A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards

Automatic in-field fruit recognition techniques can be used to estimate fruit number, fruit size, fruit skin color, and yield in fruit crops. Fruit color and size represent two of the most important fruit quality parameters in stone fruit (Prunus sp.). This study aimed to evaluate the reliability of...

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Main Authors: Muhammad S. Islam, Alessio Scalisi, Mark Glenn O’Connell, Peter Morton, Steve Scheding, James Underwood, Ian Goodwin
Format: Article
Language:English
Published: American Society for Horticultural Science (ASHS) 2022-10-01
Series:HortTechnology
Subjects:
Online Access:https://journals.ashs.org/horttech/view/journals/horttech/32/6/article-p510.xml
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author Muhammad S. Islam
Alessio Scalisi
Mark Glenn O’Connell
Peter Morton
Steve Scheding
James Underwood
Ian Goodwin
author_facet Muhammad S. Islam
Alessio Scalisi
Mark Glenn O’Connell
Peter Morton
Steve Scheding
James Underwood
Ian Goodwin
author_sort Muhammad S. Islam
collection DOAJ
description Automatic in-field fruit recognition techniques can be used to estimate fruit number, fruit size, fruit skin color, and yield in fruit crops. Fruit color and size represent two of the most important fruit quality parameters in stone fruit (Prunus sp.). This study aimed to evaluate the reliability of a commercial mobile platform, sensors, and artificial intelligence software system for fast estimates of fruit number, fruit size, and fruit skin color in peach (Prunus persica), nectarine (P. persica var. nucipersica), plum (Prunus salicina), and apricot (Prunus armeniaca), and to assess their spatial and temporal variability. An initial calibration was needed to obtain estimates of absolute fruit number per tree and a forecasted yield. However, the technology can also be used to produce fast relative density maps in stone fruit orchards. Fruit number prediction accuracy was ≥90% in all the crops and training systems under study. Overall, predictions of fruit number in two-dimensional training systems were slightly more accurate. Estimates of fruit diameter (FD) and color did not need an initial calibration. The FD predictions had percent standard errors <10% and root mean square error <5 mm under different training systems, row spacing, crops, and fruit position within the canopy. Hue angle, a color attribute previously associated with fruit maturity in peach and nectarine, was the color attribute that was best predicted by the mobile platform. A new color parameter—color development index (CDI), ranging from 0 to 1—was derived from hue angle. The adoption of CDI, which represents the color progression or distance from green, improved the interpretation of color measurements by end-users as opposed to hue angle and generated more robust color estimations in fruit that turn purple when ripe, such as dark plum. Spatial maps of fruit number, FD, and CDI obtained with the mobile platform can be used to inform orchard decisions such as thinning, pruning, spraying, and harvest timing. The importance and application of crop yield and fruit quality real-time assessments and forecasts are discussed.
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spelling doaj.art-a76abca140764a10953cead114ed818c2022-12-22T03:01:39ZengAmerican Society for Horticultural Science (ASHS)HortTechnology1943-77142022-10-01326https://doi.org/10.21273/HORTTECH05098-22A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit OrchardsMuhammad S. IslamAlessio ScalisiMark Glenn O’Connell Peter MortonSteve Scheding James Underwood Ian GoodwinAutomatic in-field fruit recognition techniques can be used to estimate fruit number, fruit size, fruit skin color, and yield in fruit crops. Fruit color and size represent two of the most important fruit quality parameters in stone fruit (Prunus sp.). This study aimed to evaluate the reliability of a commercial mobile platform, sensors, and artificial intelligence software system for fast estimates of fruit number, fruit size, and fruit skin color in peach (Prunus persica), nectarine (P. persica var. nucipersica), plum (Prunus salicina), and apricot (Prunus armeniaca), and to assess their spatial and temporal variability. An initial calibration was needed to obtain estimates of absolute fruit number per tree and a forecasted yield. However, the technology can also be used to produce fast relative density maps in stone fruit orchards. Fruit number prediction accuracy was ≥90% in all the crops and training systems under study. Overall, predictions of fruit number in two-dimensional training systems were slightly more accurate. Estimates of fruit diameter (FD) and color did not need an initial calibration. The FD predictions had percent standard errors <10% and root mean square error <5 mm under different training systems, row spacing, crops, and fruit position within the canopy. Hue angle, a color attribute previously associated with fruit maturity in peach and nectarine, was the color attribute that was best predicted by the mobile platform. A new color parameter—color development index (CDI), ranging from 0 to 1—was derived from hue angle. The adoption of CDI, which represents the color progression or distance from green, improved the interpretation of color measurements by end-users as opposed to hue angle and generated more robust color estimations in fruit that turn purple when ripe, such as dark plum. Spatial maps of fruit number, FD, and CDI obtained with the mobile platform can be used to inform orchard decisions such as thinning, pruning, spraying, and harvest timing. The importance and application of crop yield and fruit quality real-time assessments and forecasts are discussed.https://journals.ashs.org/horttech/view/journals/horttech/32/6/article-p510.xmlartificial intelligencecomputer visioncrop estimationhue anglemachine learningpeachprunus sp.
spellingShingle Muhammad S. Islam
Alessio Scalisi
Mark Glenn O’Connell
Peter Morton
Steve Scheding
James Underwood
Ian Goodwin
A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
HortTechnology
artificial intelligence
computer vision
crop estimation
hue angle
machine learning
peach
prunus sp.
title A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
title_full A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
title_fullStr A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
title_full_unstemmed A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
title_short A Ground-based Platform for Reliable Estimates of Fruit Number, Size, and Color in Stone Fruit Orchards
title_sort ground based platform for reliable estimates of fruit number size and color in stone fruit orchards
topic artificial intelligence
computer vision
crop estimation
hue angle
machine learning
peach
prunus sp.
url https://journals.ashs.org/horttech/view/journals/horttech/32/6/article-p510.xml
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