Some cultivars of apple are under patent. If the patent is still applicable, then you must contact the nursery (or whoever holds the patent) and pay the royalty for each tree you propagate. Failure to do so could lead to criminal penalties, a monetary judgment (and/or fine), and destruction of the trees you propagated. Apple cultivars that are part of an exclusive club or licensing agreement are also illegal to propagate, and there usually is no avenue for a “non-club …
What is black rot, and how do I identify and manage the disease on apple trees?
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:
- a fruit rot, which causes fruit to become unmarketable;
- a leaf spot known as frogeye leaf spot which, if severe, can result in defoliation which weakens the tree; and
- a limb canker which can girdle and eventually kill entire branches.
Read more and see images in this article, Black Rot of Apple.…
Can I grow apple trees in my windbreak?
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.
- Locate the apple trees in interior or wind-sheltered rows as their tolerance to wind is not as great as that of other species.
- Place the apple trees closer than in a typical orchard, and plan for a reduced fruit yield, particularly if the windbreak plantings are
How do rootstocks affect apple fruit size?
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 …
What is quince rust, and how do I identify and manage the disease on apple trees?
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 …
I have a 'Gala' apple tree. Would planting a 'Granny Smith' tree in my yard serve as a pollinator for the other?
Yes, ‘Granny Smith” would be a good choice. If you can’t find a ‘Granny Smith’ tree, then a ‘Mollies Delicious’ would work well. To see a pollination chart for apple varieties, refer to this article on Pollination of Fruit Trees.…
What are the disease-resistant apple cultivars recommended for Wisconsin?
The following are some of the cultivars that will grow well in Wisconsin:
• Redfree: This is an early season, medium-sized, attractive red apple. You can store these apples up to 30 days.
• Prima: Prima produces medium to large fruit, red blushed on yellow skin. Mild, juicy, white flesh matures a week before McIntosh. You can store this apple for one to two months.
• Priscilla: This is a medium to large apple if you thin trees adequately after …
What causes the yellow leaf spots that later develop a brown center on my apple leaves?
This a fungal disease called cedar-apple rust. Cedar-apple rust is a common disease of apple and crabapple. The fungus that causes the disease, Gymnosporangium juniperi-virginianae, is unusual because it must spend a phase of its life cycle as a parasite on Juniperus species, such as red cedar or ornamental junipers. Control: Grow resistant apple or crabapple varieties. Apple varieties that normally show good to excellent resistance to cedar-apple rust include ‘Red Delicious’, ‘McIntosh’, ‘Arkansas Black’, ‘Winesap’, ‘Mollies Delicious’, ‘Spartan’, …
Which rootstocks are winter hardy?
Rootstocks can affect the development of cold hardiness in apple trees, but this is a complex trait, and it may depend on what time of the winter with which one is concerned. Some rootstocks, such as Robusta 5, can cause a tree to harden early in the winter, and these trees are very cold tolerant during the early winter. Some rootstocks, such as Robusta 5, that induce early cold hardiness also lose their hardiness early in the winter in response …
What experimental rootstocks for apples are being looked at in the U.S.?
Many apple rootstocks are being evaluated for potential use in the United States by the NC-140 Multi-State Research Committee. These rootstocks have come from breeding programs in the United States (CG, G), Great Britain (M), Germany (PiAu and Supporter), Poland (P), Czech Republic (J-TE), Japan (JM), and Russia (B). Specific rootstocks that are currently under evaluation in NC-140 plantings include the following: B.9, B.10, B.7-3-150, B.7-20-21, B.67-5-32, B.64-194, B.70-6-8, B.70-20-20, B.71-7-22, G.11, G.16, G.41, G.202, G.935, CG.2034, CG.3001, CG.4003, …