My husband and I recapped what we did this year to try to figure out if there is a more efficient way of doing what seems to be a perpetual shoot positioning, canopy management Sisyphean task.
Well, in the March 2018 issue of Wines & Vines there is an excellent and instructive article on the modified Eichhorn-Lorenz system, Grapevine Phenology Revisited, written by Fritz Westover detailing when the best times are for certain tasks.
Fritz's advice: collecting data about important phenology benchmarks (bud burst, shoots reaching 10 cm, flowering begins, flowering, setting, berries pea size, véraison and harvest) can help make better decisions in the vineyard throughout the growing season.
So, what is the Definition of Phenology:Phenology is the study of natural changes or growth and natural development of an organism and its relation to seasonal changes in climate.1
The article provided a detailed breakdown of the major grape vine phenological events and coupled it with implementation of vineyard-management tasks including canopy management, vineyard nutrient monitoring and pest and disease prevention.1
Phenological Stage | Vineyard Task |
Shoot and Inflorescence Development | •Begin a protective fungicide program when shoots are just 2 inches long •Unwanted “sucker” shoots can easily be removed from trunks and non-count shoots from cordons or fruiting canes |
Flowering | •Sample leaf tissue for nutrient analysis and start to introduce systemic fungicides into their spray programs Greatest window of disease susceptibility is from the period beginning two weeks before bloom and extending four weeks past fruit set •During this time, use the best products and canopy-management practices for preventing fungal diseases on the fruit and the canopy |
Berry Formation | •Greatest window of disease susceptibility is from the period beginning two weeks before bloom and extending four weeks past fruit set •During this time, use the best products and canopy-management practices for preventing fungal diseases on the fruit and the canopy •A fungicide with a long pre-harvest interval (PHI), such as mancozeb (with a PHI of 66 days), must be taken out of a spray program based not on calendar date, but on a phenological indicator |
Berry Ripening | •Second opportunity to sample leaf tissue for nutrient status and can begin to finalize crop estimates for the winery |
Senescence |
References:
1. Fritz Westover, Grapevine Phenology Revisited, Wines & Vines, March 2018.
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