Improving the yield of cold-weather shiitake by irrigation
Work on this project to improve yields of cold weather shiitake strains has proceeded as planned. The first nine months have focused on putting in place the infrastructure that will be used to test the hypothesis that irrigation can improve the yields of cold weather shiitake by concentrating the fruiting period and improving quality of mushrooms. in spring and fall 2017. Three hundred logs have been inoculated with cold weather strains of shiitake (spring 2016) and a new laying yard set up for the project (summer 2017). Visual inspection in Fall 2017 shows a good rate of mycelium colonization across these logs. Irrigation options have been researched and discussed with the project adviser and the main irrigation line installed, with water being gravity fed from 2 shallow wells and a group of four 285 gallon storage tanks
The dry winter or 2015/16 and subsequent dry months in the summer has presented challenges and additional water storage capacity had to be purchased as the recharge rate of our existing wells was not sufficient to deliver the flow rate/duration we calculated for the size of laying yard, but we believe we now have sufficient capacity to deliver the irrigation.
A set of logs inoculated in in Spring 2015 was irrigated in October as test run for the full irrigation trials.
In Spring 2017 we will begin irrigating the logs during the natural fruiting cycles to encourage fruiting to concentrate over a period of days rather than weeks.
In spring 2016 300 logs we inoculated with 3 different strains of cold weather shiitake. Despite the dry conditions of spring and summer 2016, almost all logs are showing signs of strong mycelium growth.
In early summer a new laying yard was designed and built and the logs were set out in 9 groups, comprising 3 different tree species – maple, oak and beech, with each species subdivided in to 3 groups and each inoculated with a different shiitake strain.
The laying yard is approximately 50 x 50 feet, on a gentle slope, shaded by pines and shade cloth was further used as an additional measure to retain log moisture.
Work with our project adviser highlighted that current water recharge rate of our wells might not be sufficient to supply the planned irrigation regime. While this may be a short term problem due to starting levels being so low after the very dry winter of 2015/16, additional water storage capacity was purchased in the form of 4 x 285 gallon tanks.
In October we tested irrigation on a group of logs that had been inoculated in 2015 with mixed results (outlined later in this report)
We have met all our project milestones, having a strongly colonized group of logs to work on, a new area which will allow safe and easy movement between log stacks, and have installed the main irrigation line which brings water to the laying yard, using gravity.
Winter 2015/16 was very dry, and our surface wells water storage was much lower than previous years. Dry weather through 2016 meant that they never achieved full capacity and following discussions with the project adviser is was clear that additional storage capacity was needed. This has been installed and we have sufficient capacity to implement irrigation regimes as planned
In October we tested the irrigation on a group of 150 logs that were inoculated in 2015, before the current project began. Results of irrigation were mixed – irrigation did not seem to affect the period of time take for a log to fully fruit, but the quality of fruits grown under irrigation was clearly higher, both in terms of size of individual mushrooms and their texture, density and visual appeal.
Farming and Climate Change Project Coordinator
23 Mansfield Avenue
Burlington, Vermont 05401
Office Phone: 802 656 3495