Irrigation

Question 1

Past Exam Questions

Answer 1

2017: Water availability is increasingly an issue in some wine producing regions. How can a viticulturist best ensure water sustainably when establishing and managing vineyards in drought-prone regions?
2009: What role does water play in viticulture?
2005: Examine the role of water management during the growing season in the production of quality wine around the world.
2003: Examine the effects of water and heat on vines.
1995: Irrigation is common practice in the New World. Describe the methods used and their effect on the resulting wines. Should Europeans reconsider their historic position?

Question 2

Ways to fight drought

Answer 2

• change rootstocks
• change canopy management
• remove water-based frost protection
• change spacing
• crimping (Hanzell example)
• irrigating at night

Question 3

Examples

Answer 3

SONOMA:
- Hanzell switched to crimping and irrigating at night and dropped irrigation by 75%

SOUTH AFRICA:
- Eben Sadie planting new vineyard using wide spacing and bush vines (in response to crazy drought of 2018)

NAPA:

• Ovid using Fruition Sciences sap flow detection to maximize irrigation efficiency
• Pete Richmond uses TULE (sensor in canopy, shows canopy evaporation)
• At hottest time of year, Pete Richmond did 3x irrigations per week at 1.5/2 gallons of water per vine

GREECE:
- Santorini basket trellising to capture dew

AUSTRALIA:

• 85% of Australian vineyards are irrigated (overhead sprinklers are common, Yalumba switched to drop, saved water by 50%, increased yielids, reduced variability, better quality.)
• Langhorne Creek in South Australia uses flood irrigation

FRANCE:

• As of 2007 it is legal to irrigate in France but controlled - by permit only and exclusively from June 15 - harvest
• In 2003, heat caused the vines to shut down and as a result the ripening was weird

PATAGONIA:
- Chacra only gets 200mm (7-8 inches) of rain a year so flood irrigate 2x per year deep saturation. (labor intense as you must dig ditches)

Question 4

Types of irrigiation

Answer 4

Deficit Irrigation: typically starts after fruit set

PRD: Partial Root Zone Drying – alternates between irrigating one side of a row and then the other
- costly to install as requires 2x irrigation lines

Subsurface irrigation: vines will grow in the lines, dirt clogs pores, no surface evaporation, save 15-20% water, but expensive to install/maintain.

Flood irrigation

note: moisture monitors are good but don’t tell you if the vine is stressed
note: when doing pressure bombs, must test pre-dawn when root tissue is in equilibrium with soil moisture
note: all irrigation systems use electricity and cost money

Question 5

Water and flavor

Answer 5

• many components of wine aromas come via the production of isoprenoid compounds (monoterpenoids), which are produced late in the berry-ripening period in skin or flesh.
• CHANGES IN BERRY SIZE DUE TO IRRIGATION ALTERS THE RATIOS OF THE COMPOUNDS