Palissage Reduces Cluster Zone Lateral Shoots Compared to Hedging

Goals: Hedging grapevines is a common canopy management practice in vineyards in the northeastern United States, however, it is criticized as being a short-term solution to vine vigor because it can stimulate lateral shoot growth, resulting in a repeated cycle of hedging and leaf removal that costs growers time and money. Palissage is an alternative canopy management tool where long shoot tips are tucked down into the canopy (Tuck) or wrapped horizontally along the top of the canopy (Wrap). Anecdotal reports from growers suggested that palissage slowed shoot growth during the growing season earlier and reduced or eliminated the need for leaf removal in the fruiting zone, due to fewer lateral shoots. This work tested the effects of palissage on vegetative and reproductive growth, yield, disease incidence and severity, and juice and wine sensory qualities of Riesling (Vitis vinifera L.) grown in the northeastern United States.

Key Findings:

• Neither palissage treatment affected vine yield in 2015, but Tuck increased yield over that of hedging in 2016.

• Wrap reduced the number of laterals in the fruit zone more than hedging in 2015, but not in 2016.

• Tuck increased rachis length by 1.4 cm over hedging in 2016, but cluster compactness wasn’t reduced by either treatment.

• Tuck and Wrap decreased botrytis incidence slightly in 2016 when compared to hedging.

• A sensory panel found that wines grouped separately by treatment based on aroma.

Impact and Significance: This study demonstrated that palissage, particularly Wrap, was a potentially viable canopy management technique to reduce lateral growth in the fruit zone. Impacts varied by year, but in at least one year, palissage reduced lateral shoot growth in the fruiting zone, increased rachis length, and maintained or increased yield, although fruit in the Tuck treatment was less ripe. The potential long-term impacts of palissage on vine vigor, yield, and fruit quality need to be further explored, but these methods hold promise to break the hedging-leaf removal cycle in vigorous vineyards.