This measure (also Blattschnitt, summer cut) in the vineyard is possibly carried out several times. There will be a limited number of Scroll removed from the grape zone. The measure is recommended for short-leaved, dense foliage grape varieties with compact, dichtbeerigen Grapes and skins, for example Pinot Noir. Gewurztraminer. Kerner. Müller-Thurgau and Scheurebe (Seedling 88). The defoliation promotes the air circulation in the grape zone, so that the grapes dry after rain much faster. As a result, the ripening fruit before premature Botrytis protected. You start defoliation two to three weeks after blossom, but not too many leaves should be removed, because until the veraison (Beginning of ripening), the green berries are still strong sunburn endangered.
A shading by dense foliage protects very effectively against intense sunshine and thereby triggered grapes wilt, In August to mid-September, however, individual leaves are also removed, thereby improving the air and light conditions. This also works bunch rot and also leads to better dye formation in red wine grapes. Exfoliation is already carried out by machine in large wineries today. However, do not allow too much defoliation, because healthy leaves in sufficient numbers are for photosynthesis and sugar production important.
An unfavorable relationship between fruit and foliage shows in reduced content glucose (Glucose) and phenols in the grape and possibly worsens the wine quality. In addition, external circumstances such as hail or frost, Pests like locusts or vine diseases such as wrong mildew during the growth cycle lead to unexpected foliage loss. Of the Rebstock responds to too much foliage loss with the expulsion of the epicormic shoot (Secondary shoots). First, carbohydrate reserves are used up. Extreme, repeated defoliation can lead to death.
At the end of the vegetation cycle, when the vine has filled its reserve of carbohydrates in late autumn, it does leaf fall, This natural process usually takes place with the first frost. The complete defoliation by chemical means shortly before vintage to facilitate a mechanical harvesting has proved to be ineffective. Because after the harvest to the natural leaf fall, the foliage wall foliage wall still contributes significantly to the good maturation of the annual shoots and for the storage of reserve materials in the vine at. See also below pruning and a list of all activities under Weingarten Care,