CANOPY MANAGEMENT AND VINE BALANCE

Transcription

1 World Class. Face to Face. BCWGC Annual Meeting Penticton, BC 20 July 2015 CANOPY MANAGEMENT AND VINE BALANCE Michelle M. Moyer, Ph.D. Assistant Professor Statewide Viticulture Extension Specialist WSU-IAREC Prosser, WA wine.wsu.edu

2 GLOBALIZATION OF CANOPY MANAGEMENT Canopy management techniques are taught / transferred globally Some techniques are adopted without background Some techniques are discarded without due course Some techniques are abused They are used for the wrong reasons They are overused due to a lack of (fill in the blank).

3 Jackson and Lombard Am. J. Enol. Vitic. 44: CANOPY MANAGEMENT FRUIT QUALITY A quick edit to a classic concept

4 January February March April May June July August September October November December January February March April May June July August September October November December Temperature (*C) Precipitation (mm) Temperature (*C) Precipitation (mm) CLIMATE DICTATES MANAGEMENT Penticton Saanich Precip High T Low T Precip High T Low T

5 CLIMATE DICTATES MANAGEMENT Penticton Irrigated production allows the grower to dictate the environment to the plant Cold winters can limit tool sets used in dormant pruning Saanich Rain fed production allows the grower to adjust plant development in response to the environment Cool / cloudy growing season requires larger canopy

6 CANOPY MANAGEMENT Trellising, Training, Manipulation

7 TRELLISING VINE SPACING Low Vigor Sites Narrow planting increases vines per acre and potential yield per acre Wide spacing may result in canopy gaps (inefficient use of trellis for light capture) High Vigor Sites Wider spacing allows each vine to optimize area for sunlight capture Narrow density results in excess crowding and competition for light

8 TRELLISING ROW SPACING

9 TRAINING: VERTICAL SHOOT POSITIONING The Practice: Designed to keep shoots off the ground Easy to spray, train vines

10 Adapted from Smart & Robinson Sunlight into Wine. Winetitles. TRAINING: VERTICAL SHOOT POSITIONING The Practice: Designed to keep shoots off the ground Easy to spray and hedge vines The Benefits: Aids in disease management if fruit zone is exposed Easy adoption of mechanization

11 Photo by Dr. Patty Skinkis, Oregon State University VSP THE BENEFITS Fruit confined to a more limited space Shoot tips confined to a more limited space Uniformity allows for improved efficiency in some practices

12 Adapted from Smart & Robinson Sunlight into Wine. Winetitles. VERTICAL SHOOT POSITIONING The Practice: Designed to keep shoots off the ground Easy to spray and hedge vines The Benefits: Aids in disease management if fruit zone is exposed Easy for mechanization The Drawbacks: NOT APPROPRIATE FOR HIGH VIGOR SITES Reduces overall exposed canopy surface area

13 VSP THE DRAWBACKS High Vigor Low Vigor

14 VSP THE DRAWBACKS Laborious In high-vigor sites: Can result in densely-packed shoots which cause shading of interior leaves In sunny climates can result in over-exposure of fruit Dense canopies can prevent airflow through vineyard Additional passes needed for shoot thinning and hedging

15 TRAINING MODIFIED VSP Advantages More open canopy for sunlight capture Dappled shade on fruit Less laborious Disadvantages Difficult to maneuver down roads Not as visually appealing Can block fruit zone for laterseason sprays

16 Image from: TRAINING SCOTT HENRY Advantages Adopted to existing VSP trellis (lower canopy height!) Increases shoots / meter without added density Disadvantages Not good for mechanization Yield and ripening differences between zones

17 MANIPULATION HEDGING Removing actively growing shoot tips can stimulates lateral shoots INCREASED canopy density in some instances Breaking of apical dominance Creates a new crop of young tissue during a high pressure time for powdery mildew infection

18 MANIPULATION HEDGING Removing actively growing shoot tips can stimulates lateral shoots INCREASED canopy density Will likely then have to go through and remove laterals Creates a new crop of young tissue during a high pressure time for powdery mildew infection Common mistakes with hedging: Inappropriate timing Done too severely Done as the only means of canopy control

