LAWS OF BLOOM PHENOLOGY BY APPLE

Over the past two decades observations have been made on more than 250 apple cultivars, enabling us to reveal some important bloom phenological laws.
For apple, which requires cross-pollination, these laws can be utilized very effectively to classify cultivar-combinations which bloom together, and can be used to create an effective pollination system.

We have classified and systematized the factors affecting bloom time.
The relative succession order at the beginning of bloom is not permanent or constant even at one location.
The establishment of a relative succession order for one location with a high degree of probability requires at least ten years of observation.
Besides temperature, the ratio of flowers on the long shoots plays an important role during blooming.
The tendency for blooming on long shoots is cultivar specific and is affected to a great extent by the age and the vigor of the trees.

The cultivars have been placed into 4 blooming groups.
Placing cultivars into groups requires at least five years of observation.
The flowers of apple cultivars are protogynous.
The size of the dichogamy varies by year.
This happens because the receptivity of the stigmas and pollen dehiscence are affected differently by temperature during bloom.

VII International Symposium on Pollination

M. Soltész

blooming group, cross-pollination, dichogamy, joint blooming, relative bloom time

https://doi.org/10.17660/ActaHortic.1997.437.61