What is pollination?
Pollination is just transfer of pollen from the anther of the flower to the stigma of same or another flower. In nature pollination is mainly done by insects (mainly bees). These insects crawl into the middle of the flower where they pick up the pollen grains from the anther and then further visiting another flower they deposit pollen on the stigma. This is how pollination occurs.
Pollination in apple trees
Pollination is the most critical event in the production of apples. Excess fruits can be thinned, but there is no way to set more fruits after the flowering period have completed. All apple trees need to be pollinated to produce apple fruit. In Himachal Pradesh lesser production of apples is due to lack of pollination. For efficient pollination at least three polliniser are needed. In lower altitudes minimum 33% pollinating varieties should be present. In higher altitudes 25% pollinating varieties are sufficient.
What is self and cross pollination?
Self pollination is a type of pollination which occurs in a single plant in two ways i.e. within the same flower or genetically similar flower. In self pollination pollen grain can be transferred even in closed flower and no external agency (like bees) is required.
Cross Pollination is a type of pollination in which pollen grains are transferred from the anther of a flower to the stigma of another flower of same or different variety. For cross pollination external agents are essential for carrying the pollen grains.
AGENTS OF POLLINATION
Broadly there are types of pollinators—
- Abiotic agents (non living)
- Biotic agents (living)
Abiotic pollination is done either by air or by water. In abiotic pollination the pollen grains are released by wind until it reaches a stigma.
Biotic pollinators refer to various insects which help in transferring the pollen grains from the anthers to the stigma of different flowers. Biotic pollinators include honey bees, diptera, hymenoptera and thysanoptera.
Points to remember
- For cross pollination it is essential to place bee hives in the orchard,
- Pollinating varieties should be near to the delicious varieties,
- Pollinating and main varieties should have synchronized flowering (at same time)
- Do not spray pesticides which are toxic to bees and other friendly insects like carbryl etc.
- Pollinating varieties used should have good commercial value.
Pollinating Apple Varieties
- Tydeman’s Early,
- Golden delicious,
- Red gold,
- Granny Smith,
- Gale gala and other gala group,
- Ginger gold,
- Pink lady,
- Winter banana.