19 Vasconcelos and Castagnoli Am. J. Enol. Vitic. 51: BENEFITS TO HEDGING / TIPPING If done appropriately, there are benefits to hedging, outside of canopy control Tipping at bloom in Oregon Pinot noir : improved set, smaller berries Light tipping, done around bloom, removes the shoot sink (temporarily)

20 MANIPULATION FRUIT-ZONE LEAF REMOVAL Prebloom Bloom Prebloom fruit-zone leaf removal BEFORE Prebloom fruit-zone leaf removal AFTER

21 Slide Courtesy Dr. Patty Skinkis (OSU). Data from: Feng et al Food Chem. p LEAF REMOVAL FRUIT COMP. COOL CLIMATE Main results: No differences in basic ripening (TSS, ph or TA) Increased certain anthocyanins with leaf removal Increased β-damascenone with 100% leaf removal Greatest increases in 2010 high canopy density and planting density vineyard

22 Komm and Moyer AJEV. In review. LEAF REMOVAL FRUIT COMP. WARM CLIMATES Riesling Sauvignon blanc Free ammonia WA grapes notoriously low in YAN Timing of leaf removal can influence YAN numbers Practically YAN additions would still be required Terpenes In Riesling in 2013, pre-bloom leaf removal resulted in higher levels of terpenes (1.0 µg/ml) relative to the control (0.52 µg/ml)

23 WHAT ABOUT VINE BALANCE? Pruning to Optimize Productivity and Quality

24 WHAT IS VINE BALANCE Vine Balance is: Matching vegetative growth to reproductive growth Sustainability in maintaining quality and quantity of fruit while maintaining overall vine heal Vine Balance is not: A pre-determined yield per acre without consideration of the site High-yields at a cost to vine health Low-yields at a cost (excess labor inputs)

25 VINES WILL RESPOND TO WHAT IS GIVEN TO THEM Capacity: Productivity of the whole vine Vigor: Growth rate of vine shoots

26 CANOPY MANAGEMENT AND VINE BALANCE

27 Dry, P.R., P.G. Iland, and R. Ristic What is vine balance? Proc. AUS Wine Ind. Tech Conf. p YIELD TO PRUNING WEIGHT Yield : Pruning Weight > 10 Interpretation* Cool Climates: May be appropriate if climate is cool; however, ratio should not go below 2. Moderate Climates & Hot Climates: High vigor, low fruitfulness, dense canopy. Indicates under-cropping. Cool Climates: Optimal when on the low end; ratios above 5-6 may indicate over-cropping. Moderate Climates: Optimal Hot Climates: Optimal when on the high end. Ratios below 5 may indicate under-cropping. Cool Climates & Moderate Climates: May indicate over-cropping. Hot Climates: May be appropriate as long as the vine can adequately ripen the crop. *Climate, in this scenario, refers to the temperatures during the growing season. I suggests the following definitions for climate classifications (for example purposes only): Cool Climates are <1175 GDD (10ºC), Moderate Climates are GDD (10ºC) and Hot Climates are >1675 GDD (10ºC).

28 Y:P CAUTION Canopy management techniques change pruning weights Hedging Shoot thinning Removes vegetative tissue Many canopy management techniques result in a higher-than-expected Y:P Indicating balance when you might be undercropping

29 STRATEGIES FOR MEASURING / TRACKING BALANCE Are you meeting harvest requirements? These exclude extreme environmental factors (i.e., inappropriate site selection for the variety) If not, then: Try a crop load trial where yields are adjusted; If close, then: Select sentinel vines for tracking (cluster, berry, pruning weights) Record for at least 2 vintages, and calculate a site:variety-specific ratio for your goals; then.

30 ADJUSTING IN-SEASON YIELDS... Adjust yields the following season if needed, based on historical vegetative growth Does your estimated yield match what your typical yields should be?

31 BALANCE TAKES TIME / TRAINING Image from:

32 QUESTIONS? VITICULTURE EXTENSION WASHINGTON STATE UNIVERSITY World Class. Face to Face. Office: