10am David Stern, Rose Valley Farm and The Garlic Seed Foundation
1:30pm Grower Panel: Tom Vigue, Kiwihill Farm; Amy LeBlanc, Whitehill Farm; Mark Guzzi, Peacemeal Farm
A sclerotium (plural sclerotia, fromGreek skleros - hard) is a compact mass of hardened fungal myceliumcontaining food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until favorable growth conditions return. Sclerotia initially were mistaken for individual organisms and described as separate species until Louis René Tulasneproved in 1853 that sclerotia are only a stage in the life cycle of some fungi. Further investigation showed that this stage appears in many fungi belonging to many diverse groups. Sclerotia are important in the understanding of the life cycle and reproduction of fungi, as a food source, as medicine and in agricultural blight management.
Sclerotia are often composed of a thick, dense shell with thick and dark cells and a core of thin colorless cells. Sclerotia are rich in hyphae emergency supplies, especially oil. They contain a very small amount of water (5-10%) and can survive in a dry environment for several years without losing the ability to grow. In most cases, the sclerotium consists exclusively of fungal hyphae, whereas some may consist partly of fungal hyphae plexus and partly in between tissues of the substrate (ergot, Sclerotinia). Sclerotia sizes usually range from a few fractions of a millimeter to a few tens of centimeters. In favorable conditions, sclerotia germinate to form fruiting bodies (Basidiomycetes) or mycelium with conidia (in imperfect fungi). Sclerotia sizes can range from a fraction of a millimeter to a few tens of centimeters.
Inonotus obliquus (chaga mushroom) is a sclerotium growing mostly on birchtrees in northern climates. It has been used as a tonic and a remedy for thousands of years in Canada, Russia, Japan, etc. The tree sclerotium develops over the years as the mycelium sucks the energy of the living tree.
Sclerotinia sclerotiorum is a plant pathogenic fungus and can cause a disease called white mold if conditions are correct. S. sclerotiorum can also be known as cottony rot, watery soft rot, stem rot, drop, crown rot and blossom blight. A key characteristic of this pathogen is its ability to produce black resting structures known as sclerotia and white fuzzy growths of mycelium on the plant it infects. These sclerotia give rise to a fruiting body in the spring that produces spores in a sac which is why fungi in this class are called sac fungi (Ascomycetes). This pathogen can occur on many continents and has a wide host range of plants.
Sclerotium cepivorum is the fungus that affects Alliums and this link explains the problem.
