Section in annual growth cycle the grapevine after blossom (see also under BBCH Code ). The fertilized female ovaries of the flowers develop into berries. This occurs in the northern hemisphere from June to July and in the southern hemisphere from December to January. The amount of berries is from the vine dependent. As a rule, about one third (e.g. Chasselas and Riesling) to a maximum of two thirds (e.g. Silvaner) of the individual flowers are fertilized. A berry contains up to five (rarely six) grape seeds that are used as seeds for the breeding new grape varieties can be used by sowing and selection.
Due to unfavorable environmental conditions such as frost (Late frost), diseases and pests or infections caused by virus bad fruit set can occur. Then the unfertilized or insufficiently self-fertilized ovules no longer mature into vine seeds. The non-fertilized flowers Verrieseln (French coulure), which means that after flowering they simply fall off or atrophy into small, fresh, seedless berries ( millerandage, French Millerandage).
In the berry development phase I (cell division phase) the first phase of berry thickness growth takes place. Depending on the variety and vintage, it extends over a period of 5 to 6 weeks. The condition of the fully grown and hiding the still hard and acidic berries is called closing of grapes (Picture right). In the berry development phase II (suspension phase = standstill) there is a growth stop purely externally. In this phase, the construction or dismantling of the acids to a certain value. The duration is very dependent on the variety, from a few days to three or even four weeks for Riesling. The next development step after these two phases is the berry development phase III; see under veraison (Maturity onset). A list of keywords specific to the grape variety can be found at grapevine contain.