Armillaria root rot, also known as shoestring root rot, is a soilborne disease that can affect several fruit crops, but it is most common in the eastern United States on peach and apple trees. Its host range also includes numerous species of deciduous and evergreen trees, shrubs, and woody vines. The greatest prevalence of the disease is in orchards planted on newly cleared land in which the soils are sandy and well drained. In these locations, pieces of wood invaded …
What is black pox, and how do I identify and manage the disease?
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 affect apple bark, fruit, and foliage. It is more common from southern Virginia southward than in the northern mid-Atlantic region. The same fungus causes blister canker on pear. For more information, read this article on Black Pox of Apple.
Answer provided by Alan R. Biggs, West Virginia University.…
What is black root rot (dead man’s fingers), and how do I identify and manage the disease?
Black root rot, also called dead man’s fingers or Xylaria root rot, is occasionally observed on mature apple and cherry trees. Although trees of all ages can be infected, most trees that die from black root rot are at least 10 years old. Black root rot is caused by two species of the fungus Xylaria, X. mail and X. polymorpha, with the former being more common in the southern Appalachian states, and the latter more common in the eastern …
What is Nectria canker, and how do I identify and manage the disease on apple trees?
Nectria canker is a fungus disease caused by Nectria galligena. It is occasionally found on apple nursery stock shipped into the eastern United States. The economic effects of the disease in the eastern United States are minor. The fungus grows deep into the wood and kills new wound callus as it develops. This annual killing of successive layers of callus results in perennial, target-like, zonate cankers. Eventually the cankers girdle the tree, resulting in a dieback of infected limbs …
What is apple union necrosis and decline, and how do I identify and manage the disease?
Apple union necrosis and decline is caused by tomato ringspot virus, which also causes disease in other fruit trees, small fruits, and many herbaceous plants. Symptoms appear as infected trees reach bearing age. Bud break is often delayed in the spring, and leaves are small and sparse with a dull, pale green color. Terminal shoot growth is reduced, with shortened internodes. Infected trees flower heavily and set large numbers of small, highly colored fruit. Leaf discoloration and leaf drop occur …
How can I control insects and diseases on my apple tree?
Homeowners are often surprised at the damage pests can do to apples. It is not easy to grow apples as pretty as those seen in the grocery store. Several diseases and insects can damage apple trees. Besides spraying pesticides, other things can be done to reduce pest damage, but it is very difficult to grow quality apples without some kind of pesticide application schedule. Rake and destroy leaves in the fall to reduce damage from diseases that overwinter in infected …
What is the best way to tell when apples and pears are ripe?
Harvest time varies with individual tastes and locality. One may consider a fruit ripe, while another individual believes it is immature. However, fruit picked too soon does not store well and does not develop full flavor. Probably the most reliable index is the number of days after bloom: Red Delicious takes 135 to 155 days from full bloom to harvest, whereas Granny Smith takes 170 to 180 days from full bloom to harvest. Other factors to consider include seed maturity; …
I bought some Whitney crab apples for pickling. I ate one prior, and it was fine. After I did the pickling, I cut a few open and there was a brown ring around the core of the seeds. Do you know what might have caused this?
The brown flesh around the core may have been caused by a fungus such as Alternaria sp.that entered through the calyx early in the fruit’s development. The condition, called moldy core, often cannot be detected until the fruit is harvested and cut. Here is a note about moldy core from the University of Massachusetts Apple Team:
“Moldy Core: This disease causes a rot with visible fungal growth in the seed cavity and core of some apple cultivars, particularly Delicious …
What is the method to get apple trees to set fruit?
All varieties of apple trees require some cross-pollination for fruit set. Even though some varieties are listed as self-fruitful, they will set fruit more heavily and more regularly if they are cross-pollinated. For solid block plantings, select varieties such as spur-type ‘Winter Banana’, spur-type ‘Golden Delicious’, or flowering crabapples such as ‘Manchurian’ and ‘Snodrift’ for pollinizers. Place honeybees in apple orchards when the first blossoms open. For more information on managing fruit trees, see this article on Pollination of Tree …
What are some suggestions for growing apples successfully in Colorado?
Reliable varieties for this area are ‘Cox Orange’, ‘Red Delicious’, ‘Golden Delicious’, ‘McIntosh’, ‘Jonathan’, ‘Fameuse’, ‘Northwest Greening’, ‘Joyce’, ‘Wealthy’, ‘Lodi’, and ‘Haralson’. Select two different varieties for cross pollination and good fruit production. In most cases, planting semi-dwarf varieties rather than standard size trees will allow enough room for at least two different varieties in the landscape. For additional hints for growing apples successfully, see the Colorado PlantTalk script on Apples.…