Progress 10/01/05 to 09/30/11
Outputs
OUTPUTS: Printed materials, presentations at grower and scientific meetings, and field days were used to disseminate outcomes. We made presentations on weed management in vegetable crops at two Extension meetings for a total of approximately 100 farmers. Eight farmers participated in our on-farm evaluation of cover crops to improve the current weedy fallows often used on sustainable and organic vegetable farms. A survey and case study served as a tool to receive feedback from approximately 250 farmers (surveys) and six farmers (case studies). This information will allow us to better target our educational activities aimed at organic growers. We developed a book for farmers on research we and others conducted for fruit and vegetable farmers. A total of fifty copies were distributed. A scientific audience was addressed through presentations at both the Weed Science Society of America and the American Society for Horticultural Science. A total of seven presentations were made to a total audience of one hundred scientists. A publication was also accepted for Weed Science. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Our target audience were farmers and scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We focused on developing replacements for atrazine herbicide and providing the latest information to sustainable and organic farmers on weed management. Atrazine is the most widely used herbicide in sweet corn and yet it has environmental and health concerns that necessitate development of replacements or methods to lower atrazine application rates. The atrazine replacement study focused on using linuron alone or in combination with low rates of atrazine, halosulfuron, mesotrione, or nicosulfuron. Halosulfron, mesotrione, and nicosulfuron are used at low rates nand are environmentally safe but must be combined with atrazine. Linuron alone, combined with reduced amounts of atrazine or with halosulfuron, mesotrione, or nicosulfuron did not injure the sweet corn and provided weed control similar to atrazine. This suggests that atrazine use could be reduced although at the present time the cost of alternative herbicides could require increases in sweet corn costs to the consumer. A second study worked with sustainable farmers to incorporate cover crops in their current fallow instead of allowing weeds to grow. The on-farm study found that fall (cereal rye, winter wheat, or hairy vetch) and summer cover crops (i.e. sudangrass, buckwheat) were effective methods to replace weedy fallow on sustainable farms. The cover crops are inexpensive, reduce weed growth, and improve the soil compared to weedy fallow. These benefit the following crop (usually vegetable crops), reducing weed control costs and improving crop yield. The third study used survey and case study approaches to determine how an organic farmer gets information about and decides the approaches to use for weed management. Variables included what a farm produces, farmer education, years farming, and information source. Three different approaches, those who had a negative perspective of weeds, those who had a positive perspective of weeds, and farmers who were tolerant of weeds, were identified. The farmers trusted other farmers and field days the most for weed management information. The research findings will allow educators to target outreach in a manner that improves adoption of information and improved technologies. The consumer will benefit from increased availability and lower costs for sustainable and organic vegetables.
Publications
- DeDecker, J. and Masiunas, J. 2010. Social factors influence midwestern organic farmers adoption of weed management practices. Abstracts of the Annual Meeting American Society for Horticultural Science.
- Masiunas, J.D., Anderson, J., DeDecker, M., Williams, J., Pataky, J. and Riechers, D. 2010. Sweet corn response to Linuron. Abstracts of the Annual Meeting American Society for Horticultural Science.
- Masiunas, J., Anderson, D., Sun, L. and Zhu, X. 2011 Can Linuron replace Atrazine in sweet corn Abstracts of the Annual Meeting Weed Science Society of America.
- Naylor, D. and Masiunas, J. 2010. Transactions of the Illinois Horticulture Society and the 13th Annual Illlinois Fruit and Vegetable Research Report. Illinois Horticulture Society, Bloomington, IL.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Fact sheets were developed on identifying and managing Canada thistle (Cirsium arvense) and quackgrass (Agropyron repens). These, along with additional resources were posted on the University of Illinois organic agriculture website. With our three-member farmer advisory team, a mini-grant program was developed. We evaluated sudangrass cover crops to suppress Canada thistle in twelve on-farm trails in northern Illinois and southern Wisconsin. The trials allowed organic farmers to modify the system and adapt sudangrass to fit their cropping systems. I made an invited co-presentation (with Adam Davis) titled Strategies for Managing the Weed Seedbank at the 21st Organic Farming Conference, La Crosse, WI. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Perennial weeds are especially challenging for sustainable and organic farmers who are unable or unwilling to use synthetic herbicides. Recent research has identified techniques that hold promise in helping farmers with this problem. Our objectives were to increase farmer knowledge of when to control perennial weeds and what are the most efficacious strategies. The farmers found that sudangrass planted before June 15 suppressed Canada thistle for two growing seasons. In a second study we evaluated weed management strategies on growth and yield of 30 hot pepper cultivars. Black mulch combined with between row tillage (3 times) and hand-hoeing controlled (>90%) weeds. C. frutescens cultivars took longer to mature and yielded less than cultivars of other hot pepper species irrelevant of weed management strategy.
