black walnut diseases
I have a black walnut who an arborist looked at and suspects thousand cankers disease. Do I need to test nut or branch to be positive? there are 3 other black walnut trees down the street that have died. Thanks, Pamela
Thousand cankers can be diagnosed with fairly high certainty by looking for beetle activity and or the cankers which cause the disease. See details on biology, diagnosis and management at -
http://pnwhandbooks.org/plantdisease/walnut-juglans-spp-thousand-cankers-disease-black-walnut-decline. If you would like confirmation, you can bring samples to the OSU Master Gardener Plant Clinic in Hood River located at 2990 Experiment Station Drive. The clinic is staffed on Monday from 1 to 4 pm and Thursday from 8 am to noon and 1 to 4 pm. You can drop samples off Mon-Fri from 8 am to noon and 1 to 5 pm.
Alternatively, you can submit samples to the OSU Plant Clinic in Corvallis. General info for submitting plant samples is - http://plant-clinic.bpp.oregonstate.edu/submit#plant.
Sample submission form is available at - http://plant-clinic.bpp.oregonstate.edu/files/plant_clinic/2015%20Plant%20Dis%20Form_revised_5-5-16.pdf.
Feel free to call or email if you have questions. My contact information is included below.