Powdery mildew on apple is a fungus disease caused by Podosphaera leucotricha. It can be a persistent disease of susceptible apple cultivars wherever apples are grown. It is the only fungal apple disease that is capable of infecting without wetting from rain or dew. Mildew severity and the need for control measures are related to cultivar susceptibility and intended fruit market. For more information and images, read this article on Powdery Mildew on apple trees.
Answer provided by Alan …
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 diseases may shorten the storage life of fruit due to increased water loss, they do not cause decay, and losses are attributed to unacceptable appearance. During wet growing seasons, losses of 25% or more are commonly found even in orchards treated with fungicides. Many fungi are involved in this complex of pathogens, including Peltaster …
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 regions of the United States and occasionally as far west as Iowa. Some of the more susceptible common commercial cultivars include ‘Jonathan’, ‘Golden Delicious’, ‘Stayman’, ‘Grimes Golden’, and ‘Rome Beauty’. Read more about Brooks Spot in Apple.
Answer provided by Alan R. Biggs, West Virginia University.…
Fire blight is a destructive bacterial disease of apples and pears that kills blossoms, shoots, limbs, and, sometimes, entire trees. The disease is generally common throughout the United States wherever apples are grown, although outbreaks are typically very erratic, causing severe losses in some orchards in some years and little or no significant damage in others. This erratic occurrence is attributed to differences in the availability of overwintering inoculum, the specific requirements governing infection, variations in specific local weather conditions, …
You can plant seeds from your apple, but the resulting fruit from that seedling will not be exactly like the apple parent. Most apple seeds are formed when pollen from one apple cultivar pollinates the flower of another cultivar. This results in the combination of two different genetic parents and results in an offspring (seed) that has a different genetic code. The resulting seed and potential tree will have characteristics of both the pollen parent and the flowering parent. Therefore, …
Apples do not come true from seed, so when we plant apple seeds, the plants that result are not the cultivar that we obtained the seeds from. If we take six seeds from an apple and plant them, the resulting trees will produce fruit that is different from fruit on the parent tree, and the seedlings will be different from each other. To maintain a cultivar, we have to propagate the tree vegetatively. Since apple cuttings are difficult to root, …
Budding is often used because a single scion bud is inserted into the rootstock to produce a new tree. Also, with budding, many trees can be produced from a stick of bud wood that has different sized buds.
In contrast, a piece of scion wood with two buds is used in grafting, and the diameter of the rootstock and the scion piece must match precisely to form a union. Thus, fewer trees can be propagated by grafting as compared to …
Heavy soils are those that contain more clay particles relative to sand and silt components. The high clay content causes the soils to be less friable, making them “sticky,” and more dense, thus making them hard to work with. They often remain cold and wet in spring and need grit or coarse organic material to admit air and help roots remain healthy. Because of their tendency to be cold and wet for longer periods than lighter soils, there is an …
Consider the relative susceptibilities of the scion and rootstock to fire blight when establishing new orchards. There is considerable variation among apple cultivars (and pear cultivars) in susceptibility to fire blight, although none are immune. Some cultivar/rootstock combinations are so susceptible to fire blight that investments in these combinations are extremely high risk. In the eastern United States, ‘Gala’ on M.26 is an example of a high-risk combination. For more information, read this article on Fire Blight of Apple.…
Apple seeds that are planted do not produce a replica of the type of fruit that was planted; therefore, trees must be propagated by vegetative means such as budding or grafting. Typically, they are grafted onto a rootstock, which is just another apple selected for certain characteristics, such as dwarfing and/or disease resistance. (But not eating quality!) The rootstock provides many benefits to the finished tree. The most important one is ultimate tree size control.
In apples, tree size has …