Plant disease

What’s breakfast without a glass of orange juice?

by Andrzej Czarniecki, Sustainable Plant Systems major

Photo Credit: Tim R. Gottwald and Steve M. Garnsey - USDA, ARS, U.S. Horticultural Research Laboratory, Florida

Photo Credit: Tim R. Gottwald and Steve M. Garnsey – USDA, ARS, U.S. Horticultural Research Laboratory, Florida

Orange juice may soon be a thing of the past. International researchers along with University of Florida and Florida State University researchers have received a 4 million dollar grant from the USDA in order combat Candidatus Liberibacter spp.  a devastating bacterial disease also known as Citrus Greening, or huanglongbing (HLB), or yellow dragon disease, which is known all around the world, affecting many other citrus growing countries and with no cure known. It is slowly killing off large orange production fields of Florida with up to 162,000 acres, as far as 50% of production has been cut in the last 4 years due with a $7.8 billion in revenue lost since 2007.

The disease enters the tree through a sap-sucking insect known as Diaphorina citri, the Asian Citrus Psyllid which feeds on the foliage of the plant allowing the bacteria to enter into the vascular system via the phloem and causing it to clog up. This causes the tree to starve itself from supplying proper nutrients resulting in fruit that is inferior in size, green, bitter which doesn’t allow for sales in the fruit market. There have been limitations such as not being able to culture the bacteria to send the bacteria to other researchers slowing down the process of finding a cure, therefore; scientists are trying a number of alternative different paths, such as; using  a bacteria similar in their study trials or by genetically modifying citrus trees with resistant genes from a spinach plant.

Reference
Researchers share $4 million USDA grant to attack citrus greening

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This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

Panama Disease is Driving Scientists ‘Bananas’

Banana2by Elizabeth Callow, Sustainable Plant Systems: Agronomy

Chances are, if you ate a fruit this morning, it was likely a banana. Bananas are one of the most readily available fruits in the word, boasting high vitamin and nutrient contents. Since the 1950’s, only one variety of banana has been readily available on the global market. This banana is commonly called the Cavendish banana, named after the family who first propagated it in the United Kingdom.

Tropical Race 4 of Panama disease has been known to exist for nearly 50 years. However, it hasn’t been until recently that this has posed a major problem for banana suppliers. Panama disease is a type of Fusarium wilt, and once it is present in a location it is nearly impossible to eradicate. Tropical Race 4 is related to Tropical Race 1, which completely wiped out the Gros Michel banana (the predecessor to the Cavendish banana) in the 1950s. Unless a resistant variety is found, banana production could be severely altered in the coming months and years.

These issues are largely a result of excluding diversity in the banana population. Bananas are propagated as clones, so there is virtually no genetic diversity in the banana population. This creation of a monoculture has been observed in several prominent historical events. Examples of such events include the Irish Potato Famine and Dutch Elm Disease. While the loss of the banana will not lead to a worldwide food shortage, it is imperative to learn from our mistakes and ensure that diversity is a top priority to maintain good health in our crops.

Links for Further Exploration
Our Favorite Banana May Be Doomed; Can New Varieties Replace It? NPR
Bye Bye Bananas – The Washington Post
The Most Popular Eating Banana Might Soon Go Extinct

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This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

Thousand Cankers Disease Hits Ohio

Curtis Utley, CSUE, Bugwood.org

Image: Curtis Utley, CSUE, Bugwood.org

by Stephen Marinkov, Communications major

Being from Ohio it is important for the natives to be educated on invasive species that can harm the state.  Thousand Cankers Disease is an invasive species caused by the fungus Geosmithia morbida.  The fungus is carried by the walnut twig beetle that bores into the trees, killing walnut and butternut trees in Ohio.

This fungus causes thousands of small cankers to form under the bark of the tree; the cankers eventually close up.  When this happens, nutrients and water intended for the branches and stem are cut off, killing the trees.
The Black walnut and butternut trees are most susceptible to the disease and natives should be informed of the symptoms.  Homeowners (?) should be aware of yellowing foliage where the leaves turn yellow and thinning in the upper crown of the infested tree.

