Grapevine Annual Cycle
Growth is slow at first. Leaves and shoots expand and cluster florets develop. As the mean temperature rises, growth and shoot elongation accelerate. After three or four weeks, the period of most rapid growth begins – where shoots can grow an average of 1 inch or more per day. Photosynthesis occurs as soon as there is a green tissue on the shoots, however, due to the high metabolic activity, there is no net production of assimilates until several leaves have fully expanded.