Organic vegetable production weed control strategies: Integrating precision cultivation,weed biology and OMRI herbicides

Organic vegetable production weed control strategies: Integrating precision cultivation,weed biology and OMRI herbicides

Summary

Small-scale organic farmers are challenged by weeds in their efforts to produce vegetable crops profitably. Some vegetable crops are successfully produced utilizing plastic mulch as a weed barrier. Other crops such as broccoli and sweet corn, in instances, are produced without plastic barriers or other mulches. Plastic mulches have issues associated with use and disposal. Organic vegetable crop producers also rely on non-selective natural product herbicides requiring multiple precision applications to small weeds. Mechanical cultivation by hand hoeing or tractor mounted cultivation is another approach utilizing experienced labor. Cover crops and organic mulch are also utilized. Successful weed control programs require farmers have extensive knowledge on all aspects of weed management including weed biology, precision cultivation and herbicide application. This project expands upon previous SARE projects utilizing video, PowerPoint and print addressing cultivation and precision herbicide application. The project proposes a “hands-on” training program for agricultural educators. Interaction between participants will enhance program content including farmer input. Vegetable crops will be established with different growth characteristics such as squash, sweet corn, snap beans and leafy greens. A one-day hands-on training program will incorporate precision cultivating techniques, mulches and application of OMRI herbicides utilizing specially designed sprayers enhancing precision application. Pre-plant weed management programs will be demonstrated including the following: plots addressing weed biology including weed seed dormancy/germination, interaction of cultivation and weed seed germination and perennial weed management.

Objectives/Performance Targets

142 farmers become engaged in a systems approach to weed control in organic vegetable production. Farmers incorporate several technologies in unison addressing the complex issue of weed control. Stale seedbed, precision cultivation, suicide germination of weed seeds, and precision application of organic weed control agents provide enhanced sustainability and profitability.

1] Core group of agricultural educators representing several organizations including Cooperative Extension, NRCS, NOFA and Departments of Agriculture participate in a preliminary planning meeting assessing scope and methodology of a hands-on training program they will be attending at a future date.

Project leader, team members and key individuals query participants for program development. Participants become engaged in project (3 months).

2] Project leader, team members and key individuals along with the core group of participants recruit 50 agricultural educators to attend New Jersey or Delaware training program.

Simultaneously training program logistics and content are being developed (4 months).

3] 25 participants attend first training program. Participants are assessed through a questionnaire survey on their baseline knowledge and educational abilities related to integrated approaches to controlling weeds in organic vegetable production systems. The participants become engaged in hands-on training.

The participants are assessed through the questionnaire survey on their post program knowledge and willingness to engage farmers in educational outreach programs. 17 participants through survey results express willingness to develop farmer training programs impacting 75 farmers. 21 participants through survey results altered their views on the complexity and need for an integrated approach to organic weed control programs (4 months).

4] 25 participants attend second training program.

Participants are assessed through a questionnaire survey on their baseline knowledge and educational abilities related to integrated approaches to controlling weeds in organic vegetable systems. Program content is altered based upon results of initial program. Participants are assessed through the questionnaire survey on their post program knowledge and willingness to engage farmers in educational outreach programs. 23 participants through survey results altered their views on the complexity and need for an integrated approach to organic weed control programs (4 months).

5] A core group of 38 participants utilizing an integrated approach to educating farmers on weed control programs for organic vegetable production.

A group of 77 farmers are trained and surveyed by program participants (9 months). 6] core group of 50 participants are engaged by project leader through follow up contacts requesting additional feedback and survey documentation. 28 participants respond through survey providing additional 75 farmers trained and surveyed. Farmers’ survey results indicate 65 farmers have developed more effective weed control strategies resulting in improved crop production and profitability (12 months).

Accomplishments/Milestones

The project was initiated in the second half of 2009. A preliminary planning meeting was held with lead coordinators from New Jersey, Delaware and Maryland. The participants focused on development of training plots in 2009 in preparation for the professional development training program offered in 2010. Controlling weeds in organic vegetable cropping systems requires a systems approach, the initiation of programs to demonstrate reducing weed competition in 2009 are listed below.