Major spread of this disease is caused by human movement of wood products.  Natives need to be aware of the infected trees and limit the movement of potential infected trees.  The Great Lakes Early Detection Network (GLEDN) smart phone app is available as a free download.  This app contains images of Thousand Cankers Disease that users can look at to investigate possible infected trees.

As an Ohio native I want to spread awareness about invasive species that could harm this state.  If natives work together and combat diseases head on we can limit the deaths of so many trees.

More info > Ohioline Thousand Cankers Fact Sheet

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This blog post was an assignment for  Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

Where there are plants, there are plant diseases

diseaseheadlines2

Plant diseases impact all countries on all continents, including Antarctica.  For the Celebration of Nations event in the College of Food, Agricultural, and Environmental Sciences, I placed several news headlines on a world map to convey the global scope of plant pathology.

Scanning the headlines, many people were surprised – and concerned. Even plant pathologists were impacted by all of the headlines in one place, on one world map.  And this is a very short list.

We were honored to receive the “Most Educational Display” award at the event for this display.  My colleagues suggested that this is a good visual way to get the message out about the importance of plant pathology, and so I choose this blog post as a way to start.  Yes! Coffee, chocolate, bananas, oranges . . .  wheat, rice, corn and more – they are all on the list.

Read more
Tackle Fungal Forces to Save Crops, Forests and Endangered Animals > Science Daily
American Phytopathological Society on Twitter > News

 

Noticing the Brown-Tipped Evergreens

diplodia tip blight

Wallis et al. Ohioline Fact Sheet Diplodia Tip Blight

Winter is really the season for the evergreen trees.  There’s nothing like the beauty of snow-covered pines, spruces, firs – they are the stuff of winter landscape!

This brings me to a common disease of pines – Diplodia tip blight, caused by the fungus, Diplodia pinea. Austrian pines are particularly suspectible.  If you’ve seen an Austrian pine tree, you’ve probably seen clumps of brown needles – that’s likely the work of the fungus.  Austrian pines are often planted as street trees in this part of the country because they are tolerant to the road salt used for winter ice/snow control.

PhD candidate Patrick Sherwood and Professor Enrico Bonello in the Department of Plant Pathology are using the Diplodia-pine system as a model to study plant defense against pathogens.  They are delving down to the biochemical and molecular levels to study the complex, intriguing interactions between plant and fungus.

Many students are surprised to discover that plants indeed mount a defense response against pathogens. It’s not the same as the immune system of humans and animals, but there are key similarities as well as differences.

The use of disease resistant plants or crops is a cost-effective, environmentally sound management strategy.  An ounce of prevention is worth a pound of cure – that’s especially true for plants.

Related article:
Diplodia tip blight > Ohioline Fact Sheet

“Could Drones Help Protect Apple Orchards From Disease?”

Strangest use for drones everThis recent tweet by Huffington Post (right)  caught my eye. I was surprised to find out it was a story about plant pathology research led by alumni Kirk Broders (PhD Ohio State, Plant Pathology) and his PhD student, Matthew Wallhead (BS and MS, Ohio State, Plant Pathology), now at the University of New Hampshire.

Broders and Wallhead are developing an unmanned aerial vehicle (UAV) – AKA drone – to scout orchards for a serious disease, apple scab. Broders hopes to develop a smaller, more affordable device to detect diseases and other problems.

The development of aerial devices in plant disease management isn’t entirely new, but this particularly story is getting a lot of attention in the press. On our Plant Pathology Facebook page, it is by far our most popular post in recent months.  Although Broders and Wallhead are careful not refer to their device as a drone, it’s certainly hooked a lot of people.

Drone, unmanned aerial vehicle, remote control imaging device.  In the world of Twitter and newsfeeds, headlines do matter.  I hope you’ll click through on the link and learn a little bit about what the work of plant pathology. Now that’s what really matters!
> Read more