Life Cycle of the Grapevine

Grapevine refers to the plant, belonging to the genus Vitis of the family Vitaceae. In total, there are about 60 species of Vitis, of which the most commonly grown is Vitis vinifera. Grapevine is either deciduous or evergreen. The leaves are palmately lobed and arranged alternately. The fruit of this species is a true berry, known as grapes. Cultivated varieties of grapevine bear green, red or purple colored grapes. In case of wild variety, the berries are small and dark purple in color. Grapevine grows best in humid climatic conditions

Life Cycle of the Grapevine

Life cycle of the grapevine can be categorized under certain stages, depending upon the growth pattern of vitis plants. In fact, caring tips for grapevine are based on the season and growth of the plants. Understanding the annual life cycle is necessary for growing grapes, so as to take care of the plants for maximum harvest. The annual life cycle of grapevine begins after the dormant stage, duing early spring.

Bud Break
Sap concentration occurs after the plants have been pruned in dormancy, which is necessary for the development of buds. The newly developed buds are prone to frost damage, hence proper protection is necessary in case of frosting. Depending on the environmental conditions, new leaves develop within 3-4 weeks after the bud break in March. At this time, maximum food storage is done through photosynthesis.

Examine the onset of powdery mildew disease on the leaves and stems. If necessary, apply antifungal sprays to control the disease. In case, there is an extra shoot growth, remove by suckering without affecting the vine. This allows storing of maximum energy for the formation of flower clusters.

Flowering
Development of flower clusters usually occurs within 9-10 weeks after the bud break, in late May or early June. Flowering time may vary based on the vitis variety and climatic conditions of the region. Pollination of flowers is necessary for the formation of berries. Heavy rain or too hot temperature conditions may prevent pollination. Within a week or two, the flowers are pollinated, thus resulting in small berry development.

Fruit Set
The fertilized or pollinated flowers develop into small berries, while those unfertilized ones drop. Young grape berries should be protected from frosting (if occurs). Heavy watering should be done to prevent drying out of the berries. In this stage, the cells undergo division leading to enlargement of the berries. Thinning of the leaves and shoots should be done in order to give space to the berries. While doing so, insure that the fruits are not exposed directly to sun, as it may cause sun scald.

Veraison (Coloring)
The next stage in the life cycle of grapevine is veraison, which is characterized by softening and color development of berries. Berry softening is due to the accumulation of sugars. It can be considered as ripening stage of the grapevine. The berry color depends on the variety of the grapevine. For better coloration of the berries, many growers prefer to trim the canopy. Veraison usually falls in late July, about 45 days after fruit set.

Harvesting
Maturity of the berries varies depending on the variety of the vine. Traditionally, maturity period is considered as 100 days after the flower development. Harvesting is done after testing the acid and sugar level of the berries.

Annual life cycle ends in fall after harvesting the fruits, when the plants are in dormant stage. During dormancy, the vine leaves turn yellow and fall. It is necessary to prune properly in this stage, so as to protect the grapevine from extreme frost. Pruning also helps in storing maximum energy for developing leaves and bearing fruits.