Estimating transpiration coefficients of grapevines (Vitisvinifera L.) "Tempranillo" subjected to delayed pruning

Jordi Oliver-Manera1; Omar García-Tejera1; Xavier Vallverdú1; Joan Girona1

1 Institute of Agrifood Research and Technology (IRTA), Efficient Use of Water in Agriculture programme, Lleida, Spain.

Introduction

• Increase in temperatures during ripening period of grapes causes undesirable

properties to wines.

• Crop forcing consist of removing all the leaves and fruits and pruning shoots

to 6-8 buds in spring with the objective of delaying ripening period.;

Materials and Methods

• Plant material: grapevines “Tempranillo” spaced 1,6x2,5 m fully irrigated located in Lleida (41,6oN; 0,52oE).

• Treatments: 4 trees/treatment of Control (no forced), CF-I (forced on 4th of June) and CF-II (forced on 1st of July).

One sap flow probe (CHPM) per tree calibrated using a whole canopy gas exchange chamber.

Objective

• Determine how the crop forcing technique alters transpiration coefficients.;

Results

0

1

2

3

4

5

6

7

8

9

04-25 05-15 06-04 06-24 07-14 08-03 08-23 09-12 10-02

Tran

spir

atio

n(m

m d

ay-1

)

Control

CF-II

CF-I

ETo

0

0.2

0.4

0.6

0.8

1

1.2

1.4

04-25 05-15 06-04 06-24 07-14 08-03 08-23 09-12 10-02

kt(d

ime

nsi

on

less

)

Control

CF-I

CF-II

0

2

4

6

8

10

12

04-05 05-05 06-04 07-04 08-03 09-02 10-02

Leaf

Are

a (m

2)

Control

CF-I

CF-II

Conclusions

• After applying the technique of forcing regrowth, transpiration rate follows the shape of ETo and matches the

pattern of Control treatment in both dates of forcing

• Small differences in kt are attributed to differences in canopy size

𝑘𝑡 = ൗ𝑇𝑟𝑎𝑛𝑠𝑝𝑖𝑟𝑎𝑡𝑖𝑜𝑛 𝑠𝑎𝑝 𝑓𝑙𝑜𝑤𝐸𝑇𝑜

Leaf and shoot removal

AcknowledgmentsThis Project has been funded by the European Union’s Horizon 2020 Research and Innovation Action programme under grant agreement nº 730253 and by the Spannish ministry of Science, Innovation and Universities under grant agreement RTA2015-00089-C02-02.