Apple Fruit Growing Cycle
The apple seed follows a lengthy process from the apple orchard to a delicious apple fruit. The apple fruit trees sleep in winter while carrying buds on their branches. Some of these buds have leaves within them, some other contain five flowers.
In spring or late winter when the weather gets warmer, the buds start unfolding on the end part of the small branches. Two types of buds grow on the apple tree: the vegetative buds that only yield shoots and leaves, and the mixed buds which yield shoots, leaves and flowers. Every flower bud of the apple tree yields five flowers.
The flower that opens first is named king flower and produces the largest apple fruit in comparison to other flowers. The other four flowers normally open about 48 hours later than the king flower. In order to result in apple fruits, the flowers need pollen which should come from flowers of another tree or different cultivar. This pollen is mostly carried by honey bees.
Some apple orchard owners keep beehives in their orchard especially when the apple trees are blossoming. Bees help the cross pollination of the apple tree. Although some apple tree kinds are available that are self-pollinating, but if these trees be cross-pollinated, the product will be greater. So cross pollination is needed for better results.
The apple flower is composed of several parts; in the following picture you can see the components of apple fruit flower (picture 1). Petals contain nectar and have an attractive scent which attracts bees.
While collecting nectar, bees take pollen with them. When bees go to the flower of another tree, they leave the pollen grains on the sticky stigma of the pistil of other flower. Then, the pollen particles sink to ovary by sending tubes down through the styles. The sperm, which is in pollen, passes through filament and goes to the ovules in the ovary. In this way, the ovules get fertilized and turn into seeds.
The ovary gradually grows and it constitutes the fleshy part of the apple fruit. By summer, the apple fruits gradually grow and get bigger and more colorful. Until autumn, the apples get ripen and ready to be picked.
Two weeks before the harvest time, the farmer cuts the food supply of the apple fruit, so the apple fruits get sweeter. Finally, apple fruits are harvested by hand.
Maturation and Harvest The maturity level of the apple fruit reveals the harvest time. If you don’t wait until the apple fruit get mature, the apples won’t have the perfect flavor and aroma. In contrast, if you harvest the product later than the appropriate time, the apple fruits get soft and the quality decreases.
So, the orchard owners are usually checking for the apple fruit maturity. They usually check for the color of fruit and firmness of the texture. They also test the starch breakdown patterns by some reaction on the diagonal parts of the apple fruit.
Apple varieties may have different harvesting times during a year, but generally apple fruits ripen in autumn between the beginning of august and the middle of the November.
The apple types that ripen in the summer are Golden Supreme, Gala, Transparent, McIntosh, Primate, Duchess, and Sweet Bough. Some apple types that ripen in autumn are Jonagold, Fuji, Golden Delicious, Chenango, Red Delicious, Wealthy, Gravenstein, Snow, McIntosh, and Blenheim.
The apples that yield crop in winter are Granny Smith, Winesap, Wagener, King, Swayzie, Tolman sweet, and Greening.
The weather condition also may have influences on the harvest time of the apple fruit. In places with warm days and cool nights, the apple fruit ripens sooner than places with warm and rainy days. To check the maturity of the apple fruit, some qualities should be checked.
These qualities are: skin color, firmness, seed, and amount of sugar. When apple fruit ripens, the color of apple skin and flesh changes , the taste gets less sour or acidic, the color of seeds becomes brown, the starch turns to sugars, the apple texture changes and becomes softer, and the smell quality improves based on the apple kind. The various apple cultivars vary in their yield.
Also, unpruned apple trees become very large and yield more apple fruits which make it more difficult to harvest. Considering the number of trees planted per unit surface area, a mature apple fruit tree may produce about 40-200 kg apples during a year. Although in poor years there may be no considerable product.
The dwarf sized trees usually produce about 10-80 kg apple fruit during a year. In harvest time, apples are picked by hand and use of three-point ladders that are specially designed for this purpose and can be used easily among the branches of the apple tree.
If the apple trees are pruned regularly, they won’t get very large, and it would be much easier to harvest the apple fruits. The apples are later packed and delivered to the market.
Storage After harvest, the apple crop is immediately taken to the market or stored for a long time. For long storage, the apple fruit should be picked about one week before it completely ripens. But, for short term consumption, the apple fruit should be picked when completely ripens. For commercial storage, the apple fruits are kept in chambers with controlled temperature for some months.
The atmosphere of the chambers is also controlled and helps delaying the apples ripening caused by ethylene.
Theses chambers also filter the air and contain carbon dioxide which prevents increasing the amount of the ethylene and consequently prevents quick apple fruit ripening.
When the fruit is taken out of the chambers or storage, the fruit continues the process of ripening. The best store temperature for apple fruit is 0.5°C.
Regarding home storage, most of the apple fruit varieties can be stored for about two weeks at the refrigerator with the temperature of about 3 degree °C (below 5 °C).
Some apple fruit types such as Fuji and Granny Smith have a longer storage life and can be stored for about one year in refrigerator.To be fresher and to extend the shelf life of apple fruits, it’s better to put them in a plastic bag or in the drawer.
Before storage, the rotten apples should be separated because they spoil the healthy apple fruits. Also, apples should be stored separate from other vegetables because in the process of ripening apples give off gas that spoils other vegetables.