. The survival rate of transplants that were 1 week old had the best survival rate overall (80-90%).
4. The 4-6 week old transplants were harvested 1-2 weeks before the other transplants. The 2-3 week old transplants and the 1-week old transplants showed no significant time difference between their harvests. Overall, the transplanted bitter melon plants had a 2-3 week earlier harvest than the direct-seeded control plot.
5. Planting inside the high tunnels somehow caused the bitter melon leaves to become very bitter but made the fruit lighter, so customers tended to buy more fruit due to volume per dollar, but stayed away from the leaves. The leaf production process had to be abandoned, because most customers who bought them came back and complained that they tasted too bitter.
6. Excessive heat built up in July and August so the side screen and the side cover had to be removed to ventilate.
7. These old plants survived the initial fall frost, but died during the following hard freeze when the moisture was trapped on the roof and formed ice that dropped back down on the plants.

Second year results
1. Increasing the space between plants increased the visibility of these fruits to where it was easier to harvest; but it had no effect on the plants’ survival rate in the beginning of the transplanting process or the winter survival rate.
2. The down side of increasing space between plants was that it also increased the heat available inside the high tunnel. The high heat and high humidity caused these fruit to prematurely ripen. We lost up to 50% of our fruit from the month of July thru October. For example, for every two bitter melons that we picked, we kept one and threw away the other one.
3. Among all the premature ripe fruit, most of the ripe fruit were hanging above three feet.
4. The results of the plant selection for this second year trial are as follows:
Ratings 5=best 3=average 1=poor

Plant Varieties, Productivity, Heat Tolerance, Cold Tolerance

Large Top (smooth and short) 2 2 2
Jumbo Thai (smooth and long) 3 3 3
Indian Queen (spiny and long) 4 4 4
Indian Baby (spiny and short) 5 5 5
White Star NS (white bitter melon)1 1 1
5. Based on the result of these two growing seasons, I believe we have achieved what we intended to do on this project. We can see that even with the draw backs, we still get roughly twice the quantity, as well as the quality compared to the conventional system of growing based on the same square footage. However, we still think that there is more improvement needed for growing bitter melons in high tunnels.
6. The down side of this project is that we had very high expectations for leaf production, but it turned out to be very poor. These leaves became too bitter and we couldn’t sell any, so we had to abandon this part of the experiment within the first two months of production. Also, we expected to put in a well and a solar water pumping system that would have helped us to be self sufficient, but within a month of completion, we realized that the well went dry, and found that the well driller sold his business and retired.
7. Moreover, the screen high tunnel has proven to be an unsuitable environment due to high heat, low moisture, and low pollination, which leads to premature ripening of fruit and increases bitterness of the leaf.
8. If we had to do it over again, we would be more prepared this time around. We would need to have shade cloth ready to use starting in the middle of June before it turned really hot in July. (The reason that we did not use this process in our second season is that we expected to thin our plants in hopes of increasing air circulation so that we wouldn’t have to use shade cloth; but it still failed to increase circulation sufficiently. Instead, we lost half of our crop before we realized that we needed to change to shade cloth. By this time, we had checked into getting shade cloth, but it would take six to eight weeks before we would get the shade cloth, so at this point, it was too little, too late). Also, we would prefer building a two layer plastic high tunnel instead of one, but the bad news is that we do not have access to a power source, which would allow us to inflate the two layers of the plastic. We suspected that we could have extended the growing season a little bit more if we could have built a double layer or inflated high tunnel. (The reason behind this train of thought is that ice is forming on top of the high tunnel and falling back down onto the plants during the cold season. This process caused the plants to die during the initial freeze and the first hard freeze).

