Definition - What does Suckering mean?
Suckering is the removal of all unnecessary shoots which grow on vines as weather warms up. This process can take up to two passes through the vineyards.
The benefits of suckering result in fewer grape clusters and higher concentrations of flavors. It also opens up the canopy for improved air circulation which can prevent mold and mildew.
WineFrog explains Suckering
Suckering is done in the spring and is an important process vital to the production of higher quality of fruit and better use of the vine's energy.
Following bud-break once the weather warms up, there is a rapid acceleration of shoot growth on the vines. They can grow up to an inch per day. By removing these shoots, the vine's energy can be redirected to the growth of fruit, creating higher concentrations of flavonoids (anthocyanins and tannin) in the grapes.