Apple is basically a fruit of the colder areas and most popular fruit in America. However, the situation is changing now as fruit scientists have made apple cultivation possible in other areas too. This means that the goal of many a gardener to have an apple tree of their own. In India, the apple trees are growing not only in places like Delhi and Chandigarh, but also in tropical parts like Karnataka and Kerala.
In winter, complex physiological changes take place within the trees and they shed their leaves and stop growing. This period of inactivity is called ‘dormancy’ and the shedding trees are called deciduous trees. These trees need to be exposed for a certain duration (in hours) at a temperature below 45°F or 7°C. Only then their dormancy will break and the spring growth will restart. This duration of ‘chilling hours’ varies from one variety to another between 150 and 1500.
Anna: This variety is from Ein Shemer kibbutz in Israel. It was bred by Abba Stein in the 1950s. Anna requires only 300 hours of chilling and can therefore be grown in the whole of Himachal Pradesh. Anna fruits look like the Golden Delicious variety.
Hariman or HRMN 99: This is a variety from Himachal Pradesh. It was noticed by a Bilaspur farmer, Hariman Sharma. Fruits of HRMN 99 are green or greenish yellow. These ripen in mid – June.
Dorsett Golden: This apple was noticed by Irene Dorsett in the Bahamas. It needs only 150 chilling hours and thus can grow nearly at every place. It also looks like Golden Delicious.
Apples can also be cultivated in a tropical climate where there is no winter and the minimum temperature does not fall below 12°C. To achieve this objective, plants are lifted from nurseries in Himachal Pradesh in mid-February when they have met their full chilling requirement. These are then airlifted and planted at their new destination. As these plants have already met their chilling requirement at the nursery, so they immediately start growing.
The apples from Himachal Pradesh, Punjab and Haryana begin ripening a month earlier in June.