Blister Spot
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(1/17/17) Testing for the exact cause of what appeared to be emaravirus on coffee in Kona, was inconclusive. However, Dr. Melzer and team were able to locate a publication that described the symptoms of emaravirus that we were seeing in Kona.
It appears that the causal agent may be the fungus, Colletotrichum gloeosporioides PENZ. and that this disease is called "Blister Spot". Blister Spot is transmitted through seeds and the presence and intensity of the disease can vary with genetic diversity. Eriophyid mites may be a vector of this disease. Pitting occurs on the berries of infected trees. Young fruit |
may be aborted or ripen prematurely. When premature ripening occurs, the beans often do not fill out properly and will create "floaters" during wet mill processing. Floaters and non-uniform beans can damage roasts and cause off-flavors.
Blister Spot publications:
We would like to continue to learn about this disease. Please contact Andrea at 808-322-4892 or andreak@hawaii.edu if you suspect Blister Spot or see these symptoms on your coffee plants.
What happened in the past?
(2014) Dr. Michael Melzer of UH CTAHR tested coffee leaves and branches from 3 farms showing symptoms like that in the photo to the left. Some of the tests resulted in a positive outcome for Emaravirus and others had a negative outcome for the disease. There is currently no pattern to the positive or negative results, and there does not seem to be a pattern to the farms or trees displaying these spotting and pitting symptoms.
One farm in Holualoa and two farms in the Captain Cook area were found to have Emaravirus or these symptoms on coffee. All trees with visual symptoms have been destroyed. Thank you to HDOA, CTAHR, and the complete cooperation of the farm owners!!!
For the past news release on Emaravirus on coffee in Hawaii, please visit http://hawaiitribune-herald.com/news/local-news/new-coffee-pest-identified.
Blister Spot publications:
- Diagrammatic scale for blister spot in leaves of coffee tree (de Oliveira Freitas et al. 2015)
- Genetic transformation with the gfp gene of Colletotrichum gloeosporioides isolates from coffee with blister spot (Armesto et al. 2012)
We would like to continue to learn about this disease. Please contact Andrea at 808-322-4892 or andreak@hawaii.edu if you suspect Blister Spot or see these symptoms on your coffee plants.
What happened in the past?
(2014) Dr. Michael Melzer of UH CTAHR tested coffee leaves and branches from 3 farms showing symptoms like that in the photo to the left. Some of the tests resulted in a positive outcome for Emaravirus and others had a negative outcome for the disease. There is currently no pattern to the positive or negative results, and there does not seem to be a pattern to the farms or trees displaying these spotting and pitting symptoms.
One farm in Holualoa and two farms in the Captain Cook area were found to have Emaravirus or these symptoms on coffee. All trees with visual symptoms have been destroyed. Thank you to HDOA, CTAHR, and the complete cooperation of the farm owners!!!
For the past news release on Emaravirus on coffee in Hawaii, please visit http://hawaiitribune-herald.com/news/local-news/new-coffee-pest-identified.
Collecting Plant Disease and Insect Pest Samples for Problem Diagnosis
Learn how to best collect and submit disease, insect, mite and nematode samples to the UH Agricultural Diagnostic Service Center (ADSC) for diagnosis. Click here for ADSC analytical service fees.
Learn how to best collect and submit disease, insect, mite and nematode samples to the UH Agricultural Diagnostic Service Center (ADSC) for diagnosis. Click here for ADSC analytical service fees.
Coffee Leaf and Soil Sampling
Learn how to correctly sample and submit coffee leaf and soil samples for proper analysis of plant nutritional status and and soil pH and nutrient status.
Learn how to correctly sample and submit coffee leaf and soil samples for proper analysis of plant nutritional status and and soil pH and nutrient status.
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