For trees on size controlling rootstocks, the bud union should be 3 to 6 inches above the soil line. Remember that in some instances the tree can settle causing the bud union to become covered with soil. If the union is covered it may allow the scion to develop roots and the benefits of the size controlling rootstock could be lost. Conversely if the union is too high you may experience increased size control resulting in a smaller tree than …
What do apple rootstock leaves look like?
A general description of rootstock leaf characteristics does not exist, because each rootstock has leaves that are characteristic of that particular rootstock. Rootstock leaves, like cultivar leaves, can vary in size, shape, color, leaf margin serration, pubescence, petiole thickness, and petiole length. Also, they differ by the presence of stipules at the petiole base, and leaves may be flat or cupped. In general, the rootstock leaves will look different than the leaves on the scion cultivar, so one should be …
Will an apple tree grow differently if I plant the graft union high above the soil or close to the ground?
The planting depth is critical, especially for trees on dwarf or semi-dwarf rootstocks. When planting, dig the hole deep enough to allow the tree to be planted with the graft union 2 to 3 inches above the ground. If the tree is planted too deep and the graft union is below the ground level, the scion variety will form roots and the tree will become a standard-sized tree. Also, if the graft union is buried, the tree may send up …
Do trees planted on dwarfing rootstocks produce small apples?
Without question, a dwarfing rootstock can reduce vegetative growth, resulting in a tree with a smaller trunk, shorter height, narrower canopy, and lower root volume. These rootstocks, however, do not reduce size of leaves, flowers, or fruit. Nearly all NC-140 apple rootstock trials have evaluated rootstock effects on fruit size, and, in some cases, rootstock did in fact affect size. In no case was the relationship between the degree of dwarfing and fruit size such that the more dwarfing the …
What is apple scab, and how do I identify and manage the disease?
Apple scab is a fungus disease caused by Venturia inaequalis. It is of major economic importance and, if not controlled, the disease can cause extensive losses (70% or greater) where humid, cool weather occurs during the spring months. Losses result directly from fruit or pedicel infections or indirectly from repeated defoliation, which can reduce tree growth and yield. For more information, read this article on Apple Scab.
Answer provided by Alan R. Biggs, West Virginia University.…
Why can’t I plant seeds from my apple?
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, …
Why are rootstocks used for apple trees?
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, …
Why do nurseries use budding versus grafting?
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 …
What is bitter rot, and how do I identify and manage the disease?
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 …
What is blue mold, and how do I identify and manage the disease?
Blue mold is a fungus disease caused by Penicillium expansum. It is the most important postharvest decay of stored apples in the United States. The losses from this disease can be significant but can be substantially reduced by following proper sanitation and control measures. The fungus not only causes fruit decay but also produces the carcinogenic mycotoxin patulin. This toxin may rise to unacceptable levels in fruit destined for processing and may also result in off flavors. For more …