Final report for FNC21-1302
We are a small, 5-acre farm that serves the city and suburbs of Cincinnati with local, fresh, and sustainable products through direct sales and our local farmer's market. We grow a variety of vegetables without the use of chemical pesticides, herbicides or a tractor and with an emphasis on practices that build soil health. Typical varieties of vegetables include lettuce, kale, green beans, cucumbers, tomatoes, peppers, watermelon, squash and pumpkins. We also have a small dairy goat herd and a flock of egg layer chickens that allow us to sell goat milk soap and free range eggs. We have been using our sustainable practices for just about 10 years and are members of the Ohio Ecological Food and Farm Association (OEFFA) and the American Dairy Goat Association (ADGA).
Controlling pest damage in vegetable production has long been a challenge for farmers and gardeners in all areas, especially in organic and sustainable agriculture systems. Use of chemicals, even organic options, have real disadvantages for the producer and the customer.
Studies have shown that having diversity when planting can lessen pest damage, but the exact reasons why have not been well understood. The Appropriate/Inappropriate Landing theory (Finch, Collier) says that pests follow a three-step process when selecting a host plant: Traveling to an area with the host plant via specific odors, using visual stimuli to land on a green surface, and making a few short flights to neighboring leaves. To be successful, the insect must make consecutive "appropriate" landings on a host plant to stimulate egg laying, non-host "inappropriate" landings resets the egg laying process.
We are proposing that this theory provides a sustainable way to lessen the damage made by pest insects, without the use of chemical insecticides. We would investigate the various companion planting options for pumpkins to provide sustainable options that would be low-cost, lessen labor inputs, and be effective against extensive pest pressure.
- Interplant 5 different companion planting options for pumpkins. Companion plants include Nasturtium, Crimson Clover, Cereal Rye, Buckwheat and an artificial greenery option, over bare soil to evaluate pest damage and pressure.
- Compare companion plantings to artificial greenery to evaluate effectiveness of Appropriate/Inappropriate Landing theory in pumpkin production.
- Identify most and least effective options for insect pest damage control of companion planting options.
- Present research at annual OEFFA (Ohio Ecological Food and Farm Association) conference, information session, and website.
Since we will be measuring pest pressure and damage in pumpkin plantings, we want to eliminate as many unwanted variables as possible. So we will be using a rectangular portion of our larger field that has not had vegetables planted in it, and has only been used for grazing in 2020. This portion of the field is approximately 140' x 45' and would be without any previous pest problems. We would then plant several hills of the same pumpkin variety. With each hill, we would then seed around the hill and projected areas the vines would reach with selected companion plants. We would additionally have a control hill, a hill with artificial greenery, and a hill with a diverse mix of several of the companion planting choices. The artificial greenery would address the Appropriate/Inappropriate Landing theory's findings of artificial greenery. To plan for poor seed germination or other issues that may arise from the chosen pumpkin variety itself, we would also be selecting additional varieties of pumpkin to use in the same fashion.
After the first true leaf emerges, each plant will receive a weekly score from 0-3 (0 being no damage, wilt, or discoloration, 1 being minor, 2 being moderate and 3 being major damage, wilt, or discoloration) in 3 categories: leaves, vine and fruit. Additionally, plants will be inspected for eggs, nymphs and adults of insect pests twice weekly and noted for each plant. This will allow us to monitor if adult insects are landing on the pumpkin plants, but also staying to feed and lay eggs as well. At the end of the growing season, we will compare to see if all greenery is effective or if certain companion plantings work better than others.
The results that we received are mixed, depending on the insect pest observed. With Squash Vine Borers, we found that all of our companion plantings (Nasturtium, Crimson Clover, Cereal Rye, Buckwheat) were equally ineffective. However, in regards to Squash Bugs, we found that buckwheat did a much better job at minimizing pest pressure than the others, even as other neighboring plots struggled. Since the feeding and lifecycles are somewhat different between the two, there could be a variety of reasons as to why the two insects had different results.
To summarize the data we collected, we measured pest damage on a 0-3 scale (0 meaning no damage, 3 being heavy damage) on both leaves and vine health. From a mid-June planting, we saw only 0's and 1's until mid July, when the Squash Vine Borer larva became too much for the vines to handle on many of the plants and yellowed out, stunting all growth and fruit development. The squash vine borers killed many of the plants, regardless of cover crop treatment. With the plants left, we measured pest damage still, but also the number of eggs laid on the leaves. In August the Squash Bugs arrived. We found that, perhaps due to the rapid growth, buckwheat sheltered the pumpkins and vines from infestation almost to zero further damage through to September. The other plantings were not as successful (see attached data). The rye may have been more successful if planted much earlier than the pumpkins to allow it to establish and mature taller. The nasturtium and clover were low lying cover crops that did not successfully deter pests well. The artificial plants were placed at a height that was appropriate at first, but the pumpkin foliage did grow up and over the treatment.
Educational & Outreach Activities
We have communicated our research information to customers that attended the October farmer's market that we attend and also presented at OEFFA in a virtual session, which was a NCR-SARE Farmer's Forum in February.
The virtual session was live and according to the Socio app used by OEFFA, 28 attendees participated. The recording is available for all OEFFA 2022 conference participants for 3 months after and participating in the SARE Farmer's Forum will allow more to view beyond this date as well.
Our results and information were presented to the OEFFA conference in February, where many more farmers will gain KASA (changes in Knowledge, Attitudes, Skills and/or Awareness) for sure.
I learned a lot from this grant, even if the outcome is not at all what I was expecting. We learned that because insects all have different lifecycles, they visit crops at different times and with different motives (feeding, egg laying, ect). As such, companion planting may be more tailored to the specific crop AND specific insect than we first thought, finding the perfect "dance partner" for your cash crop. With Squash Vine Borers (SVBs), we found that all of our companion plantings were equally ineffective. We wonder if, because we were walking near the base of the vines so often in checking for pest pressure in the same path, we actually created space for the SVBs to find the base of the plant easier where the larva burrows into. However, in regards to Squash Bugs, we found that buckwheat did a much better job at minimizing pest pressure than the others, even as other neighboring plots struggled. The Squash Bugs came later in the season, when buckwheat was much higher and, those that could surrounded the pumpkin foliage and vines better. We predict that rye would be more effective if planted well before the pumpkins are, to allow it to establish further and mature taller to better cover the pumpkin foliage from pests.
We did not eliminate pumpkin pest pressure, but now better understand some of the relationships and possibilities in lessening the damage done. I would tell other farmers to try and find a companion plant that works together with your crop plant to surround it, but not outcompete it. Anecdotally, the cash crops mixed in to the buckwheat, near the same height as the host plant did much better in resisting pest pressure, in regards to squash bugs. In the case of pumpkins, buckwheat may be a good find to look further into. To apply the same principles to other cash crops, finding a companion that grows well during the same grow season and around the same height would be ideal.
I believe that this study is just the tip of the iceberg for researching pest insect control using their own behaviors and I would like to build upon this study in the future knowing what I know now. Could be applied to almost any crop/pest relationship. SARE has been a wonderful partner and service to agriculture in whole.