Andrew M. Cuomo, Governor | Richard A. Ball, Commissioner
Jessica Ziehm

April 29, 2010

Commissioner Hooker Announces 2010 Strategy for Late Blight

State Coordinates Response for Detection & “Stop Sale” of Diseased Plants

New York State Agriculture Commissioner Patrick Hooker today announced a new concerted strategy that will enhance the State’s detection and eradication efforts of late blight, a plant disease that mainly attacks potatoes and tomatoes.  Late blight was the cause of much distress to backyard gardeners, as well as a significant production loss for New York’s commercial growers in 2009.

                “New York had the perfect weather combination of cooler temperatures and rainy days for the development of late blight last summer,” the Commissioner said.  “While not an uncommon plant disease in New York, its impact on the State’s potato and tomato crops had a devastating effect as it arrived earlier and stayed longer than normal.  Late blight was an even greater challenge to the State’s organic growers who did not have the approved control measures to combat this highly contagious disease in the field.”

                The Commissioner added, “In an effort to be more prepared for the possible introduction of late blight, the Department has met with industry stakeholders and leaders, as well as members from Cornell University’s Plant Disease Diagnostic Clinic and Cooperative Extension, to put into place a strategy that enables rapid detection, clear communication and an organized system to protect plant health this summer.”

                Over the past few months, the Department has thoroughly reviewed the 2009 outbreak of late blight, trained its horticultural inspectors on how to identify the disease, and put in place a strategy to reduce the spread of late blight, if it is introduced in New York in 2010.  The Department will be surveying plants at the retail level in stores as well as in commercial greenhouses, while Cooperative Extension will follow up with any suspect cases in the field from commercial growers or home gardeners.  Following are the specific action items the New York State Department of Agriculture and Markets has either already initiated or will be implementing this season:

  1. State Inspection Plan – Starting April 1st and continuing through the end of June, state horticultural inspectors have been visiting greenhouses and plant retailers throughout the State in order to document sources and inspect plants for disease.


  1. Letter to Distributors – Currently, the Department is notifying out-of-state plant distributors of the 2009 incident and seeking their cooperation in helping the New York State better understand where plant material is traveling to.  This will help inspectors prioritize inspections in upcoming months.
  1. Standardized Information – All horticultural inspectors and county cooperative extension offices have been asked to provide standardized information for suspect cases of late blight on plants in New York State.  The information gathered will include the location of the suspect plant, the type of symptoms, as well as other critical information, allowing a more coordinated follow up on possible infestations.


  1. Cooperative Reporting System – This year, the Department will have access to an electronic list serve maintained by Cooperative Extension to help ensure a swift and organized response in the event of late blight. 
  1. Interstate Communication – The Department will be reaching out to other states on a regular basis to stay abreast of potential late blight activity across the nation and to help coordinate responses if necessary.


                If late blight is detected in New York’s tomato or potato crop again this season, the suspect lot of plants will be subject to quarantine upon initial visible diagnosis by a state horticultural inspector and the product sample will be sent to the Plant Disease Diagnostic Clinic at Cornell University for confirmation.  If confirmed with late blight, the plants will be properly disposed of under state supervision and a trace back and trace forward will be initiated in order to try and locate other possibly infected plants. 

                In addition to the State’s efforts, Cornell Cooperative Extension will be aggressive in providing outreach and education to growers and gardeners on late blight, and the Plant Disease Diagnostic Clinic at Cornell University will be conducting all the testing of submitted plant samples for late blight.

                Late blight is a plant disease that mainly attacks potatoes and tomatoes, although it can sometimes be found on other crops, weeds and ornamentals, such as petunias, nightshades, and tomatillos.  Late blight was a factor in the Irish potato famine in the 1840’s, during which millions of people in Ireland starved or were forced to emigrate.  Late blight is caused by an oomycete pathogen that can produce millions of spores from infected plants, spreading readily with wet weather and high humidity.  Spores travel through the air, land on infected plants, and if the weather is sufficiently wet, cause new infections. Once infected, plants may wilt and die within three days.

In 2009, the strain of late blight was a problem for tomatoes primarily, as potato growers traditionally watch and prepare for it.  The disease got onto tomato transplants and moved quickly within the plant distribution system.  Presence of the disease, together with ideal wet weather, led to a quick and devastating spread of the disease.  Home gardeners, in particular, were caught completely unaware.  Commercial tomato growers were challenged to apply crop fungicides in time to prevent the outbreak. 

                For more information about identifying late blight and how to control it, please visit

2010 Press Releases