Optimizing management of a new invasive species, swede midge, on small-scale organic farms

Optimizing management of a new invasive species, swede midge, on small-scale organic farms

Summary

Swede midge (SM) is an invasive insect pest that is threatening the viability of organic production of Brassica crops in the Northeastern US.  SM is quite small and its damage difficult to identify, so it is commonly misdiagnosed.  For this project, we partnered with six small-scale organic farms to develop effective pest management tools and to conduct outreach/education to familiarize at-risk small-scale organic growers with best management practices to protect them from devastating SM outbreaks.

Intensive monitoring of SM with 59 pheromone traps on 6 farms indicated that crop rotation/separation and selection of tolerant crop types can be effective management strategies for SM, but timing plantings to avoid SM emergence is critical. Insect exclusion netting in combination with various mulches including black plastic, landscape fabric, hay and straw was evaluated in seven small-plot on-farm trials and demonstrations. Results indicated that insect exclusion netting and mulches will protect brassica crops from SM, but its use regarding its effects on plant development and quality, and entire pest complex needs to be optimized.

Educational efforts included presentations at three grower meetings including a workshop at NOFA-NY, which reached 96 growers. Additionally, this project was presented at the Northeast Plant Pests and Soils Conference in Philadelphia, PA and Internationally at the Great Lakes Vegetable Working Group Annual Meeting in London, Ontario, Canada, which reached 70 professionals.  Updates to the SM website to include an organic management section are in progress, as well as plans to develop a fact sheet. 

Tremendous progress has been made during this first year of study towards finding management strategies for SM that can be readily adopted by small-scale organic brassica growers. This project has received a no-cost extension to complete data and economic analysis, develop educational materials and complete report writing.  Additional funding from NESARE has allowed the project to continue through 2016.

Objectives/Performance Targets

This project has received a no-cost extension to August 15, 2017 to complete data analysis and final report writing. The majority of the research was completed as planned by the end of 2015 and included in the 2015 annual report.  For this annual report, we will only comment on progress made in 2016.  Additionally, another NESARE Partnership grant was acquired to continue this project in 2017.

Objective 1.

Advance understanding of swede midge (SM) pressure and invasion on small-scale organic farms growing Brassicas as it relates to management practices.

In 2015, we partnered with six at-risk small-scale brassica organic farms with swede midge (SM) infestations in Allegany (Almond and Alfred Station, NY), Cattaraugus (Allegany, NY), Ontario (Phelps, NY), Schuyler (Hector, NY) and Seneca (Lodi, NY) counties in NY. Farms were selected based on their expressed interest in this project, geographic location and level of SM damage (minor to moderate/severe).  SM populations were monitored on each farm using female sex pheromone traps from early May until mid-November. In total, traps were deployed at 59 sites including in brassica transplant production, at spring emergence (where SM-infested crop occurred previous fall), and in spring, summer and fall brassica plantings.  Traps remained at a site as long as was relevant and male SM trap captures were enumerated weekly.  At harvest, Brassica crops were rated for SM damage. 

In spring 2016, SM trap catch data and SM crop damage was summarized and shared with each of the six individual farms, and recommendations were made for future management of SM.

Objective 2.

Optimize implementation of newly developed disruption tactics including insect exclusion netting and garlic oil repellant to manage SM in Brassicas on small-scale organic farms.

In 2015, insect exclusion netting was evaluated over bare ground and in combination with various mulches including biodegradable black plastic, landscape fabric, hay and straw, for their ability to protect broccoli, Brussels sprouts and kohlrabi from SM. Seven on-farm small-plot trials were conducted with natural SM infestations including three in spring-planted broccoli, one in fall-planted broccoli, one in spring kohlrabi, two in fall kohlrabi and one in Brussels sprouts. 

In 2016, research results were analyzed and summarized for both of the spring and late-summer planted broccoli trials at Muddy Fingers, both of the high and low-risk spring broccoli trials at Quest Produce, and for the fall Brussels sprouts trial at Canticle.  Data analysis and summary of the three kohlrabi trials is planned for 2017, although SM pressure was very low in the fall trial, while the spring trials were adversely affected by harsh growing conditions.

In 2015, weekly applications of 1% solution of essential garlic oil (Bulk Apothecary) were evaluated in three spring-planted broccoli and one kohlrabi small-plot farm demonstrations.

In 2016, trial results were analyzed and summarized for the broccoli trials.  The kohlrabi trial suffered harsh growing conditions.

Economic analysis of insect exclusion netting and mulch as a management strategy for SM is planned for 2017. We plan to follow a protocol for economic analysis that was developed by Elisabeth Hodgedon, a M.Sc. candidate under the direction of Dr. Yolanda Chen.

Objective 3.

