How well a vineyard is trellised will have a big impact how much good fruit the winemakers will receive this year with current rains in Northern California.
Until the 60's the best practice for trellising vines was the head-trained. However this method also proved a loss of fruit to sunburn and excessive growth which would strain the fruit.
In the 70's T-trellising became the best practice. Growers were able to control the air movement and sunburn with vines draped over wires.
In the 90's a new practice of Vertical Shoot Positioning (VSP) became the standard practice in California. This method controls growth, the amount of sun and air flow.
Open-U, or Lyre are also common place vineyard trellising. It spreads the grapes in to vertical curtains. This protects against vigorous rootstock and aggressive soils.