Maximizing Log Based Shiitake Mushroom Production by Determining Optimal Fruiting Conditions

Maximizing Log Based Shiitake Mushroom Production by Determining Optimal Fruiting Conditions

Summary

Nicholas Laskovski, owner/founder of Dana Forest Farm and Bridgett Jamison, Graduate Student at UVM have collaborated to perform on-farm research at Dana Forest Farm in Waitsfield, VT. The research goal will seek to provide optimal fruiting times and conditions for the production of log-based shiitake mushroom cultivation.

In the first year (2011), our research tested several methods for determining mycelial colonization and
moisture levels within inoculated shiitake logs (aka bolts). In 2012, we continued our colonization research as well as created time trials for full water immersion of logs (aka shocking) to ‘force fruit’ shiitake from incoulated logs. By trying to understand exact length of time for shocking (0 hours, 6 hours, 12 hours, 24 hours, 48 hours) farmers will
be better able to manage their shiitake laying yards and optimize timing for efficient production and market availability.

In 2013, additional research trials were attempted, however fruting results were compromised by deer.  This is the first time that deer have posed any problem with regard to shiitake production at Dana Forest Farm.  The solution to protect against deer for future trails is relatively simple, however due to the relative nature of shiitake production, our experiment required an extra year of duration in order to complete one or two more ‘shocking’ trails in the summer of 2014.  The Game Warden provided us with a “Critter Gitter” motion activated noise maker and we talked about surrounding the laying yard with movable/temporary fencing.  Frutiing blankets or shade netting can also be draped over the logs during fruiting.  These are all fairly low cost solutions to hinder deer from accessing the logs and will be used in combinaton next fruting season.

Ultimately, our goal is to determine conditions which will allow for increasing shiitake yields. By increasing yield, our research will allow current log based shiitake farmers to save time and money while increasing farm revenue. New
or upcoming shiitake farmers could justify adding or increasing log-based shiitake cultivation to their current farm or forests, ultimately diversifying operations, creating a more sustainable economic future for farmers of the Northeast.

Objectives/Performance Targets

In the spring of 2011, I felled thirty sugar maple trees. Trees were cut into three-foot lengths generating 500 three-foot long logs with a diameter between 4 and 6 inches. The bolts were inoculated on either 4/17/11 or 5/1/11 following standard procedures. Out of these 500 inoculated logs, 100 logs were randomly selected for the detailed experiment.

Each log was labeled using a durable metal aluminum tag. Initial log weight, diameter, and length were recorded. 2011 sampling dates and summary are provided in the 2011 Annual Summary. We sampled these logs again on May 20th and August 11th, 2012. During sampling, we recorded log weight.

Time trails for shocking began at 12:00 on September 1st, 2012 (48 Hour Shock). Subsequent shockings occured at; 12:00 September 2nd (24 Hour Shock), 23:59 September 2nd (12 Hour Shock), 06:00 September 3rd (6 Hour Shock), and 12:00 September 3rd (0 Hour Shock). All logs were removed from our pond between 12:00-12:15 on September 3rd and placed in fruiting stacks under the same shaded conditions. Because of colonization and timing, we were only able to provide one shocking treatment for our experimental logs. Results are provided in the attached graph in the 2012 annual report. It is known that Year 2 and Year 3 produce higher volumes of shiitake than year 1. Post inoculation, the same logs are able to bear shiitake mushrooms for up to 5 years with repeated shockings – usually 2 shockings per year. (I have personally seen logs fruit shiitake mushrooms up to 10 years after inoculation).

In 2013, we repeated our time trail shocking experiment on September 13th, 2013.  The first trial (24 Hour Shock) was begun at 18:00 on September 13th.  Using the same timing durations as in 2012, all logs were removed between 18:00-18:15 on September 15th.  The results from fruiting from the shocking trial were compromised due to deer harvesting almost 100% of fruting mushrooms before they were ready for harvest. See attached photos.

• Fruiting shiitake logs, same stage, no deer damage.
• Fruiting shiitake logs post deer damage.
• Frutiing research shiitake logs post deer damage.

Accomplishments/Milestones

In 2012 and 2013, we attempted to determine the relationship between shocking duration and mushroom yield.  We shocked 100 logs for five different lengths of time (dunking, 6 hour, 12 hour, 24 hour and 48 hour) and arranged the logs in preparation for fruiting.  In 2013, were unable to collect the results; deer ate all of the fruiting bodies.  These additional trials were meant to increase the validity of results from 2012.

In addition, we also performed the Bromophenol Blue color test on the 100 log “cookies” collected during spring of 2012.   The dye clearly discolored the areas of the log that had not been affected by shiitake mycelium blue. Each colored log cookie was carefully photographed allowing us to determine the degree of colonization. 

The area of “blue wood” and “yellow wood” was measured using advanced imaging software and the exact degree of mycelium colonization was determined. We then plotted the degree of colonization (measure using digital image analysis) against and first year log yields and log density.

• Correlation between Percent Fungal Colonization (DIA) and Log Density
• Correlation between fungal colonization estimated using BPD DIA (%) and shiitake production (kg)
• Example showing fungal colonization based on BMP application

Impacts and Contributions/Outcomes

Our tribulations with the deer taught a valuable lesson.  Deer can seriously damage shitiake crops and logs may need to be covered during fruiting to prevent future damage. 

Becuase the deer consumed the mushroom prior to harvest, we were not able to gather any additional meaningful information regarding this impact of soaking duration on shiitake yields.  In addition, we were unable to run futher analysis comparing BMP color change within logs to yield.  Additional trials will be conducted next summer and the lack of results required us to apply for a non-monetary extension.

Immediately after deer damage occured, the Washington County Game Warden was notified and methods were discussed to mitigate future damage during next season’s shiitake growing period.  The Game Warden provided us with a “Critter Gitter” motion activated noise maker and we talked about surrounding the laying yard with movable/temporary fencing.  Frutiing blankets or shade netting can also be draped over the logs during fruiting.  These are all fairly low cost solutions to hinder deer from accessing the logs and will be used in combinaton next fruting season.  The time commitment is also minimal which is an important factor within our study and the overall production and management of log grown shiitake.

Collaborators: