Winegrowers Supplies
- Development Stages of the Vine
In 1977, Dr K W Eichhorn and Dr H Lorenz, classified grapevine development in 47 stages, which occur between the first stage 'winter dormancy' and the last stage 'end of leaf fall'. The dates when these stages occur are dependent on the environment in which the vineyard is planted. Knowing the stage of your grapes during the growing season has many useful applications.
If problems arise during the growing season, a grape specialist helping solve your problem will need to know what stage of development your grapes were at when the problem manifested. Communicating this information helps pin-point what problems would most often exist during this stage of grape development.
Culture and chemical applications are often prescribed at certain stages of grape development. For example, bunch thinning/removal is sometimes performed when the berries are pea-size or smaller. Often you will see chemical labels refer to certain stages when chemicals should or should not be applied such as pre-flowering, flowering, and bunch closure. For the chemicals to be effective in controlling pests, chemicals should be applied at stages as specified on the label.
The stages published originally by Dr K W Eichhorn and Dr H Lorenz, in 1977, were:-
01 Winter dormancy
02
Bud swelling
03
Wooly bud: the brown wool is clearly visible
05
Bud burst: the first green (or pink) of the shoot is visible
07
First leaf unfolds and extends from the shoot
09
Two to three leaves unfold
12
Five to six leaves unfold: the inflorescences are clearly visible
15
Inflorescences get larger: individual flower-clusters are tightly packed
17
Inflorescences are fully developed: the individual clusters are extended
19
Flowering begins: the first flower caps free themselves
21
Full flowering: 25% of the flower caps have been shed
23
Full flowering: 50% of the flower caps have been shed
25 Post-flowering: 80%
of the flower caps have been shed
27
Fruit set: fruit buds get larger, cleaning up of the berries is concluded
29
Berries are the size of grain, bunches begin to go downwards
31
Berries are the size of peas, bunches hang down
33
Beginning of the conclusion of bunch formation
35
Ripening begins: berries become translucent, begin to lose their colour
38
Berries are ripe for harvesting
41
Post-harvest: wood-ripening is concluded
43
Start of leaf fall
47
Finish of leaf fall
There is now a Modified Eichhorn-Lorenz system:-