The New Agriculture Network's on-line newsletter with seasonal advice for field crop and vegetable growers interested in organic agriculture.
Success with a SARE farmer grant: The science of fighting flies
Jason Peterson
University of Illinois
Lisa Haynes, a nuclear engineer by training, has made something of a science out of controlling onion flies. In 2005, Lisa and Eric Haynes of Mahomet, Illinois, received a SARE grant to look into methods of controlling an onion fly infestation, which was damaging anywhere between 10 to 50 percent of her onion crops yearly on their 17-acre farm.
“The onion fly maggots will just bore into the onion and either kill it or damage it,” says Lisa Haynes, who became attracted to organic farming as a nuclear engineering graduate student while working on the Blue Moon farm in Urbana. Lisa does most of the hands-on work on the farm, while her husband Eric tends to the mechanical needs in addition to his off-farm job.
With the SARE grant support, Haynes tried out the three most promising organic methods for controlling the flies—parasitic nematodes, ground organic cinnamon and kaolin clay. Currently, she has found the parasitic nematodes to be the most useful method to control the onion fly problem. After applying the nematodes, about 15 percent of her crop was damaged in 2007, but only 2 percent was severely injured. Severe damage is defined as damage that impacts marketing.
She sprays her crops with parasitic nematodes just as the onion fly eggs reach the hatching stage. The nematodes then bore into the eggs and kill the larvae. Typically, there are three generations of onion flies in a year, and she says you have to hit each generation.While the nematodes target the pests in the maggot stage, the other two methods—cinnamon and clay—target them in the fly stage. Haynes applied the cinnamon as an olfactory disruptor. In other words, it masked the scent of the onions, so the flies would not be attracted to the crops. The main drawback to this method was efficiency. Haynes tried to mix the cinnamon into a suspension so she could spray it on the crops, but it just dispersed and floated on the top. It also took longer to clean out the sprayers after every application than it actually took to spray the crops. In the end, she found that the easiest way to apply cinnamon on the crops was by sprinkling it.
The clay, meanwhile, was effective because the onion flies do not like landing on the abrasive surface created by the clay and stay away from the crops when they are covered in it. The clay also tastes bad to the flies, which consume the clay while trying to clean themselves. The clay had to be washed off of the produce before it was sold at the market. But the drawback was that it would leave behind a white residue on the leaves, which customers might think was mold. But Haynes still likes the idea of using clay on crops like apples and plums, because it washes off easily from them.
A couple of less successful methods that Haynes experimented with were row covers and heritage turkeys. The plastic row covers tore easily and didn’t do a good job covering the leeks and garlic, which reach several feet in height. The turkeys helped control some of the flies; but despite being kept in a moveable coop, many of them were killed by “a particularly nasty predator.”
However, Haynes did have success in combining the parasitic nematodes with one other control method—trap crops. She planted giant onions between the old onion field and the new field with the goal of intercepting the onion flies on their way to the new field. Haynes likes this method because she prefers to spray as little of the crop as possible, even with organic products. “But if I use trap crops again, I would go with elephant garlic, which they go for more than anything. It would be a more effective trap crop than a big, old onion.
Christina DiFonzo
MSU Entomology
Dave Voegtlin at the University of Illinois conducts a soybean aphid over-wintering survey each spring. He visits buckthorn sites in Indiana, Ohio, Michigan and Illinois looking for aphid colonies or signs of infestation on leaves. Here are his findings. Note his Michigan observations relative to aphid numbers and soybean emergence relative to surrounding states.
“Given the low fall flight numbers, I was not expecting to find many aphids and was also wondering how the cool, wet spring might have changed the dynamics. To my surprise, we managed to find some colonies at every major Rhamnus cathartica location that we visited from northeast Indiana to southeast Michigan/Toledo to Moline, Illinois. At most of the locations the colonies were small and uncommon. The highest numbers we observed were northwest of Battle Creek, Michigan near the Kellogg Forest where colonies were easily found and relatively large. Harmonia axyridis were seen only at the site near Kellogg Forest.
At all locations there were alatoid (winged) nymphs present and at the Quad Cities, strongly deformed growing tips with remnant colonies suggests that most of the aphids were on their way to soybeans. However, finding soybeans will clearly be a problem in much of Illinois and Indiana. We saw very few fields of emerged beans and most of last year’s corn fields appeared uncultivated. The exception is Michigan, where it appears that most areas are planted.”
Kate Leitch
MSU Department of Community, Agriculture, Recreation and Resource Studies
June 12 was a wonderful day at the Kellogg Biological Station (KBS); the weather was great, the speakers were fascinating and the cover crops were looking good. We started the day indoors, listening to five talks from professors and Extension educators. PowerPoint presentations from this program are available at http://michiganorganic.anr.msu.edu/. A summary of the workshop is given below and on the main page with links to the presentations.
Anne Verhallen from the Ontario Ministry of Agriculture, Food and Rural Affairs, gave an overview on cover crop attributes in vegetable systems. Her talk was particularly attuned to the audience's interests and there was opportunity for feedback and questions throughout her presentation.
Mathieu Ngouajio, associate professor of horticulture at Michigan State University (MSU), taught us about biofumigant cover crops. We learned about the biochemistry of biofumigants and how this information can help to develop more efficient cover cropping practices.
Darryl Warncke, MSU professor and Extension specialist in the Department of Crop and Soil Sciences, talked about nutrient management using cover crops. He provided a lot of interesting information about the dynamics of nutrient cycling and how understanding those dynamics can help improve nutrient availability.
