Featured Research

from universities, journals, and other organizations

Solutions to common pear fungal disease

Date:
December 28, 2010
Source:
American Society for Horticultural Science
Summary:
Diseases caused by a species of fungus called Phytophthora syringae are responsible for significant economic losses on a wide range of plants, including pear. Recent field observations by growers suggest that increased nitrogen content in nursery trees resulting from foliar sprays with urea in the autumn increases tree susceptibility to infection. New research in this area investigates the specific form of nitrogen, delivery method, or timing of nitrogen applications.

Diseases caused by a species of fungus called Phytophthora syringae are responsible for significant economic losses on a wide range of plants, including pear. In the Pacific Northwest region of the United States, disease occurs during the winter in nursery stock, especially on trees that are harvested and stored in coolers or in outdoor sawdust beds. Recent field observations by growers suggest that increased nitrogen content in nursery trees resulting from foliar sprays with urea in the autumn increases tree susceptibility to infection by Phytophthora syringae.

The results of new research suggest the relationship between tree susceptibility to P. syringae and tree nitrogen concentration may be specific to the form of nitrogen, delivery method, or timing of nitrogen applications.

Researchers from Oregon State University's Department of Horticulture and the USDA-Agricultural Research Service published a study in HortTechnology that contains new answers for nursery operators. The experiments investigated the effects of soil nitrogen (N) availability and spraying pear trees with combinations of urea, chelated copper ethylenediaminetetraacetic acid (CuEDTA), and phosphonate-containing fungicides on stem N concentration and susceptibility to infection by P. syringae.

Experimental results showed that spraying trees with urea in the autumn increased concentrations of nitrogen and amino acids in stems and had no significant effect on tree susceptibility when stems were inoculated with P. syringae before or after urea sprays. Spraying with CuEDTA decreased stem nitrogen concentrations and had no significant influence on tree susceptibility to P. syringae when stems were inoculated before or after CuEDTA sprays, while spraying with fungicides containing fosetyl-aluminum in October or November decreased tree susceptibility to P. syringae. The effects of fungicides containing fosetyl-aluminum on susceptibility were similar regardless of whether trees were sprayed or not with urea or CuEDTA. According to the report, the results suggest that these fungicides can be used in combination with urea or CuEDTA sprays for reducing disease severity caused by P. syringae without impacting growers' objective of increasing tree N content with urea or enhancing early defoliation with CuEDTA.

The authors concluded that spraying trees with a combination of urea and CuEDTA with phosphonate- containing fungicides in early autumn can be of benefit for early harvesting and preventing the contamination and/or infection of P. syringae in the field or storage. "Spraying pear trees with a combination of urea and CuEDTA after terminal buds have set in early autumn can benefit nursery operators because the pathogen is less active in warm dry environments and the trees are better able to heal wounds caused by defoliation or chemical treatments," they noted.


Story Source:

The above story is based on materials provided by American Society for Horticultural Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Laywisadkul, C. Scagel, L. Fuchigami and R. Linderman. Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae. HortTechnology, 20: 331-342 (2010) [link]

Cite This Page:

American Society for Horticultural Science. "Solutions to common pear fungal disease." ScienceDaily. ScienceDaily, 28 December 2010. <www.sciencedaily.com/releases/2010/12/101228180904.htm>.
American Society for Horticultural Science. (2010, December 28). Solutions to common pear fungal disease. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2010/12/101228180904.htm
American Society for Horticultural Science. "Solutions to common pear fungal disease." ScienceDaily. www.sciencedaily.com/releases/2010/12/101228180904.htm (accessed September 23, 2014).

Share This



More Plants & Animals News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Ice Age Wooly Mammoth Remains for Sale

Raw: Ice Age Wooly Mammoth Remains for Sale

AP (Sep. 23, 2014) A rare, well-preserved skeleton of a woolly mammoth is going on sale at Summers Place Auctions hope the 11.5-foot tall, almost intact specimen will fetch between $245,000 to $409,000. (Sept. 23) Video provided by AP
Powered by NewsLook.com
Fox Bites Conn. Student And School Staffers In Rare Attack

Fox Bites Conn. Student And School Staffers In Rare Attack

Newsy (Sep. 23, 2014) A fox attacked a second-grade boy at a Connecticut elementary school Monday. It also attacked two school staff members and a woman and her dog. Video provided by Newsy
Powered by NewsLook.com
Will Living Glue Be A Thing?

Will Living Glue Be A Thing?

Newsy (Sep. 23, 2014) Using proteins derived from mussels, engineers at MIT have made a supersticky underwater adhesive. They're now looking to make "living glue." Video provided by Newsy
Powered by NewsLook.com
Raw: Tiger Kills Man at India Zoo

Raw: Tiger Kills Man at India Zoo

AP (Sep. 23, 2014) A white tiger killed a young man who climbed over a fence at the New Delhi zoo and jumped into the animal's enclosure on Tuesday, a spokesman said. (Sept. 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins