Development and validation of a standard area diagram set to evaluate bacterial blight on yellow passion fruit leaves

Rodrigo Martins Monzani,Louise Larissa May De Mio,Henrique Da Silva Silveira Duarte,Forrest Nutter Junior,Grazieli Araldi Da Silva

doi:10.1590/0100-5405/175591

Rodrigo Martins Monzani, Louise Larissa May De Mio + Show 3 more

Open Access

https://doi.org/10.1590/0100-5405/175591

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Abstract

ABSTRACT Bacterial blight is one of the most important diseases of yellow passion fruit. The aim of this study was to develop and validate a set of standard area diagram (SADs) to improve the accuracy and precision of bacterial blight severity assessments on yellow passion fruit leaves. The proposed SADs, composed of illustrations of symptomatic leaves with nine severity levels (1, 2.5, 5, 10, 20, 30, 40, 50 and 62%), were evaluated by 15 raters. Accuracy, precision and reliability of the SADs were validated by quantifying and comparing the assessments performed by 15 raters with and without the use of SADs. The SADs improved accuracy (coefficient of bias, Cb = 0.940 without SADs and 0.967 with SADs), precision (correlation coefficient, r = 0.901 without SADs and 0.949 with SADs) and overall agreement (Lin’s concordance correlation coefficient, ρc = 0.863 without SADs and 0.935 with SADs) of severity estimates. Inter-rater reliability also significantly improved when the SADs were used (coefficient of determination, R2 = 0.717 without and R2 = 0.880 with the SADs; intra-class correlation, ρ = 0.798 without and ρ = 0.926 with the SADs). The developed SADs improved accuracy, precision and reliability of disease severity assessments and are recommended as an aid to assess bacterial blight on yellow passion fruit leaves.

Highlights

0.967 with Standard area diagrams (SADs)), precision and overall agreement (Lin’s concordance correlation coefficient, ρ = 0.863 without SADs and 0.935 with SADs) of severity estimates
All assessments performed with and without the use of SADs resulted in linear relationships between estimated and actual disease severity of bacterial blight
The SADs proposed in this report demonstrated to be an effective tool to estimate disease severity, as they improved accuracy, precision and reliability of the data, reducing the chances of drawing incorrect conclusions, i.e. failing to reject the null hypothesis when the null hypothesis was false [3, 22]

Summary

Introduction

The developed SADs improved accuracy, precision and reliability of disease severity assessments and are recommended as an aid to assess bacterial blight on yellow passion fruit leaves. O objetivo deste estudo foi desenvolver e validar uma escala diagramática para melhorar a acurácia e precisão na avaliação da severidade da mancha-bacteriana em folhas de maracujazeiro-amarelo. A escala diagramática desenvolvida melhorou a acurácia, precisão e reprodutibilidade das avaliações da severidade da doença, sendo recomendada como auxiliar na avaliação da mancha-bacteriana em folhas de maracujazeiro-amarelo. Yellow passion fruit (Passiflora edulis Sims) is the most widely cultivated and consumed passion fruit species produced in Brazil. This country has been the worlds largest producer for more than two decades, accounting for approximately 80% of the global production [18]. The entire leaf is affected, causing wilt with subsequent defoliation, thereby reducing productivity [27]

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