Nathan Kleczewski, Extension Specialist – Plant Pathology; firstname.lastname@example.org, Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland; email@example.com and Andy Wyenandt, Specialist in Vegetable Pathology, Rutgers University; firstname.lastname@example.org
As mentioned earlier, Dickeya dianthicola has been detected in Delaware in three fields of ‘Vivaldi’ potatoes this season. In addition D. dianthicola has been found in ‘Reba’, ‘Snowden’ and ‘Norwis’ on 3 farms in New Jersey and has also been detected in fields with seed originating from Maine on 5 farms on Long Island in ‘Reba’, ‘Vivialdi’, ‘Superior’, ‘Norwis’, and ‘Waneta’. The pathogen has been detected in NJ, NY, PA, MD, VA, NC, WV, and FL this summer on seed from Maine and New Brunswick, Canada (NJ and VA). Maine potatoes are currently shipped to over 20 states across the country (CA, CT, FL, ID, IN, KY, MD, MA, MS, NH, NJ, NY, NC, OH, PA, RI, TN, VT, VA, WA, WV, and WI). Potato growers, crop consultants, and Extension personnel in states which grow Maine potatoes should remain vigilant by scouting their fields for Dickeya symptoms on a regular basis and by submitting any suspect samples for diagnostic testing. D. dianthicola has been detected in the US in the past, and because of this, APHIS just recently announced that the pathogen has been designated as a non-reportable/non-actionable pathogen despite its potential to cause 100% crop loss. A link to the USDA/APHIS website for information on D. dianthicola detection and control can be found at this address: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/sa_nematode/sa_potato/ct_dickeya.
It is important to understand that this is a seed piece issue and that documentation of its presence will assist all in the potato industry, from seed producers to growers, in addressing the situation in a timely fashion. If you see any symptoms of black leg or had issues with poor emergence, contact Dr. N. Kleczewski (email@example.com) Dr. K. Everts (firstname.lastname@example.org) or your county agriculture agent. We will ensure that the samples are sent for appropriate testing for the presence of Dickeya. In addition to testing, it is important that you have your seed health certificate. This certificate will indicate the source of your potatoes and the lot of origin. This information is being collected across the potato growing region to further identify problematic seed sources.
For more information on Dickeya please see the following articles posted at the Delaware Field Crops Disease Management Blog: http://extension.udel.edu/fieldcropdisease/?s=Dickeya