Publications
- Samtani, J., Masiunas, J.B. and Appleby, J. 2010. White oak and northern red oak leaf injury from exposure to chloroacetanilide herbicides. HortScience 45:696-700.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: There were several different outputs including presentations at farmer meetings, published research reports, on-farm research, field days, presentations at scientific meetings, and a scientific publication. Presentations on pumpkin weed control and management of perennial Canada thistle were made at the Illinois Specialty Growers Conference, the Midwest Organic Growers Conference, and the IL and WI Fruit and Vegetable Growers Meeting. The Transactions of the Illinois Horticulture Society and Illinois Fruit and Vegetable Crops Research Report was published with articles on sudangrass suppression of Canada thistle and the evaluation of new environmentally-friendly herbicides for pigweed and waterhemp management in pumpkins and snap beans. An on-farm research network was initiated to foster farmer adoption of reduced herbicide systems to manage Canada thistle. Fifteen farmers participated in the on-farm research network. We participated in both the Agronomy Day field day (presenting the herbicide work with pumpkins and the on-farm research network) and a Pumpkin Field Day (presenting herbicide evaluation for pumpkins). Approximately 400 farmers participated in the field days. There was substantial interest in methods to control problem weeds in pumpkin. Presentations on sudangrass cover crops to suppress Canada thistle were made to scientists at both the American Society for Horticultural Science and the annual meeting of the Weed Science Society of America. We also published a paper on using sudangrass and mowing to control Canada thistle in a journal for scientists involved in applied weed science. PARTICIPANTS: Our project involved fifteen farmers primarily located in northern Illinois. These individuals had an opportunity to evaluate the sudangrass cover crop system for managing Canada thistle. They identified that sudangrass had to be planted before mid-June to successful suppress Canada thistle. TARGET AUDIENCES: Our project has several target audiences. A major target audience is organic and sustainable farmers having problems controlling Canada thistle. A second audience is vegetable growers unable to manage purslane, nightshade, or pigweed and waterhemp in Cucurbitaceae. Our efforts also are designed to cause a change in knowledge of Extension educators, farm advisors, and scientists. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Several challenges in weed management face organic and vegetable farmers. Canada thistle is a perennial spreading weed that is difficult to control in farming systems with reduced reliance upon herbicides for weed management. Experiments were conducted in Champaign, Illinois to evaluate the combined effects of summer annual cover crops and mowing on Canada thistle growth and survival. Sudangrass mixed with cowpea or sudangrass alone produced more standing biomass, greater regrowth, and more surface mulch following mowing than the buckwheat. A single season with sudangrass or sudangrass mixed with cowpea reduced Canada thistle shoot density and mass to less than 20% of the initial values through two growing seasons. Mowing alone only suppressed Canada thistle shoot density and mass on the site with greater initial density. A sudangrass or MIX cover crop alone or combined with mowing suppresses Canada thistle but intensive management must continue several years to eliminate patches. Weed management in Cucurbitaceae crops (pumpkin, squash, cucumbers, and melons) is difficult because the crops are low growing, may not close canopy, are relatively noncompetitive, the vining habit does not allow tillage or hoeing, and registered herbicides do not control all problem weeds. S-metolachlor and fomesafen (at 0.56 kg/ha) caused more pumpkin injury than any other treatment. Using a lower rate of fomesafen (0.28 kg/ha) with clomazone and ethalfluralin or s-metolachlor did not cause more injury than either herbicide alone. The post-directed treatments with either carfentrazone or fomesafen and the s-metolachlor and fomesafen (at 0.56 kg/ha) preemergent treatment provided 90% or greater weed control. The combinations with fomesafen controlled common purslane, a new problem weed in Cucurbitaceae crops. Combinations of either clomazone + ethalfluralin or s-metolachlor followed by a post-direct application of carfentrazone provided season-long control of nightshade and ALS-resistant waterhemp species. These herbicide combinations will improve the sustainability of Cucurbitaceae cropping systems.
Publications
- Bicksler, A.J. and Masiunas, J.B. 2009. Canada thistle (Cirsium arvense) suppression with buckwheat or sudangrass and mowing. Weed Technology 23:556-563.
