title: Estimating Leaf Area Index (LAI) in Vineyards Using the PocketLAI Smart-App.
abstract: Estimating leaf area index (LAI) ofVitis viniferausing indirect methods involves some critical issues, related to its discontinuous and non-homogeneous canopy. This study evaluates the smart app PocketLAI and hemispherical photography in vineyards against destructive LAI measurements. Data were collected during six surveys in an experimental site characterized by a high level of heterogeneity among plants, allowing us to explore a wide range of LAI values. During the last survey, the possibility to combine remote sensing data and in-situ PocketLAI estimates (smart scouting) was evaluated. Results showed a good agreement between PocketLAI data and direct measurements, especially for LAI ranging from 0.13 to 1.41 (R² = 0.94, RRMSE = 17.27%), whereas the accuracy decreased when an outlying value (vineyard LAI = 2.84) was included (R² = 0.77, RRMSE = 43.00%), due to the saturation effect in case of very dense canopies arising from lack of green pruning. The hemispherical photography showed very high values ofR², even in presence of the outlying value (R² = 0.94), although it showed a marked and quite constant overestimation error (RRMSE = 99.46%), suggesting the need to introduce a correction factor specific for vineyards. During the smart scouting, PocketLAI showed its reliability to monitor the spatial-temporal variability of vine vigor in cordon-trained systems, and showed a potential for a wide range of applications, also in combination with remote sensing.
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. francesca.orlando@unimi.it.|Cassandra Lab, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. francesca.orlando@unimi.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Orlando
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. ermes.movedi@unimi.it.|Cassandra Lab, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. ermes.movedi@unimi.it.
authors.forename: Ermes
authors.initials: E
authors.lastname: Movedi
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. davide.coduto@studenti.unimi.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Coduto
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. meteoclima@hotmail.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Parisi
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. lucio.brancadoro@unimi.it.
authors.forename: Lucio
authors.initials: L
authors.lastname: Brancadoro
authors.affiliation: Cassandra Lab, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. valentina.pagani@unimi.it.|Department of Economics, Management, and Quantitative Methods, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. valentina.pagani@unimi.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Pagani
authors.affiliation: Department of Agricultural and Environmental Sciences-Production, Land, Agrienergy, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. tommaso.guarneri@unimi.it.|Cassandra Lab, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. tommaso.guarneri@unimi.it.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Guarneri
authors.affiliation: Cassandra Lab, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. roberto.confalonieri@unimi.it.|Department of Economics, Management, and Quantitative Methods, Università degli Studi di Milano, via Celoria 2, I-20133 Milan, Italy. roberto.confalonieri@unimi.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Confalonieri
mesh_terms: D010781:Photography / Q000379:methods*; D018515:Plant Leaves / Q000502:physiology; D058998:Remote Sensing Technology / Q000379:methods*; D027843:Vitis / Q000502:physiology*
keywords: Vitis vinifera; hemispherical photography; leaf area index; plant vigour; smart-app