Chapter 1

Annual Growth Cycle of the Grapevine

Berry Growth

Stages of Berry Growth

Berry growth occurs in three general stages: (1) rapid initial growth; (2) followed by a shorter period of slow growth; and (3) finishing with another period of rapid growth.

Stage 1 - Rapid Growth Phase

The first stage of berry development starts soon after fertilization of the flower and is characterized by strong growth of the seed and berry. During this stage, the berries are firm, dark green in color, and rapidly accumulate acid. In this period, the diameter of the grape berry may double in size.

Stage 2 - Lag Phase

The next stage, called the lag phase, is a time of slow growth. Berries remain firm, but begin to lose chlorophyll (See Figure 1.6). Berries reach their highest level of acid content and begin to accumulate sugar slowly. Toward the end of this stage as véraison (stage 3) approaches, color changes occur in the berry.

Stage 3 - Veraison Phase

The final stage of berry growth coincides with the beginning of fruit maturation (ripening). At this stage growth accelerates again; berries begin to soften, titratable acidity (TA) decreases and pH and soluble solids (°Brix) increases. Berries ripen unevenly among and within clusters (See Figure 1.7).

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