Cultivation of shiitake mushrooms as an agroforestry crop for New England

In the summer of 2010 beginner-level workshops were duplicated at 5 locations (29 participants at Ithaca, NY; 50 at Waitsfield, VT; 26 at Panama, NY; 23 at Greene County, NY; and 20 at Loudon, NH) resulting the training of 148 prospective individuals interested in shiitake cultivation. These beginner workshops covered the basic skills involved in shiitake cultivation (acquiring logs of suitable substrate species, inoculation of logs with mushroom spawn, log colonization; and induction of mushrooms from the logs), be these beginner workshops did not include business enterprise aspects of shiitake sales, etc. Later, during Summer/Fall of 2010 a total of 105 people, who had completed one of the beginner workshops, and who had expressed interest in a commercial scale shiitake enterprise attended either of three advanced workshops (23 attendees at Ithaca, NY; 26 at Panama, NY; and 56 at Waitsfield, VT). These advanced workshops included training in enterprise development, forest management, site assessment, and each also included a visit to one of 3 farms of a commercially successful shiitake farmer (the 3 farmer advisor participants in the project). During the winter of 2011, prospective shiitake farmers who had completed both the beginner and the advanced-level workshop were invited to submit a five year shiitake farming enterprise plan, to be considered for further involvement in the project. During winter of 2011, fifty-four farmers submitted enterprise plans and of these twenty-six farmers were selected for further participation in the implementation phase, which included establishment of a small scale (100 logs) shiitake “enterprise” on their own property. The 26 participants were provided with specific instructions to proceed with log inoculation and other aspects of the implementation phase of the project. A key resource developed for this purposed was “Research Guide for Cultivation of Shiitake Mushrooms”. is available to the public via the NE SARE web page for this project (LNE10-298). Additionally, each of the 26 participants received a “mentoring” visit from one of the project staff during the time they were inoculating logs during Spring 2011.

In addition to the step-by-step instructions for initiating the implementation phase of the project, the Research Guide also provided worksheets for participants to record data over on expenses and income for the remainder of the project. Categories included Labor, Expenses, Fruiting (mushroom yield), Fresh Shiitake Sales, and Value-added Shiitake Sales. These worksheets were also made available to participants as Microsoft Excel spreadsheets.

Twenty three of the original 27 participants chosen for the implementation phase of the project, actually completed inoculation of their 100 logs (85%). Eighteen of the original 23 participants who inoculated logs  successfully produced and sold shiitake mushroom (66%).  Of these who sold mushrooms, 15 participants kept detailed records of the fruiting process and sales (72%).   Reasons given for dropping out of the project were lost access to land (1), death in family (1), unable to purchase bolts (1), began new career (1), bolts lost in flood and broken leg (1), and unknown (4). There appeared to be no consistent reason for dropping out of the project

The compiled results of the data collected from participants are shown in Figures and Tables presented in the 2012 annual project report and attached below. A narrative summary follows below. The breakdown of labor associated with different mushroom cultivation / marketing–related tasks: Initial felling of trees and preparation of bolts in the spring of 2001 took 12% of the total amount of time participants invested in this project from Spring 2011 through Fall 2012.  After felling, the subsequent inoculation of bolts took 41% of their time. Routine laying yard maintenance over the following 18 months took up 10% of their time. Harvest-related activities during the summer / fall of 2012 took 9% for shocking/fruiting, and actual harvesting (picking) took 13%. Sales related activities took 3% for processing, 2% for transporting, 2% for advertising, and 6% for actual sales. The remainder (“other”) took 2% of the total amount of time devoted their shiitake mushroom enterprise through the end of the season in the fall of 2012, but these same 100 logs can be expected to produce mushrooms annually for 2 or 3 more years.  Labor (hours) for individual participants are shown in Table 2. Figure 2 shows that most (71%) of the overall labor (hours) was contributed by the owner (participating farmer) , followed by volunteers/friends (23%), and paid employee (1%).

