Asparagus

Michigan Asparagus Industry Research Priorities

Contact person: Jamie Clover Adams (Jamie@michiganasparagus.org)

Top 4 Priorities: (order of listing is not significant)

 

Priority

Lessen the economic impact of soil and foliar disease pests.

  1. Improve control or reduce impacts of soil-borne pathogens such as Fusarium Crown and Root Rot and Phytophthora Crown and Root Rot.
  2. Development of a predictive model for Asparagus Rust.

Estimated Economic Impact:

These two pathogens have combined for estimated yield losses of 25-35 percent of potential yields annually.  Most new asparagus fields are established on ground previously planted to the crop due to the lack of new or “virgin” ground.  Due to residual soil pathogens the yield potential of these fields is 70% of new ground.  Over the life of the field (15 years), these pathogens account for yield losses in excess of 10,000 lbs./acre with a farmgate value of $7000.  Phytophthora root and crown rot was identified in Michigan in the spring of 2004 (Hausbeck, MSU).  Since then, the total yield in the State has dropped from just under 30 million pounds (2003) to just over 20 million pounds (2005) and has remained at that level representing over $5 million in lost revenue (farmgate) each year.

Purple Spot and Asparagus Rust are two significant foliar diseases of asparagus in Michigan.  An effective disease predictive model for Purple Spot has been developed and is widely used in timing fungicide applications.  Climatic conditions favoring the development of Asparagus Rust are different than those of Purple Spot.  The development of a similar predictive model for Asparagus Rust would allow growers to fully implement a cost-effective IPM program for foliar diseases. 

Short or Long Term:

This is a long-term priority.  Industry funds have been used in the past to leverage some outside support.


Priority

Improved marketable yields for both the fresh and processed markets through new or innovative cultural practices such as:

  • Irrigation management
  • Practices promoting healthier crowns or transplants
  • New planting techniques
  • Variety selection for higher tip quality and marketable yields
  • Field preparation strategies for replant fields
  • Nutrient management

Estimated Economic Impact:

The survival of the Michigan asparagus industry is dependent on our ability to improve per acre yields especially on replant ground.  Improved yields will enable Michigan asparagus growers to compete with imports from other countries with significantly lower labor and production costs.  Estimated economic impact is $30 million annually. 

Short or Long Term:

This a long-term priority.  Michigan Asparagus Research Inc. (MARI) funds some cultural practices work annually.


Priority

Develop effective control measures for Asparagus Beetles.

  1. Increase knowledge of pest biology, especially overwintering behavior.
  2. Determine efficacy (possible resistance) of labeled insecticides.
  3. Develop new cultural practices or biological controls that will lessen the impact of this pest, especially during the harvest season.
  4. Develop strategies that will reduce the pesticide applications during the harvest season.

Estimated Economic Impact:

Asparagus Beetles cause damage to asparagus throughout the growing season.  Overwintering adults feed and lay eggs on spears during the harvest season and both adults and larva can defoliate fern during the summer months.  Asparagus beetle eggs on spears are a cause for load rejection if they exceed 2 percent for processing and even lower levels are tolerated for fresh asparagus.  Harvest season insecticide applications are troublesome due to the frequency of harvest, worker re-entry periods and pre-harvest intervals.  Beetle eggs on harvested spears are the number one cause of rejected loads and even field abandonment.  This issue has taken on increased urgency with the recent Chlorpyrifos tolerance revocations by U.S. EPA.  Estimated impact is $5 million annually. 

Short or Long Term:

This is a short-term priority.

 

Priority

Improve storage conditions for fresh asparagus to aid in marketing.

  1. Develop optimal methods to store fresh asparagus
  2. Determine if post-harvest additives or treatments improve storage life of fresh asparagus.

Estimated Economic Impact:

Prices received for fresh asparagus vary greatly during Michigan’s 8-week harvest season and, at times, fall below the cost of production.  Holding (storing) asparagus during these glut periods and then releasing (selling) it when the market improves could have a significant impact on the average returns received by growers.  It is estimated that Michigan growers lost over $3 million dollars in potential revenue in 2019 as a direct result of their inability to store asparagus until prices improved. 

Short or Long Term:

This is a short-term priority

 

Priority

Improve control of herbicide resistant weeds.

  1. Develop control strategies for weeds that are resistant to currently registered herbicides.
  2. Explore traditional and non-traditional methods for controlling weeds in asparagus.

Estimated Economic Impact:

Michigan growers are struggling to control resistant weeds, especially the amaranth sp. in no-till asparagus fields.  Weeds that escape pre-harvest treatments inhibit the harvest operation and directly effect yields.  Weeds that escape treatments made after the last harvest rob moisture and nutrients and have an indirect effect on yields.  It is estimated that combined, yield loss from inadequate weed controls is approximately $2 million annually. 

Short or Long Term:

This is a long-term priority.

 

Updated August 2023