Increase awareness of SM and knowledge of its management practices among at-risk small-scale organic Brassica growers.

Statewide Workshop at NOFA-NY:

2016 NOFA-NY Winter Conference. Swede midge: What Brassica growers should know. C.A. Hoepting and C.A. Hall. Saratoga Springs, NY; January 23, 2016 (52 participants).

 Winter Educational Grower Meetings:

2016 Chautauqua Produce Auction Meeting. Swede midge: What Brassica growers should know. C.A. Hoepting. Clymer, NY: March 10, 2016 (25 participants).

 2016 Chautauqua Vegetable School. Swede midge: What Brassica growers should know. C.A. Hoepting. Jamestown, NY: March 17, 2016 (18 participants).

 Professional Conferences/Meetings:

Northeast Plant Pest and Soils Conference (NEPPSC). Prevention of Brassica crop losses from new invasive species swede midge (Contarinia nasturtii) on at-risk small-scale organic farms. C.A. Hoepting and C.A. Hall. Philadelphia. PA: January 6, 2016 (25 participants).

Great Lakes Vegetable Working Group Annual Meeting. Prevention of brassica crop losses from new invasive species, swede midge on at-risk small-scale organic farms.  C.A. Hall.  London, Ontario, Canada: March 2 & 3, 2016 (45 participants). 

Newsletter article:

Hoepting, C.A. 2016.  Do you have swede midge?  New pest of brassicas often misdiagnosed. Featuring swede midge diagnosis in kohlrabi.  Cornell Cooperative Extension Vegetable Program, Veg Edge, 12(22): 3-5.

In 2016, we began work towards developing a new section for the “Swede midge information site for the US” website (http://web.entomology.cornell.edu/shelton/swede-midge/), originally developed by Cornell University, to include organic management.  This is in collaboration with Elisabeth Hodgedon, Ph. D. candidate under direction of Dr. Yolanda Chen, University of Vermont.  It will review all of the strategies that have been tested and failed in order to prevent blind implementation of failed methods as well as the new information and recommendations derived from this project.  Hodgedon is working on sections including intercropping, mating disruption, essential oils and the economics of SM damage and management strategies, while we are summarizing crop type differences, insect exclusion netting, crop rotation and separation, SM monitoring, natural enemies, biological controls, plant resistance and organic insecticides.  Plans include to also develop a fact sheet for organic management of SM in 2017.  In fall 2016, footage was shot to produce a “how to diagnose SM” video, which should be available by the 2017 growing season.

Growers who hosted on-farm trials have also served as resources to other interested growers.

Accomplishments/Milestones

Progres made in 2016:

• Add organic management of SM section to website, “Swede midge information center for US”. Hoepting and Chen. April 2015. Started work in Spring 2016, picked up again in Fall 2016. To be completed in 2017.

• Write and submit “Be on the lookout for SM” article to NOFA newspaper, The Natural Farmer. Hoepting and Chen. April 2015. Another article went out in September 21, 2016 issue of Veg Edge (Cornell Vegetable Program newsletter). Another article will be submitted for greater distribution through Small Farms Quarterly and NOFA in spring 2017.

• Add-on: shot footage for use in “how to diagnose SM” video. October 2016. Successfully executed.

• Collect grower feedback and economic info from growers. Hoepting, technician, growers. November 2015. On-going. Economic analysis scheduled for winter/spring 2017.

• Data entry, analysis and summary. Technician, Hoepting. May-December 2015. In-progress.

• Write and submit annual report. Hoepting. December 2016. Executed successfully.

• Present results at NOFA-NY winter conference. Hoepting. January 2016. Executed successfully.

• Write and distribute project results in newsletter article, update SM website with latest information. Hoepting, Chen. February 2016. In-progress.

• Present results at NOFA-VT winter conference. Chen. February 2016. Did not do.

• Write and submit final report to NESARE. Hoepting.  New deadline: October 15, 2017.

Impacts and Contributions/Outcomes

This project directly led to the following funding sources and is on-going:

• Optimizing management of new invasive species, swede midge on small-scale organic farms; Part II. NESARE Partnership Grant. C.A. Hoepting. $14,999 (2/12/2016 – 4/15/2017).
• Prevention of Brassica crop losses from new invasive species, swede midge on at-risk small-scale organic farms: Part II. Cornell Towards Sustainability Foundation. C.A. Hoepting. $10,000 (1/1/2016 – 12/31/2016).

Research proposal submitted in December 2016:

• Prevention of Brassica crop losses from new invasive species, swede midge on at-risk small-scale organic farms: Part III. Cornell Towards Sustainability Foundation. C.A. Hoepting. $12,000 (1/1/2017 – 12/31/2017). pending

Collaborators: