What Are Basal Leaves on Grapes?

Description

• Basal leaves are the leaves that center around the base of a plant's stem, composing the first five or so nodes of the plant. Upon close examination, these leaves may appear different than other leaves growing on the plant. They tend to be less productive in their fruit output because they are more shaded from the sun than other leaves, and are at a different growth stage. Sometimes nutrient deficiency, such as magnesium deficiency, appears more clearly on these leaves.

Basal Leaf Removal

• Basal leaf removal has become a popular practice by wine grape growers, who believe that removing these low-lying leaves prevents disease and boosts productivity. Removing these extra leaves, which are otherwise unproductive, helps maximize light exposure to buds. Cultivators remove between 50 and 100 percent of basal leaves from the low nodes of a grape vine, sometimes leaving just a few at each node. The process is often conducted just as fruit is setting in order to allow the fruit to acclimate to sun exposure so they are ready to bear the following year.

Benefits of Removal

• In addition to boosting sunlight to productive, fruiting parts of the plant, removing basal leaves protects grapevines from mildew and other diseases. Powdery mildew, a fungal disease, can wreak significant damage to grape vines. Studies indicate that removing basal leaves reduces the effects of rot and mildew on grapes, perhaps by improving fungicide spray coverage. Pests like the grape leafhopper lay their eggs on basal leaves, so removing them can help you steer clear of the harmful insects.

Pruning

• Pruning is essential to any productive grapevine. Basal buds, which are buds on the lower leaves of the plant, will not produce well unless shading is minimized through basal bud removal. Removing unnecessary foliage improves air flow and allows the cultivator to apply horticultural sprays evenly on the canopy. It improves fruit quality by maximizing sunlight exposure.