Abstract
The Australian red cedar (Toona ciliata), a forest species native to southwestern Asia, has aroused commercial interest for its high-quality timber. Phyllachora was recently reported in this species in Brazil, but there is a lack of knowledge about its epidemiology and control. Currently, no methodologies exist for quantifying the severity of this disease in cedar trees. In the present study, a diagrammatic scale comprising five levels of disease severity was developed. Validation of the proposed diagrammatic scale was performed by having 13 inexperienced evaluators conduct three assessments, separated by seven-day intervals, of samples with various levels of disease severity. In the first assessment, the evaluators did not use the diagrammatic scale and estimated severity as a percentage. In the second and third assessments, levels were assigned with the aid of the scale proposed in this study. The accuracy and precision of the severity estimates of each evaluator were analyzed by linear regression and Lin’s statistics. The reproducibility of the estimates was evaluated using the coefficient of determination of linear regressions of data from pairs of evaluators. Of 200 leaflets collected to develop the diagrammatic scale, 96% showed severity below 9%, and only 4% showed severity between 9 and 15%. The assessments performed with the scale yielded greater precision, accuracy, reproducibility and reproducibility of estimates than did those performed without the scale. Therefore, it is recommended that the proposed scale be used for the quantification of severity of phyllachora.
Similar content being viewed by others
References
Alvarez-Garcia LA (1940) A Cedar seedling blight in Puerto Rico. Caribb Forester 1(2):1–26
Andrade GCG, Alfenas AC, Mafia RG, Maffia LA, Gonçalves RC (2005) Escala diagramática para avaliação da severidade da mancha foliar do eucalipto causada por Quambalaria eucalypti. Fitopatol Bras 30(5):504–509. https://doi.org/10.1590/S0100-41582005000500007
Bela Vista Florestal (2013) Planting recommendations for Australian cedar: cloned plants version 2.0. http://www.belavistaflorestal.com.br/informativos_e_documentos.php. Accessed 10 Mar 2018
Belan LL, Pozza EA, Freitas ML, de Souza RM, de Jesus Junior WC, Oliveira JM (2014) Diagrammatic scale for assessment of bacterial blight in coffee leaves. J Phytopathol 162(11–12):801–810
Bergamin Filho A, Kimati H, and ed Amorim L (1995) Avaliação de doenças. Manual de fitopatologia: princípios e conceitos. Agronomica Ceres, Sao Paulo, pp 647–671
Bock CH, Poole GH, Parker PE, Gottwald TR (2010) Plant disease severity estimated visually, by digital photography and image analysis, and by hyperspectral imaging. Crit Rev Plant Sci 29(2):59–107. https://doi.org/10.1080/07352681003617285
Campbell CL, Madden LV (1990) Introduction to plant disease epidemiology. New York
Custódio AA, Pozza EA, Guimarães SD, Koshikumo ÉS, Hoyos JM, Souza PE (2011) Comparison and validation of diagrammatic scales for brown eye spots in coffee tree leaves. Ciênc Agrotecnologia 35(6):1067–1076
Damasceno VF, Furtado EL, Ferreira Filho PJ (2014) Comparison of two methods to elaborate and validate a diagrammatic scale for quantifying the severity of Cylindrocladium leaf spot on Eucalyptus. Summa Phytopathol 40(3):248–255
Edmonds JM (1993) The potential value of Toona species (Meliaceae) as multipurpose and plantation trees in Southeast Asia. Commonw For Rev 72:181–186
Forbes GA, Korva JT (1994) The effect of using a Horsfall-Barratt scale on precision and accuracy of visual estimation of potato late blight severity in the field. Plant Pathol 43(4):675–682
Horsfall JC, Barratt RW (1945) An improved grading system for measuring plant diseases. Phytopathology 35:665