- Bicksler, A. and Masiunas, J.B. 2009. Mechanisms explaining sudangrass interference and defoliation suppression of Canada thistle. Annual Meeting of the American Society for Horticultural Sciences (http://ashs.confex.com/ashs/2009/webprogram/Paper2096.html).
- Masiunas, J., Gehrig, J., Rak, K. and Bicksler, A.J. 2009. Evaluation of herbicide combinations for pumpkins. Transactions of the Illinois State Horticultural Society and the 12th Annual Illinois Fruit and Vegetable Research Report. Pp. 80-88.
- Masiunas, J., Gehrig, J., Rak, K. and Bicksler, A.J. 2009. Evaluation of herbicide combinations for snap beans. Transactions of the Illinois State Horticultural Society and the 12th Annual Illinois Fruit and Vegetable Research Report. Pp. 89-94.
- Bicksler, A.J. and Masiunas, J.B. 2009. Canada thistle management with summer annual cover crops and mowing. Transactions of the Illinois State Horticultural Society and the 12th Annual Illinois Fruit and Vegetable Research Report. Pp. 95-96.
- Masiunas, J. and Anderson, D. 2009. Best sustainable management practices for perennial weeds. Transactions of the Illinois State Horticultural Society and the 12th Annual Illinois Fruit and Vegetable Research Report. Pp. 95-96.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Canada thistle is becoming a major problem in the midwestern U.S. Presentations on the use of sudangrass to suppress Canada thistle were made to organic farmers (Midwest Organic Production and Specialty Marketing Conference; Upper Midwest Organic Farming Conference), fruit and vegetable growers (Illinois Specialty Growers Conference), and conventional corn and soybean farms (University of Illinois Agronomy Day). Our recommendations on the use of sudangrass cover crops and mowing to control Canada thistle was developed into a Fact Sheet which was given to approximately 200 farmers at summer field days. A web page on Canada thistle was created on the university of Illinois Agroecology and Sustainable Agriculture web site. This web page included summaries on control methods for Canada thistle, our Fact Sheet, and links to web-based resources on Canada thistle. We established an on-farm research network with four farmers that had Canada thistle problems. They evaluated sudangrass cover crops on their farms. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our research developed a sudangrass cover crop system that provides an important new tool for farmers to suppress Canada thistle. Sudangrass or a mixture of sudangrass and cowpea reduced the number of Canada thistle's shoots 3, 12, and 15 months and biomass 12 months after planting the cover crops compared to in fallow or buckwheat. Mowing either once or twice did not consistently control Canada thistle, but may be beneficial when used with a sudangrass or a sudangrass - cowpea cover crop. The sudangrass produced more shoot weight then buckwheat and had greater regrowth and surface mulch production following mowing. Sudangrass regrows after mowing, produces a weed suppressing mulch, leaches allelopathic chemicals from its root system and mowed biomass, and can out-compete Canada thistle. Overall, a sudangrass or a sudangrass - cowpea cover crop combined with mowing offers potential for reducing survival of Canada thistle in farming systems. Studies examined the mechanisms causing defoliation and sudangrass cover crop to control Canada thistle. Multiple defoliations reduced thistle shoot and root biomass, number of shoots, and height compared to no defoliation. In a second experiment, sudangrass competition, defoliation, and surface mulch reduced thistle shoot and root biomass and number. Sudangrass competition reduced thistle fitness more then defoliation. The third experiment separated the effects of sudangrass allelopathy from competition on thistle fitness. Sudangrass allelopathy did not reduce thistle fitness. Sudangrass cover crop reduced thistle biomass through competition for light. The sudangrass surface mulch modified the soil surface environment. Defoliation reduced thistle leaf surface available for photosynthesis and can work in conjunction with light competition to reduce Canada thistle fitness. Canada thistle root biomass increases with increased thistle shoot biomass and number. Thistle shoot biomass and numbers can serve as a proxy for root mass to quantify the effectiveness of control strategies.
Publications
- Masiunas, J.B. and Bicksler, A. 2008. Summer annual cover crops for Canada thistle management. Weed Science Society of America Abstracts 49:259.
- Masiunas, J.B. and Bicksler, A. 2007. Suppression of Canada thistle in organic cropping systems with Sudangrass. Weed Science Society of America Abstracts 48:201 (http://www.abstractsonline.com/viewer/viewSession.asp).
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Progress 01/01/07 to 12/31/07
Outputs
Canada thistle (Cirsium arvense) is a vigorous, creeping perennial weed that forms dense patches. There are few options to manage Canada thistle in organic cropping systems. Tillage creates propagules from the deep, fibrous root system, further spreading the problem and causing larger patches. It can take many years of intensive mowing to suppress thistle. Warm season annual cover crops grow when Canada thistle root reserves and ability to regenerate are low and when seedlings first emerge. Competitive summer annual cover crops may prevent thistle growth, flowering and seedling establishment. In preliminary research, Sudangrass reduced Canada thistle while cowpeas alone did not. Combining Sudangrass and cowpea may reduce thistle populations while supplying legume-derived nitrogen for subsequent crops. In 2006, field studies were conducted on organic farms and the University of Illinois Cruse Research Farm using established patches of Canada thistle. Prior to planting
cover crops, we tilled to kill emerged thistle, slice the upper roots into small pieces, and prepare the seedbed for planting cover crops. The cover crop treatments were no cover crop (weedy fallow), buckwheat, Sudangrass, and Sudangrass + cowpea. The cover crop treatments were mowed either none, once or twice. Cowpea could not compete with Sudangrass and most cover crop plants in the mix were Sudangrass. Even without treatment, the number of Canada thistle shoots decline over the growing season. This decline in number of shoots in a patch of Canada thistle is natural and is likely due to failed establishment, competition between thistle plants, and pest attack. Cover crops and mowing acted independently to reduce thistle patches. At 3 months after planting cover crops, thistle was 21 and 3% of initial numbers in the buckwheat and Sudangrass (alone or with cowpea), respectively. At 3 months, mowing once reduced thistle more than mowing twice. Two mowings further damaged growing points
of thistle but made other weeds and cover crops less competitive and triggered emergence of new thistle shoots. In 2007, at the Cruse Research Farm we determined if previous year treatments affected Canada thistle patches. The field was intensely tilled and we planted organic food-grade soybeans. In soybeans, the areas formerly with Sudangrass or Sudangrass + cowpea had Canada thistle populations approximately 2% of those the previous spring. Canada thistle shoots emerging in these areas were stunted and not competitive with the soybeans. Areas mown once had fewer thistle shoots than areas mown twice. Mowing and buckwheat only suppressed thistle for a single growing season. Sudangrass rapidly grows, tills extensively, forms a tall dense canopy, tolerates mowing, quickly regrows, and forms thick mulch.
Impacts
We found that Sudangrass combined with mowing controls Canada thistle due to competition for resources and leaching of allelopathic compounds from roots. Mowing also defoliates thistle (mown at 7-10 leaf stage) and causes Sudangrass re-growth and tillering resulting in more competition for light. The thick mulch can smother thistles, modify the soil environment (cooler temps, increased moisture), and release allelochemicals. Our research allows fruit, vegetable, sustainable and organic farmers to manage a severe problem weed while improving the soil and avoiding use of nonselective herbicides.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
We evaluated buckwheat and Sudangrass alone or combined with mowing for their suppression of Canada thistle. Canada thistle plant densities decreased by 31% in the no cover crop, no mowing treatment. Mowing alone further reduced thistle density and shoot biomass. Buckwheat was very competitive with Canada thistle reducing the number of shoots by 92% and their shoot weight to 21% of the fallow. Mowing reduced the effectiveness of buckwheat in lowering the thistle density probably because buckwheat did not regrow after mowing. Sudangrass without mowing reduced number of thistle plants by 98% but adding mowing provided a further reduction in thistle shoot weights. Sudangrass provides an option for organic farmers to suppress Canada thistle but complete control of Canada thistle will require a multiyear program integrating a variety of management strategies followed by continual monitoring to prevent the establishment of new populations.
Impacts
Summer annual cover crops such as buckwheat and Sudangrass provide farmers with a readily-usuable alternative to herbicides for controlling problem perennial weeds such as Canada thistle. By providing an alternative to nonselective postemergence herbicides, our research will reduce pesticide use and protect the soil. Buckwheat and Sudangrass have extensive root systems and will improve soil quality. Perennial weeds are more likely to be a problem for farmers trying to increase their operation's sustainability by reducing or eliminating herbicides, shifting tillage practices, and integrating cover crops into their systems. Thus, our research will increase the sustainability of food cropping systems. It will help meet consumer demands for sustainable and organic foods.
Publications
- Garces Ortega, M.N. 2006. Seed bank dynamics in alternative vegetable cropping systems. M.S. Thesis. Universty of Illinois at Urbana - Champaign.
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