Black rot is a fungus disease that can cause serious losses in apple orchards, especially in warm, humid areas. Three forms of the disease can occur:
Read more and see images in this article, Black Rot of Apple.…
The primary function of a windbreak is to reduce wind speed around areas in need of protection. If you are interested in having multiple species in your windbreak, apples might be a good choice.
Results from a number of apple rootstock trials in different regions of North America indicate that some rootstocks can influence fruit size. Trees on M.7, G.16, and M.26 generally produce smaller fruit than trees on M.9. Most other tested rootstocks produce fruit slightly smaller than M.9. Although experiments have not been performed to compare fruit size from trees grown on semi-dwarf or non-dwarfing rootstocks, orchard observations indicate that fruit produced by trees on M.9 are larger than fruit produced by …
Quince rust is a fungus disease caused by Gymnosporangium clavipes. The fungus infects fruit, but not leaves, of most apple cultivars. It infects both leaves and fruit of hawthorn. Typically, an infection on apple fruit shows up first as a slightly raised purplish area on the calyx end of the fruit. On mature fruit, the lesion is sunken and dark green or purple. Usually, the entire calyx end of the fruit is involved, and the flesh is deformed to …
Southern blight is caused by the fungus Sclerotium rolfsii. The disease is a problem primarily in the Piedmont apple-growing region in the southeastern United States. S. rolfsii is a widespread pathogen that affects several hundred plant species. For more information, read this article on Southern Blight in Apple Trees.
Answer provided by Alan R. Biggs, West Virginia University.…
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 by Gymnosporangium clavipes. The fungus infects fruit, but not leaves, of most apple cultivars. It infects both leaves and fruit of hawthorn.
Typically, an infection on apple fruit shows up first as a slightly raised purplish area on the calyx end of the fruit. On mature fruit, the lesion is sunken and dark green or purple …
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 juniperi-virginianae. The fungus can infect leaves and fruit of most cultivars in the eastern region. A notable exception is ‘Delicious’, which is nearly immune. For more information, see this article on Cedar-Apple Rust.
Answer provided by Alan R. Biggs, West Virginia University.…
White root rot, caused by the fungus Scytinostroma galactinum (formerly Corticium galactinum), has been known as a parasite of apple trees for many years and is widely distributed (Canada to Texas and westward to the Pacific Coast, Europe, West Indies, and Japan). It is found in both bearing and non-bearing apple orchards. Other hosts include a wide variety of woody plants, ornamental shrubs, and herbaceous perennials, including white pine, ash, peach, blackberry, dewberry, Japanese wineberry, dogwood, sumac, white campion, …
Apple mosaic virus is one of the oldest known and most widespread apple viruses. The same virus can cause line pattern symptoms in plum and rose mosaic disease. Apple mosaic virus is related to Prunus necrotic ringspot virus. Apple trees infected with apple mosaic virus develop pale to bright cream spots on spring leaves as they expand. These spots may become necrotic after exposure to summer sun and heat. Most commercial cultivars are affected but vary in severity of symptoms. …
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 cause an especially economically important disease in the southern areas of the United States. Outbreaks can occur rapidly, and losses can be severe, especially under prolonged warm, wet weather. Several host species can be affected. On peach and nectarine, the same fungus causes a disease known as anthracnose, and on grape, it causes ripe …
