The Sap Flow Sensors

transcript

Presentation of a plant based

solution for water management

Description

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?

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 ?

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

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

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

The vine transpiration depends on the climatic demand

Climatic demand

Vine transpirationW

Vine transpiration depends on the amount of water in the soil

High transpirationTr

iratio

No water stress

Moderate transpiration

Moderate Water stress

Transpiration Low

High Water stress

Water Stress is balance between transpiration and climatic demand

High water stress

No water stress

Vine water use (transpiration) reacts to water inputs

Irrigation or rain

Seasonal profile reflects grape varietal effect on water use

Grenache

Take home

Vine Water use (transpiration) depends on:● climatic demand● amount of water available in the soil● plant material (varietal and rootstock)● foliar architecture

WATER SATISFACTION INDEX the ratio between actual

transpiration and maximum transpiration

Pilot irrigation with the Water Satisfaction Index (WSI)

Actual transpiration

Maximum Transpiration

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

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

Budburst

Peak of leaf area

Kcb max

Manage your Water Satisfaction Index to improve your irrigation

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,...)

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

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%.

Typical water management for “a ROSE in Provence, France”

Leaf area Growth

Maximum of Leaf area growthW

Beginning of stomatal regulation

2 shorts periods of high water deficit

Typical water management for “a RED WINE“ in Languedoc, France”

See the Water Status on 360viti

Synchronization and Visualization of the data on 360viti

Watch your data on “360viti” → Link: https://cloud.fruitionsciences.com/login

Visualization of the data on 360viti

Hourly transpirationClimatic Demand

Water Satisfaction Index Daily Transpiration

Contact usfor more information

Ryan Hillryan@fruitionsciences.com

Fruition Sciences • 718 California Blvd, Napa, CAfruitionsciences.com • 360viti.fruitionsciences.com 36

The Sap Flow Sensors

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