The apple tree (Malus domestica) is a small, deciduous tree in the rose family and is one of the most widely cultivated fruit trees. Its flowers are white with a pink tinge and blossom in the spring. The apple fruit can exceed three inches in diameter and ripens in autumn. Apple trees originated in Central Asia, and were one of the first trees to be cultivated. They were brought to North America by the first colonists in the 1600s and are currently one of the most important fruit crops in the United States.
Malic acidMalic acid is the component in an apple that gives it a sour taste. Apples have a wide range of malic acid content, and this characteristic is an important consideration in developing new varieties of apples.
GraftingGrafting is a process in which a section of a stem with leaf buds is attached to the stock of a different tree. Apple trees are commonly reproduced by grafting in order for them to breed true.
University of Minnesota Extension provides a more detailed description of grafting and the reasons for performing this procedure.
CarpelA carpel is the structure of a flower that contains the incipient seeds. If the ovary can be divided into segments, each segment is a carpel. An apple consists of five carpels.
PomeA pome is an accessory fruit composed of five or more carpels in which the outermost layer of fruit forms an inconspicuous layer. The fruit of an apple tree is a type of pome.
The University of Georgia has a glossary of terms related to fruit crops, including pome.
CultivarA cultivar is a cultivated variety of a plant that retains a specific set of characteristics when it is cultivated. Apple trees have an extremely large number of cultivars.
The California Backyard Orchard provides a glossary of terms that are commonly used in growing fruit trees, such as cultivar.
Apple scabApple scab is a common fungal disease of apples that usually affects the fruit and leaves. Resistance to Apple scab is a common consideration when selecting which variety of apples to grow.
Fruitful Land provides a detailed description of Apple scab, including photographs.