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 August 2, 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 August 2, 2014).

Share This




More Plants & Animals News

Saturday, August 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pyrenees Orphan Bear Cub Gets Brand New Home

Pyrenees Orphan Bear Cub Gets Brand New Home

AFP (Aug. 1, 2014) The discovery of a bear cub in the Pyrenees mountains made headlines in April 2014. Despire several attempts to find the animal's mother, the cub remained alone. Now, the Pyrenees Conservation Foundation has constructed an enclosure. Duration: 00:31 Video provided by AFP
Powered by NewsLook.com
Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. Video provided by Newsy
Powered by NewsLook.com
Rare Whale Fossil Pulled from Calif. Backyard

Rare Whale Fossil Pulled from Calif. Backyard

AP (Aug. 1, 2014) A rare whale fossil has been pulled from a Southern California backyard. The 16- to 17-million-year-old baleen whale fossil is one of about 20 baleen whale fossils known to exist. (Aug. 1) 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:
from the past week

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