- Miscellaneous: mushrooms
- Crop Production: agroforestry, forest/woodlot management
- Education and Training: on-farm/ranch research
- Pest Management: integrated pest management
Non-native trees are common in the rural landscape, often planted for shade or as ornamentals. However, by their very nature as non-native introductions, they arrive without natural enemies to keep their populations in check and many species can spread from a few scattered trees to dense stands if not managed. In Florida, almost one-third of the plants growing wild in Florida are non-native and some of these have become serious problems.
Removal of invasive species, especially trees, is often time consuming and expensive. For example, from 1998-2004, the Florida Department of Environmental Protection (DEP) spent almost $0.75 million treating Chinese tallow on 4,000 acres of natural areas in north and central Florida. Even for a private landowner or small farmer, the cost of cutting down invasive trees and removing the waste generated by branches and trunks consumes resources in time, effort, personnel, and finances; negatively impacting farm sustainability. To help offset some of these expenditures for small farmers, we propose to evaluate the potential of using non-native tree logs, common to the southern region, to produce edible and marketable mushrooms; turning unsustainable non-native tree species into a sustainable, small farm commodity.
Three invasive species are targeted in this study. Two species are Category I Florida invasives (tallow is also classified as a state noxious weed), and the other species is a Category II Florida invasive and has poisonous fruits if ingested by humans.
Chinese tallowtree (Triadica sebifera) – Tallow was introduced into Georgia in the late 1700’s and is now invasive throughout the southeastern US where it forms dense stands in mesic prairies, and floodplain forests. It is listed as a Category I “most invasive plant species” by the Florida Exotic Pest Plant Council. Chinese tallow is considered a Noxious Weed by the Florida Department of Agriculture and Consumer Services (FDACS), meaning propagation, commerce, and transport is prohibited.
Mimosa tree (Albizia julibrissin) – Introduced from China to US in 1745 and Florida in 1883, mimosa is widely cultivated as an ornamental. However, due to its tendency to readily establish in a variety of habitats after escaping from cultivation, mimosa is considered a Category I “most invasive plant species” by the Florida Exotic Pest Plant Council. Restrictions on planting exist in Okaloosa and Seminole counties in Florida.
Chinaberry tree (Melia azedarach) – Chinaberry was released in the early 1800s as an ornamental, planted in many southern states, and now occurs north to Virginia and west to Oklahoma. Chinaberry occurs primarily in disturbed areas (right-of-ways and fencerows), but also invades floodplain hammocks, marshes, and upland woods, and is listed as a Florida Category II invasive that has “increased in abundance … but not yet altered Florida plant communities”. Fruits are highly poisonous if ingested by humans, but birds readily spread the seeds without harm.
Project objectives from proposal:
Cultivation of gourmet edible and medicinal mushrooms has gained popularity throughout the southeastern US. Many small farmers have begun cultivating mushrooms using logs from native tree species as a substrate for mushroom mycelium. These mushrooms are often sold at farmers markets, through CSA’s, and directly to restaurants which promote the use of locally grown fresh produce. Many of these restaurants are identified as “gourmet” establishments and pay high prices for quality fresh ingredients. In addition to direct marketing of edible mushrooms, a web search revealed more than 25 companies marketing fungal spawn to small growers in the US.
While much is known about cultivating mushrooms on native trees, little is known about the possibility of cultivating mushrooms on logs of invasive trees. A previous SARE grant in Ohio determined that standing wood from the invasive tree-of-heaven tree (Ailanthus altissima) supported mycelia growth of oyster mushrooms (Pluerotus ostreatus) and chicken-of-the-woods (Laetiporus sulphureus). Trees were girdled, inoculated in place, and mushrooms harvested for sale at a local farm. This project demonstrated that mushrooms could be grown on an unconventional log substrate, an invasive tree species, resulting in financial return, sustainable benefits, and management of a non-native invasive species. Such an outcome may increase motivation for land managers, homeowners, and small farmers to reduce invasive species by cutting down non-native trees on their land for mushroom cultivation. Furthermore, if edible fungi perform well on non-native species, it may convince mushroom cultivators to utilize wood from invasive trees that would otherwise be discarded, thus making efficient use of an on-farm resource.
In February 2014, a pilot study was initiated to evaluate the ability of two common fungi species to successfully inoculate logs from three invasive tree species and produce edible mushrooms. We were also interested in comparing the mushroom production on the non-native species against a native tree species commonly used by small farm shiitake cultivators in north Florida. The two common fungi species used for mushroom cultivation were golden oyster (Pleurotus cornucopiae) and shiitake (Lentinula edodes). The three non-native tree species were paperbark (Melaleuca quinquenervia), Chinese tallow (T. sebifera), and acacia (Acacia auriculiformis). The native (control) species was water oak (Quecus nigra). Mycelial growth was recorded on all four species of trees during the summer 2014. At the current time (November 2014) mushroom fruiting has been initiated and small harvests of shiitake have been gathered from oak and tallow. Normal mushroom production on outdoor logs involves cutting trees and inoculating logs before leaf break, mycelial growth during the summer, and mushroom fruiting initiated with cool fall nights and continuing into spring.
Since favorable outcomes were obtained with mycelial growth in all tree species and initial mushroom production in tallow was comparable to oak, we propose to expand the study with small farmers in the north Florida and southern Georgia area. We will measure not only the capability for non-native trees to produce edible mushrooms, but evaluate the marketability and economic return of this product for small farmers.