Myrothecium verrucaria
Encyclopedia
Myrothecium verrucaria is a plant pathogen
. It is common throughout the world, often found on materials such as paper, textiles, canvas and cotton. It is a highly potent cellulose decomposer.
It has been formulated into a pesticide for control of nematode
s and weed
s. The pesticide's active ingredient is a mixture of the killed fungus, M. verrucaria, and the liquid in which the fungus was grown. The dead fungus kills specific parasitic microscopic
pests called nematodes, which attack plants, usually through their roots. The active ingredient is specific, being effective only against nematodes that parasitize plants; it does not harm free-living nematodes. Because the mixture may be toxic to aquatic
organisms, it is not approved for use in or near bodies of water. No harmful effects to humans are expected as long as applicators protect their eyes and skin from contact with pesticide products that contain this active ingredient.
Since 1998, the United States Department of Agriculture
, Agricultural Research Service
(ARS) has experimented with using M. verrucaria as a biologically-based herbicide against kudzu
vines. A spray based on M. verrucaria works under a variety of conditions (including the absence of dew
), causes minimal injury to many of the other woody plants in kudzu-infested habitats, and takes effect fast enough that kudzu treated with it in the morning starts showing evidence of damage by mid-afternoon. Initial formulations of the herbicide produced toxic levels of trichothecene
as a byproduct, though the ARS discovered that growing M. verrucaria in a fermenter on a liquid instead of a solid diet limited or eliminated the problem.
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
. It is common throughout the world, often found on materials such as paper, textiles, canvas and cotton. It is a highly potent cellulose decomposer.
It has been formulated into a pesticide for control of nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s and weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s. The pesticide's active ingredient is a mixture of the killed fungus, M. verrucaria, and the liquid in which the fungus was grown. The dead fungus kills specific parasitic microscopic
Microscopic
The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:...
pests called nematodes, which attack plants, usually through their roots. The active ingredient is specific, being effective only against nematodes that parasitize plants; it does not harm free-living nematodes. Because the mixture may be toxic to aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
organisms, it is not approved for use in or near bodies of water. No harmful effects to humans are expected as long as applicators protect their eyes and skin from contact with pesticide products that contain this active ingredient.
Since 1998, the United States Department of Agriculture
United States Department of Agriculture
The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
, Agricultural Research Service
Agricultural Research Service
The Agricultural Research Service is the principal in-house research agency of the United States Department of Agriculture . ARS is one of four agencies in USDA's Research, Education and Economics mission area...
(ARS) has experimented with using M. verrucaria as a biologically-based herbicide against kudzu
Kudzu
Kudzu is a plant in the genus Pueraria in the pea family Fabaceae, subfamily Faboideae. It is a climbing, coiling, and trailing vine native to southern Japan and southeast China. Its name comes from the Japanese name for the plant, . It is a weed that climbs over trees or shrubs and grows so...
vines. A spray based on M. verrucaria works under a variety of conditions (including the absence of dew
Dew
[Image:Dew on a flower.jpg|right|220px|thumb|Some dew on an iris in Sequoia National Park]]Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening...
), causes minimal injury to many of the other woody plants in kudzu-infested habitats, and takes effect fast enough that kudzu treated with it in the morning starts showing evidence of damage by mid-afternoon. Initial formulations of the herbicide produced toxic levels of trichothecene
Trichothecene
Trichothecenes are a very large family of chemically related mycotoxins produced by various species of Fusarium, Myrothecium, Trichoderma, Trichothecium, Cephalosporium, Verticimonosporium, and Stachybotrys...
as a byproduct, though the ARS discovered that growing M. verrucaria in a fermenter on a liquid instead of a solid diet limited or eliminated the problem.