Hedging in June

Some of our grape varieties are growing beyond the top catch wire. My husband and I are thinking about hedging or topping our shoots.
What is hedging and what are some of it's ramifications?:¹

• trimming of the vine to produce vertical canopies resembling a hedge
• done at the growing or apical ends of the shoot
• also called tipping or topping
• removes entangling vegetation, facilitating the movement of machinery through the vineyard
• reduces carbohydrate competition between new, expanding leaves and the fruit, but also lowers vine capacity
• increases light and atmospheric exposure of the leaves and fruit
• can stimulate undesirable lateral bud activation
• late hedging (after véraison) seldom activates lateral growth

This brings to question, when should we hedge?²

• light trimming shortly after fruit set leads to improvements in amino acid and ammonia nitrogen levels
• hedge canopies after fruit set if canopy development on normal growth vines is excessive (>20 leaves or nodes per shoot)
• hedging any time before, during, or immediately following bloom will lower yields due to decreased fruit set
• early hedging while soil moisture is abundant will promote lateral shoot growth leading to increased canopy density, increased bunch rot, decreased fruit quality, and possibly, second crop
• severe hedging will delay ripening by reducing leaf area and also exposes unacclimated fruit to direct sunlight, increasing sunburn and berry shrivel
• hedging established vineyards late, light, and in conjunction with regulated deficit irrigation and balanced mineral nutrient management is best

Since we are still in bloom we will wait to hedge until later.
References:
1. Ronald Jackson, Wine Science Third Edition, Elsevier, 2008, pg. 120.
2. Lodi Wine Growers, To Hedge or Not to Hedge?.