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The Sap Flow Sensors 1
The Sap Flow Sensors
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Presentation of a plant based
solution for water management
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Description
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With the sap flow sensors, you can “listen” to your vines in real time, continuously throughout the season.
The sap flow sensors are set up directly on the vine. They measure the transpiration of the vine, so we can monitor vineyard water use, and pilot irrigation if needed, thanks to the calculation of the Water Satisfaction Index.
What are the benefits for my vineyard?
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Apply an amount of water adapted to the terroir and production objectives
Define the best timing for irrigation thanks to the Water Satisfaction Index
Save water!
Adjust practices to better match vineyard needs
(ie. canopy reduction to reduce vine water use, cover crop reduction to increase vine water use,..)
Improve wine and vineyard fruit quality
Help to better understand vine response to terroir (climatic demand, varietal, rootstock, site properties, practices, etc..)
How does it work ?
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4 steps :
1 2 3 4
Transpiration is measured every 15 minutes
The data is stored and sent automatically to our servers every 2 hours
The data is analyzed in real time and the Water Satisfaction Index is calculated
You can see the results and follow your vine water status on our platform : 360viti
Organization of one site of sap flow sensors
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1 site of sap flow is composed of:- 2 sensors on 2 different vines in the
same row - 1 system of data-logger to store
the data (SAPIP)- 1 Arduino to send the data in real
time - 1 power pack : 1 battery, 1
regulator, 1 solar panel and its pillar
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1
2
3
4
Heater provides a continuous heat of the sap
Thermocouples measure the temperature of the sap before and after the heat
The sensors are connected to a battery and a data logger, to store the data and to have the power to heat the sap
The sensor (length: from 5 to 10 cm) is set on last year shoot (guyot) or on the cordon. Measurements of temperature are used to calculate the flow rate of the sap.
Velcro to tighten the sensor around the shoot
Zoom on the sensor
The Water Satisfaction Index
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The vine transpiration depends on the climatic demand
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Climatic demand
Vine transpirationW
ater
use
(mm
/hr)
Vine transpiration depends on the amount of water in the soil
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High transpirationTr
ansp
iratio
n (m
m/h
r)
No water stress
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Moderate transpiration
Tran
spira
tion
(mm
/hr)
Moderate Water stress
Vine transpiration depends on the amount of water in the soil
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Transpiration Low
Tran
spira
tion
(mm
/hr)
High Water stress
Vine transpiration depends on the amount of water in the soil
Water Stress is balance between transpiration and climatic demand
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High water stress
Tran
spira
tion
(mm
/hr)
No water stress
Vine water use (transpiration) reacts to water inputs
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Irrigation or rain
Irrigation or rain
Tran
spira
tion
(mm
/day
)
Irrigation or rain
Seasonal profile reflects grape varietal effect on water use
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Syrah
Grenache
Tran
spira
tion
(mm
/day
)
Take home
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Vine Water use (transpiration) depends on:● climatic demand● amount of water available in the soil● plant material (varietal and rootstock)● foliar architecture
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WATER SATISFACTION INDEX the ratio between actual
transpiration and maximum transpiration
Pilot irrigation with the Water Satisfaction Index (WSI)
Actual transpiration
Maximum Transpiration
=
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Applications
A : Root water supply is non limiting
⇒ vine transpires all the water it needs to match climatic demand ⇒ Actual transpiration = Maximum transpiration ⇒ WSI = 100%
B : Root water supply is limited
⇒ vine transpires less water than it would if water supply were non limited.⇒ vine water use is less than climatic demand⇒ Actual transpiration < Maximum transpiration ⇒ WSI < 100%
The calculation of basal crop coefficient from Maximum transpiration
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Definition
Maximum transpiration Kcb max / ETref
measured from weather station.depends on global radiations, VPD and wind.
Reference Evapotranspiration (FAO method - Allen et al, 1998)
Basal Crop coefficient
=
measured from sap flow
The basal crop coefficient : Kcb
Kcb
0
0.6
GDD
Budburst
Peak of leaf area
Kcb max
Manage your Water Satisfaction Index to improve your irrigation
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WSI > 60 %→ No water stress
40 % < WSI < 60 %→ Moderate water stress
WSI < 40 %→ High water stress
Thresholds vary according to production objectives: yield and quality.
The Water Satisfaction thresholds :
These thresholds must be adapted to regions and production objectives
==> A severe level of water deficit is considered to be under:● 40% in arid areas (premium reds in Napa, California), or ● 60% in other context (Rose, Cognac,...)
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How to modulate irrigation according to vine seasonal stage ?
Period 2
Budbreak BLOOM SET Peak N leaf Kcb max
Kcb max Veraison
Period 3
Change in Sugar accumulation rate
Veraison
Period 4
Change in Sugar accumulation rate
Period 5
Peak color
Harvest
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Examples of WSI water management
Red wines :
Period 2 : actual transpiration is maximum transpiration and increases every day. WSI is computed after vine stops growing. Make sure growth does not stop too late (risk of vegetative notes in final wine)
Period 3 : WSI can go down to 50% for gain a) in fruit phenolics ; b) in vine resistance to drought
Periods 4 and 5 : no expected benefits to imposing water stress. It is advisable to stay above 60%.
White wines and rosés :
Period 2 : actual transpiration is maximum transpiration and increases every day. WSI is computed only after vine stops growing. Make sure growth does not stop too early (ie.risk of too small leaf area to ripen fruit).
Period 3 : WSI maintained above 60% to increase berry size and boost flavor precursors
Periods 4 and 5 : no expected benefits to imposing water stress. It is advisable to stay above 70%.
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Typical water management for “a ROSE in Provence, France”
X
Leaf area Growth
Wat
er S
atis
fact
ion
inde
x (%
)
X
Maximum of Leaf area growthW
ater
Sat
isfa
ctio
n in
dex
(%)
Typical water management for “a ROSE in Provence, France”
X
Beginning of stomatal regulation
Typical water management for “a ROSE in Provence, France”
Wat
er S
atis
fact
ion
inde
x (%
)
Typical water management for “a ROSE in Provence, France”
Wat
er S
atis
fact
ion
inde
x (%
)
Wat
er S
atis
fact
ion
inde
x (%
)
Typical water management for “a ROSE in Provence, France”
2 shorts periods of high water deficit
Typical water management for “a RED WINE“ in Languedoc, France”
See the Water Status on 360viti
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Synchronization and Visualization of the data on 360viti
Watch your data on “360viti” → Link: https://cloud.fruitionsciences.com/login
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Visualization of the data on 360viti
Hourly transpirationClimatic Demand
Water Satisfaction Index Daily Transpiration
Contact usfor more information
Ryan [email protected]
Fruition Sciences • 718 California Blvd, Napa, CAfruitionsciences.com • 360viti.fruitionsciences.com 36