1] Mulching comparisons 2009 – put out mulching comparisons on a piece of land that is prepped for planting. Compare to rates of rye straw that is clean with some dirty mulch hay and possibly add black plastic. It would be a single row maybe 5 feet or 10 feet wide. Take photo of strips in early August 2009. In 2010 allow the mulch plots from 2009 to stay there for viewing by class. In addition put the same treatments in a new row next to the 2009 plots comparing side-by-side. 2] Seedbank effects (treatments to reduce weed populations in 2010 vegetable/sweet corn production) 2009 – Establish three basic plots side-by-side (organic sweet corn production) [reliance on tillage]; soil prep then weed free full-season; every 2 to 3 weeks light tillage to stimulate germination and kill existing weeds. The tillage plot will be kept mostly weed free with constant tillage throughout the year. The other plot will have a stale seedbed approach with tillage and seedbed preparation in 2009 followed by flaming or paraquat. The third plot will be an organic weed control in sweet corn using rotary hoe and 2 to 3 cultivations. Fall of 2009 – cover cropping half of the area of all three areas (planting rye). **Also note we might include a clear plastic subplot to solarize soil. 3] Cover crop evaluation 2009 – Early fall begin planting various cover crops for comparisons: Examples include: Oats (winter kill) Forage radish (winter kill) Cereal rye Barley Ryegrass Cereal rye + vetch In addition discussed looking at two planting dates in the fall and two termination dates in the spring to demonstrate biomass accumulation with rye: Planting Termination Sept 15 May 1 Nov 1 May 30 4] Begin to accumulate herbicides that would be permitted in organic crop production both in the crop if there are any available and preplant materials. At our training session we will definitely discuss EPA guidelines including pesticide applicator licenses etc. regarding organic vegetable weed control practices. Corn gluten GreenMatch (limonene) Matran (clove oil) BurnOut (clove oil and sodium lauryl sulfate) Nature’s Avenger (citrus oil) Natura Weed-A-Tak (citric acid) **note some may need a wetting agent (yucca oil or Nu Film P) 5] Discuss a roller/crimper rye in the spring, accumulating the Rodale video discussing this approach Websites: http://newfarm.rodaleinstitute.org/depts/notill/roller_gallery/ http://www.covercrops.msu.edu/crimper/about.html Video: http://www.youtube.com/watch?v=PW4mwVJPS9A 6] Assemble and experiment with various cultivators 2009 – Assemble various cultivators including a rotary hoe, tine weeder, vegetable cultivator, driving cultivator, detasseling machine, bezzerides, flamer, etc. Experiment with these cultivators, comparing crop injury and frequency of cultivation. 7] Try the stale-seed bed approach of prepping the field, simulate germination and then kill emerging seedlings followed by transplanting with minimal soil disturbance.

On November 17, 2009 a planning meeting was held for the project that included project participants as well as project consultants representing various organizations. The attendees, the affiliations and the summary of the planning meeting are noted below: Northeast-SARE meeting November 17, 2009 Planning meeting – Weed Control in Organic Vegetable Production Attendees and affiliation: C. Edward Beste, University of Maryland; Bradley Majek, Rutgers University; Mark VanGessel, University of Delaware; Edwin Dager, Rutgers University; Erich V. Bremer, State of New Jersey Department of Agriculture; Joseph R. Heckman, Rutgers University; David Glenn, Northeast Organic Farming Association; Jen Reich, Foodshed Alliance; Jerry Lyness, Spring Run Farm; David Zaback, Gravity Hill Farm; Mike Rassweiler, North Slope Farm, John Grande, Rutgers University Summary of planning meeting: 1] It was discussed and agreed to by attendees the training program should stress from the beginning the importance of developing a weed control strategy in the overall farm plan. Erich Bremer, from the New Jersey Department of Agriculture Organic Certification Program included the following summary which will be an excellent guideline for development of weed control strategies. 2] There was considerable discussion regarding the size of organic vegetable farming operations and was pointed out the average New Jersey organic farms is approximately 10 acres. With this in mind discussions regarding cultivating equipment debated the interest in mechanized cultivating including tractor mounted cultivators in comparison to hand tools utilized for weed control. It was decided to increase the emphasis on hand weeding options in the training program including wheel hoes, etc., however, there will still be tractor mounted precision cultivators for training. 3] Regarding weed biology– a conference call was attempted with Chuck Mohler from Cornell University. Chuck explained his weed biology training for farmers and it sounds very interesting and likely to be incorporated into the training program if Chuck agrees. It would take a minimum of 1 1/2 hours. 4] There was a tour of the Rutgers University demonstration plots established in 2009 – noted above. There was significant discussion regarding the use and management of various cover crops as a weed control management tool. An existing winter rye field will be utilized to develop more cover cropping weed suppression strategies for training. For instance a legume over-seeded into rye or sorghum along with mowing. 5] OMRI approved herbicides; several of the better herbicides will be sprayed with backpack sprayers on weeds of varying sizes compared with conventional knockdown herbicides for training audience to view. In addition training to include precision application of these products with backpack and tractor mounted sprayers. 6] There was significant discussion regarding the need to develop surveys of course effectiveness combined with follow-up impact at the farmer level with specific reference to economic issues related to the training. 7] Flame weeding was discussed and the equipment will be acquired for training purposes including backpack flame weeders. Weeds will be flamed in advance of the training- different sizes and species to demonstrate effectiveness of flaming.

• Delaware 2009 plot plan weed impact of mulching programs
• Photos from 2009 weed control project
• Rutgers 2009 organic vegetable weed control plots

Impacts and Contributions/Outcomes

Impacts and Contributions/Outcomes are scheduled to start in 2010.

Collaborators: