The Crush.February2021 - 1

theCrush
Volume 48 Issue 2 February 2021

FEATURE STORY

Precision Vineyard Management

MEASURE, MODEL AND MANAGE FOR VARIABLE RATE INPUTS
By Ted Rieger
Grape growers are increasingly implementing precision
viticulture to address labor availability and management and
input costs while also improving efficiency, grape yields and
fruit quality. During the 2021 Unified Wine & Grape Symposium
session titled " Precision Management in Vineyards, " a panel
of vineyard managers and researchers discussed current and
developing tools and technologies to enable variable rate inputs.
Nick Dokoozlian, E. & J. Gallo Winery vice president of
winegrowing research, outlined the basic steps to create a
precision management program:
*	 Measure key plant performance metrics. Collect integrated,
geospatial measures for real-time monitoring of plant growth
and canopy health, plant and soil water and nutrient status,
and pests and diseases.
*	 Model plant response to key parameters. Determine geospatial
relationships among key plant performance metrics and
impactful environmental and physiological parameters.
*	 Manage variable rate applications for optimization. Develop
and deploy variable rate management systems to optimize
productivity and quality within each production block.
Dokoozlian said early tools available to measure plant
performance were yield monitors on mechanical harvesters, used
to create vineyard yield maps and show production variability,
and remote sensing with aerial imagery, available from NASA's
Landsat satellite program or from commercial imagery providers.
Newer tools and technologies are available for precision
viticulture and additional research and development is
ongoing. The Efficient Vineyard Project, supported by
the National Grape Research Alliance,
evaluated many precision viticulture
technologies and more information can be
found on its website.

Variable rate shoot thinning tool in operation on a VMech 2220 tool trailer.
Photo: Ted Rieger

VARIABLE RATE IRRIGATION
Dokoozlian said key measurable factors driving vineyard yield
and quality variability are soil anion content, soil compaction,
soil textural class and pH; however, water holding capacity can
account for nearly 50%. " The amount of water available to a plant
is the main factor that drives yield variability, " he said. " Precision
irrigation practices are our biggest means to address yield and
fruit quality variability. "
A cabernet sauvignon vineyard where Gallo performed variable
rate irrigation studies had an average yield of 9.2 tons per acre
(TPA), but blocks within the vineyard varied from 2-3 TPA to
16-17 TPA. In addition, measured vine water use varied from
28 gallons per week to 17 gallons per week. " When we flip the
switch on a standard irrigation system that is giving out the same
amount over the entire block it results in overwatering some
vines and underwatering some vines, " Dokoozlian said. Gallo
worked with irrigation suppliers to install a variable rate drip
irrigation (VRDI) system. Individual irrigation blocks were set up
https://www.efficientvineyard.com/ https://www.graperesearch.org/research/current-research/ https://www.efficientvineyard.com/
The Crush.February2021

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