George Abawi, professor of plant pathology at Cornell University's New York State Agricultural Experiment Station, gave a presentation on the role cover crops play in soil health and root disease management. We learned a lot about a particular soil testing system Dr. Abawi is developing.
Daniel Brainard, assistant professor of horticulture at MSU, spoke about cover crop mixtures for integrated weed and nitrogen management. Throughout his talk he made points about the financial pros and cons of cover cropping.
During the second half of the day we ventured into the KBS fields to examine cover crops from another angle. Sieg Snapp of KBS introduced us to perennial wheat. We got a good look at the wheat's roots, and had discussion about the differences and similarities between perennial and annual wheat (e.g., gluten content). We witnessed a demonstration of a crimper in use; this piece of equipment is useful in killing a cover crop by breaking its stems, yielding a nice, green mulch.
Photos of the meeting are posted at http://michiganorganic.anr.msu.edu/. If you have any questions, please contact Vicki Morrone (sorrone@msu.edu) or Kate Leitch (leitchka@msu.edu).
Indiana
West Central Indiana, Tippecanoe County – Kevin Cooley
The weather for the past two weeks has been favorable. It started out with heavier rains and hot, humid nights, but this past week we’ve had drier weather and cooler nighttime temperatures.
The last two weeks we have been busy weeding and catching up on some earlier missed plantings. We have been picking peas, squash, beets, lettuces, greens, radishes, turnips, raspberries and strawberries. We started green beans today. Last week we got sweet potatoes planted.
During the next two weeks we will start harvesting new potatoes and cucumbers. Field work will include hand weeding the new strawberry patch, setting aside the older strawberry patch, transplanting rhubarb, and digging potatoes. Tunnel work will include preparation for fall tomatoes and cover crops.
South Central Indiana, Brown County – Dale Rhoads
Several weeks ago we had 11 inches of rain over 8 - 10 hours that caused major flooding in some surrounding areas, but did not affect us or nearby farms. We did have minor soil erosion, but that was mostly where vole holes collapsed and made minor “tributaries.” Since then we have had several more hard rains, but again no damage. Currently we are a little dry. I have been doing some watering the past several days on some transplants that are still establishing themselves. We have been having cool nights and this is slowing down the growth of some of the summer crops like basil. We had a pretty mild winter and have some heavier than unusual pest pressures, especially with cabbage looper on kale. Instead of a few flying and dancing over the kale, it sometimes looks like it is snowing. Those are the ones that survived the winter and we are killing the first generation so their numbers should drop soon.
Currently, we are finishing up on our lettuce harvest and in full swing with baby greens, kale, chard, dandelion and green onions. Summer squash is just starting. We are tying up tomatoes, tilling in lettuce areas for summer time baby greens production, pest control on kale and fruit, harvesting sour cherries and still transplanting a little basil.
Over the next two weeks we will be doing much of the same as we are currently doing, transitioning from spring to summer crops.
Illinois
Northern Illinois, Kane County – David Campbell of Lily Lake Organic Farm
The dry weather last week allowed me to finally plant soybeans, as well as harvest first cutting hay. Wet weather is forecasted to return again tomorrow. I will plan to cultivate corn most of the day today, and will also bale a small amount of hay that is still on the ground.
I finished planting soybeans last week and rotary-hoed my beans for the first time last Saturday. I was also able to harvest some first cutting hay without getting rained on last week.
In the next two weeks I hope to finish first cutting hay harvest. I plan to spread fertilizer on my hayfields after all hay has been harvested. Today I will start cultivating corn for the second time. I plan to rotary-hoe my soybeans for the second time around Thursday of this week. Also I will be hand-hoeing thistles out of my oat fields.
Question
What kind of yield response are others getting from applying gypsum to their fields, especially in small grains and hayfields?
West Central Illinois, Fulton County – Anne Patterson of Living Earth Farm
The last rain we had was on June 13, which was 11 days ago. It has been very windy most days, forming a hard rock crust over much of the growing beds. However, finally we have been able to move freely into all areas of the three acres. I have an urgent sense to get weeds under control. Way too much labor is being spent on this task.
Current farming practices include:
- Twice a week harvesting for e-customers along with one midweek Farmer’s Market.
- Weeding and mulching.
- Planting transplants for fall cabbage and kohlrabi. Direct seeding of third crop of beets and carrots. I finally planted the last of my sweet potato slips this past week and the last of the cantaloupe transplants and remaining brussel sprouts.
- Tied up tomatoes using the Florida weave system.
- Planted buckwheat in spent beds.
- Mow weeds and clean potato beds that have been neglected.
- Continue to heavily mulch in summer crops such as peppers, eggplant and cucumbers.
- Do the second planting of cilantro and continual planting of lettuces.
- Transplant leeks. I know this is really late. I will probably have to overwinter these under straw for next season.
- Plant third and last crop of bush green beans.
- Harvest snow peas, along with other crops such as broccoli, cherries, herbs, cabbage, etc. for market and e-customers.
What success have farmers had planting mammoth clover in the summer versus spring?
Michigan
East Michigan, Arenac County – Ivan Morley
Since our last conference call we have had several rains; none were real bad, but made hay making and cultivating nearly impossible. I have cultivated all of my corn and soybeans once and started cultivating my corn for a second time yesterday (June 23). I may plant some dry beans yet.
Question
I am wondering about insect problems from the wet weather.
Information about permission to reprint or post our articles. Funding to initiate this network was provided by the American Farmland Trust and EPA Region 5. Web site hosted by the MSU IPM Program. Contact webmaster. |
 |