Content tagged "apple disease"

Apple Tree Viruses

Apples Updated: November 26, 2014

Virus diseases cause economic losses through lower yields and reduced quality of apples and apple products. In general, virus diseases in perennial crop...

Fire Blight of Apple

Apples Updated: August 17, 2013

Figure 1. Blossom cluster and adjacent shoot with fire blight. (Alan R. Biggs, West Virginia University)Fire blight is a destructive bacterial disease of...

Apple Scab

Apples Updated: August 17, 2013

Apple scab is a fungus disease caused by Venturia inaequalis. It is of major economic importance and, if not controlled, can cause extensive losses (70% or...

Sooty Blotch and Flyspeck in Apple

Apples Updated: August 17, 2013

Sooty blotch and flyspeck are surface blemish diseases caused by fungi that commonly appear together on apple or pear in late summer and fall. Although these...

Cedar-Apple Rust

Apples Updated: August 17, 2013

Figure 1. Cedar-apple rust gall on eastern red cedar showing thoroughly wetted, gelatinous spore-bearing structures. (Alan R. Biggs, West Virginia...

Quince Rust of Apple

Apples Updated: August 17, 2013

Figure 1. Quince rust often forms orange tubes for spore dissemination. Photo: Alan R. Biggs, West Virginia University.Quince rust is a fungus disease caused...

Black Pox of Apple

Apples Updated: November 13, 2012

Black pox is a fungus disease caused by Helminthosporium papulosum. It is considered to be of minor economic importance. When it occurs, the disease can...

Powdery Mildew on Apple

Apples Updated: November 07, 2012

Powdery mildew on apple is a fungus disease caused by Podosphaera leucotricha. It can be a persistent disease of susceptible apple cultivars wherever apples...

Table of Apple Rootstock Susceptibility to Phytophthora spp.

Apples Updated: November 07, 2012

Apple Phytophthora root, crown, or collar rot has caused extensive death of apple trees in many eastern orchards during the past two decades. It often occurs...

What scab-resistant apple cultivars are resistant or susceptible to other diseases?

Apples Updated: September 03, 2011

All scab-resistant cultivars vary in their susceptibility to other early-season diseases; and all are susceptible to the summer diseases. See Table of Apple...

Apple Union Necrosis and Decline

Apples Updated: August 30, 2011

Apple union necrosis and decline (AUND) is caused by tomato ringspot virus (TmRSV). TmRSV also causes disease in other fruit trees (Prunus stem pitting of...

Bitter Rot of Apple

Apples Updated: August 30, 2011

Bitter rot is a fungus disease that causes fruit rot during the summer and preharvest period. The bitter rot fungi are almost worldwide in distribution and...

Blister Spot of Apple

Apples Updated: August 30, 2011

Blister spot is a bacterial disease of apple fruit caused by Pseudomonas syringae pv. papulans. This disease is of economic importance mainly on the cultivar...

Blue Mold on Apple

Apples Updated: August 30, 2011

Blue mold is a fungus disease caused by Penicillium expansum. It is the most economically important post-harvest decay of stored apples in the United States....

Brooks Spot on Apple

Apples Updated: August 30, 2011

Brooks spot is a fungus disease caused by Mycosphaerella pomi. It is a minor disease that occurs throughout the northeastern and mid-Atlantic apple growing...

Table of Juniper, Hawthorn, and Crab Apple Resistant to Rust Diseases

Apples Updated: August 30, 2011

 Cedar-apple rust is a fungus disease of apple and cedar and spends parts of its life cycle on each host. It is caused by Gymnosporangium...

Table of Apple Cultivar Fire Blight Susceptibility

Apples Updated: August 30, 2011

Fire blight is a destructive bacterial disease of apples and pears that kills blossoms, shoots, limbs, and, sometimes, entire trees. The disease is generally...

'Golden Delicious' Necrotic Leaf Blotch in Apple Trees

Apples Updated: August 30, 2011

Necrotic leaf blotch (NLB) is a physiological disorder whose occurrence is related to air temperature, light intensity, and soil moisture. The cause of NLB...

Nectria Twig Blight of Apple

Apples Updated: August 29, 2011

Nectria twig blight is a fungus disease that results in dieback of apple twigs. It is caused by the fungus Nectria cinnabarina.Recognition of the disease is...

Table of Apple Cultivar Susceptibility to Powdery Mildew

Apples Updated: August 29, 2011

Powdery mildew on apple is a fungus disease caused by Podosphaera leucotricha. It can be a persistent disease of susceptible apple cultivars wherever apples...

Phytophthora Root, Crown, and Collar Rot of Apple

Apples Updated: August 29, 2011

Crown or collar rot has caused extensive death of apple trees in many eastern orchards during the past two decades. It often occurs on trees between 3 and 8...

White Rot of Apple

Apples Updated: August 28, 2011

White rot is often referred to as Botryosphaeria rot or Bot rot and is caused by Botryosphaeria dothidea, a serious fungal pathogen of apple wood and fruit....

Burr Knots on Apple Trees

Apples Updated: August 23, 2011

Burr knots are root initials that appear on the aboveground portion of the apple tree trunk. Some rootstocks, such as M.7, M.9, M.26, MM.106, and MM.111, are...

Nectria Canker of Apple

Apples Updated: August 22, 2011

Nectria canker is a fungus disease caused by Nectria galligena. Occasionally, it is found on apple nursery stock shipped into the eastern United States;...

Thread Blight of Apple

Apples Updated: August 22, 2011

Thread blight is a fungus disease caused by Corticium stevensii. Primarily, the disease is a problem in poorly managed orchards in the southeastern United...

Connect with us

  • Twitter
  • Facebook
  • YouTube
  • Pinterest
  • Google+

Welcome

This is where you can find research-based information from America's land-grant universities enabled by eXtension.org

LOCATE

Latest Tweets

USDA / NIFA

This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.