1. What we learned from this grant project is that we can grow tropical plants in the Midwest with some know-how and some technology that already exists such as high tunnels, shade cloth, row cover, and drip irrigation. In this manmade environment, we can better control the environmental conditions and grow our bitter melons in this project. This forever will change our approach to farming in this area. We will definitely change our process of cultivation, along with the harvesting process so that we can continually improve our way of farming in order to meet or exceed our customers’ expectations. With this fresh in our minds, we will use this technique to explore other possibilities of bringing other tropical vegetables and herbs into this region.
2. The highest obstacle that we have is cost control. This is an ever-growing problem for a new project such as ours. The initial investment proved to be a little bit more than expected in this project, as well as the cost for subsequent improvements and fine tuning. At times, we noticed that everything that we needed for the experiment was not readily available (i.e. back orders on some of the material such as shade cloth which was needed in the hot summer. We failed to acquire the shade cloth because the vendor that we approached was back ordered and we would not be able to get it for at least a few months).
3. The advantages are that it provided a semi-controlled environment which allowed us to work whenever we wanted, and to fit work into a convenient schedule regardless of the weather outside.
4. The disadvantage of this type of project is that the initial cost is usually under estimated because the raw material is always on the rise. As a farmer, I can see that even with a well thought out experiment like ours, it seem to be over run with raw material costs and unexpected weather changes which are always an unforeseen situation which is hard for us to cope with. Also, the initial cost is fairly high so it makes it hard to justify some of the spending money. Since we finished our experiment in the two year period, we have still not been able to earn back our expenditures; so it is hard to justify this type of experiment. In other words, the cost is clearly exceeding our benefit at this point. As far as recommendations concerning this type of project, we would recommend that one needs to see if one has the resources to maintain this type of project for a longer period than we did. For example, if one is looking for a short-term goal in hopes of recapturing the expenditures with in a year or two then this type of experiment is clearly not suitable. If one is looking for a long-term investment, over five years or longer, it might be a profitable project.

The following economic analysis is based on our experiment selling produce at a large farmers market in Kansas City, Missouri, where competition tends to be strong in terms of price. There is a lot of shipped-in produce and early high-tunnel produce from local farmers does not fetch a price premium.

Based on our first year’s data, we had similar yields from both conventional production and the plants grown inside the high tunnel. Based on our sales records and labor records, it seems that this project has clearly cost more than the benefits which we expected to gain. With the exception of the working conditions in the field, and meeting our customers’ demand for early produce, the economic feasibility of this system of growing is less suitable compared to the conventional way of growing bitter melons. With this in mind, it is clearly more suitable to grow bitter melons in the open field than to grow them inside high tunnels.

Organic growing methods and biological and mechanical management systems that we used resulted in minimum environmental impacts. The only impacts that we have seen so far are land erosion around the high tunnel, but with good land management techniques this has become a lesser problem (when we noticed there was land erosion around the base of the high tunnel, we gently let a small strip of grass grow around the high tunnel, and this has solved the problem). The good news of this project is that we are able to meet our consumer demands for this produce and this project has helped us move our consumers further toward a local sustainable food system.

The social impacts of this project are quite positive in terms of meeting our local market’s demand. Even though this type of system is not suitable for short-term investment, it is suitable for long-term investment. As a long-term investment, local farmers in this region can bring in a greater selection of vegetables, which could encourage individuals to increase their support of the local organic vegetable grower’s way of life while improving the health of the individuals who eat these specialty vegetables.

In 2006, the information from our project was shared with others as follows:

1. A field day with cooking demonstration in August -- 25 people attended
2. A documentary film by Ana Sofia Joanes of Ripple Effect Films made onsite following the field day.
3. October Kansas City Wellness Magazine article about Medicinal Vegetable (bitter melon) by Dr. Bethany Klug, DO.
4. A presentation of the project at the Farmers Forum at the National Small Farm Trade Show & Conference in Columbia, MO on November 4, 2006.

In 2007, the information from our project was shared with others as follows:
1. January 2007, we give a presentation at the Great Plains Vegetable Conference
2. June 2007, field day with cooking demonstration -- over 250 people attended
3. July 2007, a follow up from GRIT Magazine staff (Jan/Feb 2008 magazine article) and Herb Companion Magazine staff from the farm tour, will be available for the 2008 issue
4. A summary presentation of the project at the National Small Farm Trade Show and Conference in Columbia, MO in November 2007
5. A summary presentation of the project was given to the Kansas City Center for Urban Agriculture (KCCUA) in December 2007.
6. An archive of the presentation is being made available thru the KCCUA on their website
7. Will be available for the SARE National Conference Farm Tour in March 2008.


Participation Summary
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.