White Rot and the Quarantine Zone, revisited

This is a revised version of a post I wrote in July 2013 during the inaugural year of Awkward Botany.

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It’s garlic planting season in the northern hemisphere. A few years ago, while helping out with the garlic harvest at a local farm, I had the chance to learn about some of the challenges involved in growing garlic in southern Idaho. Apart from the fact that it is a very labor intensive crop to grow, one of the major challenges stems from a disease called white rot – easily one of the worst diseases that garlic and onion growers face.

White rot is caused by a fungus (Sclerotium cepivorum), and it affects all plants in the Allium genus, including garlic, onions, chives, and ornamentals. The disease causes the leaves of alliums to die back, their bulbs to decay, and their roots to rot, ultimately turning the plants to mush. Sclerotia, the dormant stage of the fungus, are small (about the size of a poppy seed), black, spherical structures that can survive in soil for more than 20 years. They remain dormant until the exudates of allium plants awaken them, at which point they begin to grow, unleashing their destruction. Sclerotia can be moved around by farm equipment, floods, irrigation water, wind, and by attaching themselves to plant material. Once this fungus has established itself in a field, it is extremely difficult to eradicate, making the field virtually unfit for allium crops.

The threat of white rot and the monetary damage that it can cause led to the establishment of a quarantine zone in southern Idaho in order to protect its $55 million dollar a year onion industry. Due to the quarantine zone (which encompasses 21 counties), all garlic that is grown for seed within the zone must be inspected and certified. [“Seed” in this case refers to the garlic cloves themselves; onions, on the other hand, are grown from actual seeds and are not subject to the same protocol.] Any seed garlic that is brought into the zone must go through a rigorous testing process in order to ensure that it is free of the white rot pathogen before it can be planted. Garlic is a specific threat because the cloves can readily carry sclerotia, compared to onion seeds, which are not likely to harbor them.

This process significantly limits the amount and variety of garlic that can be grown in the quarantine zone. While the quarantine is essential for warding off the threat of this particular pathogen, it stifles the garlic growing industry and makes it difficult for new garlic growers to establish themselves.

Garlic farming is already incredibly demanding due to the amount of time and physical labor that goes into planting, harvesting, drying, grading, etc. The quarantine, while understandable, is an added challenge. Learn more about this issue by listening to this story on PRX.

See Also:

Garlic emerging in the spring.

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Documentary: Know Your Mushrooms

Earlier this month, the 33rd annual Telluride Mushroom Festival took place in Telluride, Colorado. This is an event that draws in hundreds (thousands, perhaps?) of fungi enthusiasts. As a budding fungi enthusiast myself, I get excited when I hear tale of gatherings such as these, and while I did not make it out this year, the Telluride Mushroom Festival is high on my list of things to attend sometime in the years to come.

My fascination with fungi started shortly before I headed to graduate school in Illinois in 2009. I had just read about mycoremediation in a book called Toolbox for Sustainable City Living, and that, along with what I had learned about soil fungi in my college soils courses, had me very curious about the world of mycology. I have yet to spend the kind of time that I would like to on this subject, but it remains of great interest to me.

A couple years ago I was writing weekly recommendations on my previous blog, the juniper bends as if it were listening. One of my weekly recommendation posts was about a documentary film called, Know Your Mushrooms. I am reposting that review  here in honor of this month’s mushroom festival in Telluride, and because I think it’s a film worth watching. No, it is not about plants per se, but it is about a kingdom of living things that regularly interacts with plants. Not only that, but it’s about a major player in the ecology of practically every ecosystem on earth. Bottom line: if you are at all interested in the natural world, you will be interested in this film.

know your mushrooms

Mushrooms freaks, fungiphiles, and myco-fanatics alike are all probably well aware of this fantastic documentary film by Ron Mann entitled, Know Your Mushrooms, but for uninitiated folks and novices like myself, this is a great introduction. This film will acquaint you with a peculiar crowd of mushroom lovers and fungus aficionados, where you will marvel in their uniqueness and their vast knowledge concerning the fascinating world of mycology. Mann bases his film around his visit to the Telluride Mushroom Festival in Colorado, where mushroom fans have gathered annually for many years now to celebrate and revel in the fungal world. Mann converses with several mushroom experts and enthusiasts, but spends most of his time with self-proclaimed guru, Larry Evans. Alongside Evans, Mann explores numerous mycological topics, including mushroom hunting, mushroom cooking, poisonous mushrooms, psychedelic mushrooms, mushroom folklore, mushroom health benefits, and the ecological and environmental benefits of fungi (mycoremediation!). This is a very well-produced and well-directed film, maintaining the interest and attention of the viewer as it transitions from one aspect of mushroom culture to another, simultaneously providing education and entertainment throughout. If your viewing experience is anything like mine, by the time this film is over, you will be wishing that you were as knowledgeable about mushrooms as the folks featured in this film. As a result of watching Mann’s documentary, I have vowed to redouble my efforts and commit myself to the study of mycology so that one day I can join fellow fungus freaks in a celebration of this magnitude. Perhaps you will join us…

Morels harvested on the forest floors of Illinois

Morels harvested on the forest floor of Illinois

White Rot and the Quarantine Zone

It’s garlic harvesting season in the northern hemisphere, so recently while helping out with the harvest at a local farm, I had the chance to learn about a challenge involving growing garlic in southern Idaho. The challenge stems from a disease called white rot. It’s caused by a fungus (Sclerotium cepivorum), and it affects all alliums, including garlic, onions, chives, and ornamental alliums. This disease causes the leaves of alliums to die back, their bulbs to decay, and their roots to rot, ultimately turning the plants to mush. Sclerotia, the dormant stage of the fungus, are small (about the size of a poppy seed), black, spherical structures that can survive in soil for more than 20 years. They remain dormant until the exudates of allium plants awaken them, at which point they begin to grow, unleashing their destruction. Sclerotia can be moved around by farm equipment, flood and irrigation water, wind, and by attaching themselves to plant material. Once this fungus has established itself in a field, it is extremely difficult to eradicate, making the field virtually unfit for allium crops.

The threat of white rot and the monetary damage that it can cause led to the establishment of a quarantine zone in southern Idaho in order to protect its $55 million dollar a year onion industry. Due to the quarantine zone, all garlic that is grown for seed within the zone must be inspected and certified, and any garlic seed (i.e. garlic cloves) that are brought into the zone must go through a rigorous testing process in order to be certain it is free of the white rot pathogen before it can be planted. Garlic is a specific threat, because while onions in the zone are typically grown from seed and so are largely free from harboring sclerotia, garlic is grown from cloves, which can readily carry sclerotia. This process significantly limits the amount and the variety of garlic that can be grown in the quarantine zone. While the quarantine is essential for warding off the threat of this particular pathogen, it stifles the garlic growing industry and makes it difficult for new garlic growers to establish themselves.

Growing garlic is already an incredibly challenging pursuit due to the amount of time and physical labor that goes into planting, harvesting, drying, grading, etc. The quarantine, while understandable, is yet another added challenge. Learn more about this issue by reading this article found at Northwest Food News.

garlic

photo credit: wikimedia commons