The expenses and earnings varied widely among participants (Table 2) as described below in the Economic Analysis section of this report. Regression analysis of the data indicated that a participant’s net profit was not significantly influenced by either the amount of labor (Figure 3A) or the amount of money they invested in the project (Figure 3B).    The largest influence on net profit was the annual production cost per bolt; shiitake production per bolt explains 54% of the variation in profits.  Consequently, the next obvious thing to consider is what factors affected production per bolt?

The effect on shiitake mushroom per bolt of several economic and cultural factors were considered including: labor, expense, date shocked, date tree felled, date bolt inoculated, high temperature, and tree species. Linear regression was used to determine the best-fit line and equation and equation for that line, and also the R² value (correlation coefficient).  The probability that the result was statistically significant is indicated by the p-value shown in the figure caption. 

The amount of labor (hours) invested per bolt did have a significant effect on production (p=<.0085, r2=.45) (Figure 4A), whereas the expenses invested per bolt did not have a significant effect on production (Figure 4B). As mentioned earlier, shiitake, unlike other forest cultivated mushroom, can be shocked (force fruited) by soaking bolts in water for 12-24 hours. This has obvious advantages for planning for market delivery on a predetermined schedule. The decision by a given shiitake grower as to when to force bolts is highly individualized with respect to market demand, weather conditions, prior fruiting history, labor availability, etc. The choices a grower makes regarding when to force may have an impact on total mushroom production. The participants in this project force fruited each stack of bolts two or three times during 2012. Figure 5 shows the relationship between the date a given bolt was soaked and mushroom production.  Obviously there is considerable scatter to the data, i.e. not a tight correlation between these two variables (R2 = 0.1) but there is a statistically significant (p=.0001) tendency for later soaking to result in more mushroom production per log.

Another factor that we hypothesized might be a useful predictor of mushroom production is the date on which a living tree was felled (cut down) to produce bolts for inoculation. Conventional wisdom has it that bolts cut from more dormant trees (cut earlier, i.e. late winter, early spring) will yield more mushrooms than bolts cut late spring / summer.  Figure 6 shows that the date of felling the trees did not have a significant effect on mushroom production per log (p=0.3421). This result does not support conventional wisdom, and suggests that growers have greater flexibility in scheduling time for tree cutting although it must be kept in mind that there are many factors in addition to date of felling that differed among growers. In addition to date of tree felling, the actual date of bolt inoculation is a related factor growers must consider. Figure 7 shows that there was a significant tendency (p=.0026) for bolts inoculated earlier in April to produce more mushrooms that bolts inoculated later in the spring.  There was also a significant relationship between the number of days elapsed between felling and inoculation and the pounds of shiitake mushrooms produced (R2= 0.0998; p<0.002).   According to this data, farmers are best served inoculating their log as soon as possible after felling the tree.

Tree species has always been considered an important factor when producing shiitake mushrooms as a forest crop. Conventional wisdom has it that oaks are best, other hardwoods like hop hornbeam (Ostrya virginiana), musclewood (Carpinus betulafolia), sugar maple, and American beech are acceptable, and red maple is a less acceptable substrate for growing shiitake mushrooms. Figure 8 show the effect of several different hardwood tree species on mushroom production per bolt by participants in this project. In this case, there we no clearly superior species among hop hornbeam, red maple, red oak and sugar maple, and red maple did better than expected while American beech did not perform as well as expected.  

In addition to the effect of cultural factors on shiitake mushrooms production, an equally important consideration was how and where they were sold.  Prices obtained ranged from about $12 per pound up to about $16 per pound. Mushrooms sold at farmers markets tended to sell for the highest price, although there was not a great deal of price variation among different venues including direct sales, farmers markets, grocery stores, and restaurants (Figure 9). The proportion of mushroom sold at these different venues was greatest for restaurants (46%), direct sales (19%), farmers markets (15%), groceries (15%), and other (5%) (Figure 10). These results appear in tables and graphs in an appendix to the 2012 annual project report. This kind of systematically collected quantitative data is unprecedented among the literature on shiitake cultivation.

Perhaps the most important accomplishment of this project has been the completion of a 55-page booklet entitled, “Best Management Practices for Log-Based Shiitake Cultivation in the Northeastern United States” (BMP for short).  The BMP differs from other shiitake growers manuals in print and online in two ways. 1) incorporates project-related data contributed by the beginner growers recruited for this project, as described above. 2) The BMP reports not only summarizes what we (PIs, Project Manager and Farmer Advisors) know about shiitake farming from years of experience, which in that respect is similar to other booklets and web sites, but we also solicited advice from experience shiitake growers through the ongoing project-related list serve, in part by incorporating their direct quotes into the BMP. It organizes over one-hundred of quotes and images from 23 people/farms. 3) The BMP also includes results of research on forest cultivation of shiitake and other specialty mushrooms, that was under taken by Mudge, et al. at Cornell’s Arnot Forest, independently from this SARE project. A copy of the BMP manual is attached to the 2013 annual report.

Not all positive outcomes of this (or any) project are necessarily anticipated at the outset (original proposal). In this case the creation and success of this project was a “Mushroom Growers” email listserv (<MUSHROOMS@LIST.UVM.EDU>) was initiated early in the project by Allen Matthews at the Universiity of Vermont. It has proven to be a very effective instrument for experienced growers, beginners and those in between to exchange information about mushroom cultivation. There have been literally hundreds of posts to the list serve over the last three years and is its still going strong. Some of the most active participants in the list serve are the three farmer advisors associated with this project (Sierigk, Rockcastle, and Laskovski). We have archived the postings from this list serve for nearly three years, and used some of these posting as quotations that appear in the BMP manual.

Discussion: As described above, this project began with 148 volunteers who attend the beginner-level workshops in 2010. The number of participants decreased sequentially from 185 (beginner level workshop) to 23 who participated in the implementation stage (100 log trial). This decrease in the number of participants at each stage was designed into the project. It does not (in most cases) indicated lack of satisfaction on the part of those did not progress to implementation, but rather the decrease was a process of honing in on those who were most qualified and most likely to succeed as commercial producers. In fact, many of the participants in the first two workshops had no expectation of income generation, but rather wanted to learn about mushroom cultivation at a hobby scale.

As unfortunate as it may be that 5 participants of the 15 who submitted expense/income data (described above, Table 2) incurred losses (negative income), is in no way a “disappointment” or failure from the sand point of the project, because from the outset we wanted find out what is a realistic success/failure rate for adoption of a shiitake enterprise. It is a given that not every adopter will be successful, but now we have a realistic estimate of what portion of typical beginners will or will not succeed.

During 2014, NE SARE authorized a no cost extension to the project to support outreach efforts related to this project. These included:
1.Additional printings of the publication Best Management Practices for Log-Based Shiitake Cultivation in the Northeastern United States. About 500 copies were made for distribution at the workshops and other events (see #2), specifically targeting interested beginning and existing farmers.

2. Support for six workshops, which trained 186 interested beginning and existing farmers over a total of 576 contact hours. The basic biology and process of shiitake inoculation, maintenance harvesting, and marketing was covered. Classes were held at six locations around New York: at the Cornell Arnot Research Forest, Cornell Campus and the MacDaniels Nut Grove, and at cooperative extension county offices in Greene/Columbia, Ontario, Oswego, and Delaware counties.Workshops were coordinated with county educators who collaborated with neighboring extensions to get the word out. All of the classes were filled to capacity and three of the four county workshops had a waiting list.

3.Edit, refine, publish, and promote factsheets and free video and print resources at http://mushrooms.cals.cornell.edu. This effort furthered the work of the grant by making research more accessible to our farmer audience.

Overall this non cost extension-related funding was essential and helpful in furthering the outreach and education component of the project as a whole. During the normal grant term, the focus was mainly on initial education and then data collection and processing. The extension allowed researchers and extension educations to get the results out and promote the potential of shiitake cultivaion in the Northeast.

• 2012 data
• Shittake production guide