Drought Stress and Young Vines

This past spring, we planted 4200 vines and then were faced with the need to put in our irrigation system, STAT! Between May 30 and July 29, we had approximately 10 weeks of very little or no rain. This period corresponded to the time between flowering and rapid shoot growth. Severe water stress in grape vines can lead to:¹

• Wilting of leaves
• Drooping of tendrils
• Desiccation followed by abscission of shoot tip leaving behind a brown scar at the shoot apex

Fortunately, we were able to get our irrigation system up on running on July 23rd with the help and dedication of our well guy, Tony!
I found some information regarding irrigation and newly planted vines here:
Drought Stress, Vine Performance, and Grape Quality.
For newly planted and young newly bearing vines:

• Irrigate if necessary to avoid severe stress.
• For newly planted vines, drought stress needs to be avoided – irrigation and weed management are necessary – to maintain good establishment.
• Poor winter survival is a much greater risk in newly planted vines that have been exposed to severe drought stress.
• Pay special attention to new “replants” in existing vineyards as these are sometimes forgotten at this point.
• A very conservative approach should be taken with young vines just beginning their bearing cycle (2-5 years old). Crop should be thinned or even dropped completely under severe drought conditions as it may affect the winter sensitivity (cold damage) and long term survivability of the vines.

References:
1. Bhaskar Bondada, Janani Shutthanandan, "Understanding Differential Responses of Grapevine (Vitis vinifera L.) Leaf and Fruit to Water Stress and Recovery Following Re-Watering", American Journal of Plant Sciences, 2012, 3, 1232-1240.