Horsfall JG, Cowling EB (1978) Plant diseases An advanced treatise. How plants suffer from disease. vol 3, pp 508
Hua P, Edmonds JM (2008) Toona (Endlicher) M. Roemer, Fam Nat Syn Monogr 1: 131. 1846. Flora of China 11:112–115
Kranz J (1988) Measuring plant disease. In: Kranz J, Rotem J (eds) Experimental techniques in plant disease epidemiology. Springer Verlag, Heidelberg, pp 35–50
Lin L (1989) A concordance correlation coefficient to evaluate reproducibility. Biometrics 45(1):255–268. https://www.jstor.org/stable/2532051
Madden LV, Hughes G, Van den Bosch F (2007) The study of plant disease epidemics. APS Press, St. Paul. https://doi.org/10.1094/9780890545058
Nita M, Ellis MA, Madden LV (2003) Reliability and accuracy of visual estimation of Phomopsis leaf blight of strawberry. Phytopathology 93(8):995–1005
Nuñez AMP, Monteiro FP, Pacheco LP, Rodríguez GAA, Nogueira CCA, Pinto FAMF, Souza JT (2017) Development and validation of a diagrammatic scale to assess the severity of black rot of crucifers in kale. J Phytopathol 165(3):195–203. https://doi.org/10.1111/jph.12550
Nutter Junior FW, Esker PD (2006) The role of psychophysics in phytopathology: The Weber–Fechner law revisited. Eur J Plant Pathol 114(2):199–213. https://doi.org/10.1007/s10658-005-4732-9
Nutter Junior FW, Schultz PM (1995) Improving the accuracy and precision of disease assessments: selection of methods and use of computer-aided training programs. Can J Plant Path 17(2):174–184
Oliveira CA, Pozza EA, Oliveira VB, Santos RC, Chaves ZM (2001) Escala diagramática para avaliação da severidade de cercosporiose em folhas de cafeeiro. In: Simpósio Brasileiro de Pesquisa dos Cafés do Brasil. Anais. Embrapa Café, Brasília, pp 1151–1157
Orwa C, Mutua A, Kindt R, Jamnadass R, Anthony S (2009) Agroforestree database: a tree reference and selection guide version 4.0. ICRAF World Agroforestry. http://www.worldagroforestry.org/sites/treedbs/treedatabases.asp. Accessed 10 Mar 2018
Passador MM, Porcena AS, Masson MV, de Pieri C, Finkenauer E, Furtado EL (2013) Escala diagramática para quantificação da severidade de manchas em folhas de Eucalyptus globulus Labill. causadas por Teratosphaeria nubilosa (Cooke) Crous & U. Braun. Ciênc Florestal 23(2):521–528
Paula PVA, Pozza EA, Santos LA, Chaves E, Maciel MP, Paula JC (2016) Diagrammatic scales for assessing brown eye spot (Cercospora coffeicola) in red and yellow coffee cherries. J Phytopathol 164(10):791–800
R Core Team (2013) R: A language & environment for statistical computing. R Foundation for Statistical Computing, Vienna. Internet Resource: http://www.R-project.org/
Salgado M, Pozza EA, Lima LM, Pereira RT, Pfenning LH (2009) Diagrammatic scale to evaluate severity of phoma leaf blight of coffee trees. Trop Plant Pathol 34(6):422–427
Silva HR, Pozza EA, de Souza PE, Ferreira MA, de Freitas AS, Moreira SI (2018) Cercospora leaf spot in Toona ciliata: Epidemiology and infection process of Cercospora cf. alchemillicola. For Pathol 48(6):e12451
Souza JCAV, Barroso DG, Carneiro JG (2010) Australian cedar (Toona ciliata). Niterói: Rio Rural Program. Technical manual 21:1–12
Stevenson M, Nunes T, Sanchez J, Thornton R, Reiczigel J, Robison-Cox J, Sebastiani P (2012) epiR: An R package for the analysis of epidemiological data. The Comprehensive R Archive Network website. Internet Resource: (verified July 5. 2018)
Zacaroni AB, Sussel AAB, Pozza EA, Mansur TOF (2013) Occurrence of Phyllachora balansae in Toona ciliata in Southern Minas Gerais State, Brazil. Summa Phytopathol 39:219–220
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pereira, R.C.M., de Oliveira, L.M., Tassone, G.A.T. et al. Diagrammatic scale for phyllachora in Australian red cedar. Australasian Plant Pathol. 50, 81–90 (2021). https://doi.org/10.1007/s13313-020-00749-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13313-020-00749-x