Scout your Bradford pears now for European pear rust

Keyword:
Publish time: 24th July, 2014      Source: Michigan State University Extension
Information collection and data processing:  CCM     For more information, please contact us
     

European pear rust has been found in southeastern Michigan this 2014 season.

    

Posted on July 23, 2014 by Heidi Wollaeger, Michigan State University Extension

     
European pear rust on Bradford pear. All photos Jan Byrne, MSU

European pear rust on Bradford pear. All photos Jan Byrne, MSU

  

First detected in Farmington, Michigan in 2008, European pear rust (Gymnosporangium sabinae) has been detected on Bradford pear (Pyrus calleryana) in southeast Michigan this season. The most severely affected cultivar is the Cleveland pear, which has a narrower growth habit than other pear cultivars. This compact growth habit reduces air circulation and creates a favorable environment for the growth of fungal diseases, such as European pear rust.

European pear rust can infect species of the pear and juniper genera, Pyrus and Juniperus. European pear rust on juniper has not been recorded in Michigan, but is fairly common in Europe. On pear species, the fungus has distinctive orange sporulation on the leaves occurring in the summer and early fall. On juniper, the fungus causes cankers on the stem which produce an orange gelatinous substance in the spring.

According to Michigan State University Extension, if European pear rust is detected in your nursery or landscape, prune out infected branches or remove the entire tree, depending on the severity of infection. Because the rust often overwinters on junipers, which provides a source of inoculum for the pear trees in the spring, try to inspect nearby junipers for cankers prior to the winter.

European pear rustNursery growers should separate pear and juniper species in the nursery to prevent cross-contamination if the disease has been found. Michigan State University Extension recommends a fungicide spray in the class of strobilurins, such as Trifloxystrobin (Compass), as a fungicide management strategy.

The above average precipitation throughout the state during June is conducive for fungal diseases, such as European pear rust. For example, the Commerce Township Enviro-weather station in southeast Michigan recorded 3.57 inches of rain throughout June, which is slightly above the average of 3.06 inches. On the west side of the state, the Sparta Enviro-weather station received 8.3 inches of rain during June which is exceedingly high compared to an average of 3.17 inches. Nursery growers or landscape professionals should be scouting all types of plants for fungal diseases now.

Michigan State University does not endorse products mentioned, nor is it a criticism of products not mentioned.

  

This article was published by Michigan State University Extension. For more information, visit http://www.cnchemicals.com/. To contact an expert in your area, visit http://www.cnchemicals.com/, or call 888-MSUE4MI (888-678-3464).

    

Related Articles

      
  •     

    Mites are becoming more active on conifers

        

    June 4, 2014 | Jill O'Donnell | Scouting now can help detect mite problems before their populations get large enough to cause bronzing of foliage and potentially reduce tree quality.

      
  •        
  •     

    2014 MSU Weed Tour takes place July 2

        

    June 3, 2014 | Christy Sprague | Participants can compare herbicide programs, evaluate weed management strategies, tour MSU research plots and participate in field presentations.

      
  •        
  •     

    Accurate identification is key to a successful pest management program

        

    May 9, 2014 | Marilyn Thelen | The foundation for any good pest management program should be accurate identification of the pest. Early identification provides time to monitor pests and determine the best plan of action.

      
  •        
  •     

    Deciphering the Agriculture Act of 2014 - Farm Bill

        

    March 14, 2014 | Dennis Stein | Farmers scramble to learn more about the new Agriculture Act of 2014 or "Farm Bill' before planting season starts.

      
  •        
  •     

    MDARD pesticide applicator recertification credits now available online

        

    February 14, 2014 | James DeDecker | Pesticide applicators in Michigan can now keep their certifications current with minimal investment in time and travel.

      
  •   
  

Related Events