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Peach Tree Problems #246147

Asked May 21, 2015, 11:06 AM EDT

We have experienced die off in our peach tree orchards. I will attach some photos. I dont believe the first two pictures are the same problem as the second two pictures. First two look like the same problem and second two look like same problem. Problem 1) the leaves have red hole shots in them and the foliage is not near as abundant on healthier trees. Problem 2) large trees have died off since pruning in Jan/Feb. You can see one small scaffold limb that is still alive in the last picture whereas the rest of the tree is completely dead. This has occured since pruning and seems to be in same general area of the orchard where other trees have died last year. Any help is greatly appreciated. Thanks

Van Zandt County Texas

Expert Response

Peach growing information

http://aggie-horticulture.tamu.edu/fruit-nut/files/2015/04/peaches_2015.pdf

Spray schedule is here:
https://insects.tamu.edu/extension/bulletins/b-5041.html

Peach crop information is found at this location

http://aggie-horticulture.tamu.edu/smallacreage/crops-guides/fruits-nuts/peaches/

pest control

http://amarillo.tamu.edu/files/2010/11/PestsFruitTrees.pdf

Fruit tree spray schedule

https://insects.tamu.edu/extension/bulletins/b-5041.html

Contact your county agent for more help. There are many peach orchards in Gillespie County and the county agent usually holds short courses about fruit crops.

http://gillespie.agrilife.org/

Jim Kamas is the Horticulture CEA but is on special assignment with the Texas Viticulture & Fruit Lab. Jim can be reached through our office for special needs related to fruit tree management.

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An Ask Extension Expert Replied May 21, 2015, 12:46 PM EDT
Not helpful at all. I have all of this information and much more in depth. I am trying to narrow the die off and red shot holes down to the cause. Not some generic auto response. Sorry to waste our time.
The Question Asker Replied May 21, 2015, 1:09 PM EDT
Never a waste of time. I never know how much knowledge the person asking has.
Please contact Jim Kamas. Jim is Texas A&M Extension fruit tree specialist. His office is in Fredericksburg, TX,<personal data hidden> or <personal data hidden>

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Email: <personal data hidden>

The tree die off may be cotton root rot since you say it is in a local area in the orchard. But please email Jim Kamas the pictures and ask him. One sure symptom is when the die dies, the brown leaves stay on but since happen during the winter hard to use this diagnostic symptom. Did the trees that died the year before die in winter after pruning or during the summer.

Did you use a weed and feed fertilizer? I have seen atrazine do this.

Shot Hole Disease

Pathogen: Wilsonomyces carpophilus

SYMPTOMS AND SIGNS

The main symptoms of shot hole on peach occur on twigs and buds, but fruit lesions may develop when spring weather is wet. Twig symptoms first appear as small, purplish black spots. These turn brown as they enlarge, often having a light center with a purplish brown margin. Tiny, dark brown bumps develop at the center of each lesion. These bumps are spore-forming structures called sporodochia and are easily seen with a hand lens. When buds are affected, the scales turn dark brown or black and the buds may be covered with a shiny layer of exuded gum. Buds killed by bacterial blast have a similar appearance but tend to be much blacker, and nearby foliage of the affected shoot is wilted. Shot hole can be distinguished on peach by the presence of tan twig lesions with dark margins, usually accompanied by profuse gumming.

Fruit and leaf symptoms look much like those of twig lesions. They are small spots, purplish at first, and turning light brown in the center as they enlarge. Sporodochia form in leaf lesions but not in fruit lesions. Leaf lesions may be surrounded by a light green or yellowish zone; in many cases the brown tissue in the center will fall out, leaving the "shot hole" that gives the disease its name.

COMMENTS ON THE DISEASE

Wilsonomyces carpophilus survives on infected twigs and buds. Spores are produced throughout winter and are spread by splashing rain and wind. The disease is favored by prolonged wetness in fall to mid-winter (twig blight). Summer rain or sprinkler irrigation encourages fruit infection. There is more infection low in the tree where fruit stay wet longer.

MANAGEMENT

Shot hole is managed primarily with fungicide treatments to protect buds and twigs from infection. In orchards where twig infections are prevalent, the efficacy of the dormant treatment can be improved by pruning out and destroying infected wood. If the orchard is sprinkler irrigated, be sure to angle sprinkler heads low enough to keep from wetting the canopy.

Organically Acceptable Methods
Treatment with Bordeaux mixture and some formulations of copper are acceptable for use in an organically certified orchard.

Chemical Control
In areas where orchards have a history of this disease, spray at leaf fall or from November 15 to December 1 before winter rains to protect against twig infections. This spray also helps control leaf curl.

If needed, make a spring application during bloom to prevent fruit and leaf infection. If weather is wet, look for fruiting structures in leaf lesions. If any are present, treat with a product, such as pyraclostrobin/boscalid, chlorothalonil, or azoxystrobin, that is used for both brown rot and shot hole control.

 

An Ask Extension Expert Replied May 21, 2015, 3:11 PM EDT

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