For years, mushroom cultivation has been a good source of additional income for our farmers. As such, it is one of the technologies that was capitalized during the extended lockdowns brought by the COVID-19 pandemic. In Isabela and Cagayan, the DA-Regional Crop Protection Center (RCPC) outscaled the straw mushroom (Volvariella volvacea) cultivation in containers benefiting 100 households and 83 technology adopters. 

This technology was highlighted at the DA-BAR in-house webinar on 14 September 2022 conducted via Webex and Facebook live. Science research specialist Nellie R. Dadufalza of DA-Cagayan Valley explained the process of straw mushroom cultivation and answered questions from the live viewers. 

The materials needed to start the straw mushroom cultivation are substrates (ie. freshly harvested dried rice straw or banana leaves), containers for soaking, plastic roll bag, plastic basket, and steel drum for pasteurization. 

The first step is to collect dried banana leaves or rice straw. Dadufalza stressed that only the dried banana leaves attached to the tree should be used. While for the rice straw, freshly threshed and sun dried for three to five days. 

The next step is to soak the banana leaves or rice straw in clean water for 10 to 14 hours and three to four hours, respectively. Dadufalza said that rice straw has to be pasteurized by boiling or steaming it for one hour to avoid contamination. 

Next step is to drain the excess water from the banana leaves or rice straw for five minutes. This is followed by inoculating the mushroom spawn into the substrate. To do this, the banana leaves or rice straw should be arranged and pressed in the plastic basket until it reaches 10-centimeter height. Then, the spawn is placed around 3-5 cm from the edge of the basket. This process will be repeated for at least four times or until it reaches the top of the plastic basket. 

 After this, rice bran or cassava flour will be sprinkled to provide food and additional nutrients. Used paper such as carton and paper sacks can also be placed to serve as substrate fillers. These should be soaked in clean water for at least one hour before using. 

The next step is to put the plastic basket inside a plastic bag and tightly tie it to maintain the high temperature inside. The baskets are then placed in a cool dry place away from ants and termites. After four to five days, cut three around 3-cm slits to allow excess heat to escape. 

After 10 to 14 days, mushroom buttons can now be harvested. To do this, remove the tie and slightly open the plastic then pick the mushroom buttons. Once done, Dadufalza stressed the importance of closing the plastic bag immediately to avoid too much exposure of the sprouting pinheads. Harvesting can be done two to four times, after that the substrate can now be placed on the vermicomposting area. 

According to the profitability analysis conducted by the DA-RCPC, the production cost of the three basket-straw mushroom cultivation for one cycle is PhP 429.25 with a 25.19% return on investment (ROI). While for the second cycle, the production cost is PhP 374.25 with a 60.3% ROI. (### Rena S. Hermoso)