Estimate of soybean defoliation via digital image processing in software

Roger Nabeyama Michels, Marcelo Giovanetti Canteri, Marcelo Augusto de Aguiar e Silva, Carlos Alberto Paulinetti da Câmara, Janksyn Bertozzi, Tatiane Cristina Dal Bosco


This study aimed to develop and validate the digital image processing software to quantify leaf coverage, employing the correlation of defoliation values and NDVI with various gradients of defoliation severity of the Asian soybean rust pathosystem. The digital images were obtained from the experiment conducted in 2013/2014. To conduct the experiment, 4 treatments (3 replicates) were adopted, considering the useful floor area of each plot (4 linear meters, 3 lines spaced at 0.45 m). The gradients of defoliation were obtained by treatment with fungicide to control Asian soybean rust. The quantification of the disease severity was performed through diagrammatic scale. The NDVI values were obtained using the GreenSeeker®, conducting the equipment above the plants. The digital photos were obtained in three heights and subsequently processed in software. Then the defoliation sampling was held in 10 plants through treatment. The image processing data correlated with defoliation (94.22%) and with NDVI (89.27%), and we also observed the correlation of defoliation with NDVI (96.12%). These data suggests the use of digital images as an alternative to quantify the vegetation cover, with the advantage of being a dynamic and fast method that does not require experience from the assessor to quantify soybean defoliation.


Phakopsora pachyrhizi. NDVI. Reflectance. Leaf coverage. RGB.

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ALI, A. M., IBRAHIN, A., MAHMOUD, I. S. Using Greenseeker active optical sensor for optimizing maize nitrogen fertilization in calcareous soils of Egypt. Archives of Agronomy and Soil Sciense, v. 64, n. 8, p. 1083-1093, 2018. Doi:

AMADO, T. J. C., VILLALBA, E. O. H., BORTOLOTTO, R. P., DALLA NORA, D., BRAGAGNOLO, J., LEÓN, E. A. B. Yield and nutritional efficiency of corn in response to rates and splits of nitrogen fertilization. Revista Ceres, v. 64, n. 4, p. 351-359, 2017. Doi:

BEYER, S. F., BEESLEY, A., ROHMANN, P. F. W., SCHULTHEISS, H., CONRATH, U., LANGENBACH, C. J G. The Arabidopsis non-host defence-associated coumarin scopoletin protects soybean from Asian soybean rust. The Plant Journal, v. 99, p. 397-413, 2019. Doi:

CAO, Q., MIAO, Y., FENG, G., GAO, X., LI, F., LIU, B., Y, S., CHENG, S., USTIN, S. L. KHOSLA, R. Active canopy sensing of winter wheat nitrogen status: An evaluation of two sensor systems. Computers and Electronics in Agriculture, v. 112, p. 54-67, 2015. DOI:

CRUSIOL, L. G. T., CARVALHO, J. DE F. C., SIBALDELLI, R. N. R., NEIVERTH, W., RIO, A. DO, FERREIRA, L. C., PROCÓPIO, S. DE O., MERTZ-HENNING, L. M. NDVI variation according to the time of measurement, sampling size, positioning of sensor and water regime in different soybean cultivars. Precision Agriculture, v. 18, n., 4, p. 470-490, 2017. Doi:

CRUZ, M. F. A., RODRIGUES, F. Á., DINIZ, A. P. C., MOREIRA, M. A., BARROS, E. G. Soybean resistance to Phakopsora pachyrhizi as affected by Acibenzolar-S-Methyl, jasmonic acid and silicon. Journal of Phytopathology, v. 162, n. 2, p. 133-136, 2014. DOI:

DE LA CASA, A., OVANDO, G., BRESSANINI, L., MARTINEZ, L., DIAZ, G., MIRANDA, C. Soybean crop coverage estimation from NDVI images with different spatial resolution to evaluate yield variability in a plot. Journal of Photogrammetry and Remote Sensing, v. 146, p. 531-547, 2018. Doi:

GARCÉS-FIALLO, F. R., DANELLI, A. L. D., TONIN, R. B., BOLLER, W. Droplet spectrum and fungicide efficiency in the control of Asian soybean rust (Phakopsora pachyrhizi Syd. & P. Syd). Acta Agronómica, v. 67, n. 2, p. 362-367, 2018. Doi: https://doi.org10.15446/acag.v67n2.62865.

GLIER, C. A. DA S., DUARTE JUNIOR, J. B., FACHIN, G. M., COSTA, A. C. T. DA, GUIMARÃES, F. V., MROZINSKI, C. R. Defoliation percentage in two soybean cultivars at different growth stages. Revista Brasileira de Engenharia Agrícola e Ambiental, v. 19, n. 6, p. 567-573, 2015. DOI:

GOELLNER, K., LOEHRER, M., LANGENBACH, C., CONRATH, U., KOCH, E., SCHAFFRATH, U. Phakopsora pachyrhizi, the causal agente of Asian soybean rust. Molecular Plant Pathology, v. 11, n. 2, p. 169-177, 2010. DOI:

GODOY, C. V., KOGA, L. J., CANTERI, M. G. Diagrammatic scale for assessment of soybean rust severity. Fitopatologia Brasileira, v. 31, n. 1, p. 63-68, 2006. DOI:

GUAN, J., NUTTER JR., F. W. Relationships between defoliation, dry weight, percentage reflectance, leaf-to-stem ratio, and green leaf area index in the alfalfa leaf spot pathosystem. Crop Science, v. 42, p. 1264-1273, 2002. Doi:

HIKISHIMA, M., CANTERI, M. G., GODOY, C. V., KOGA, L. J., SILVA, A. J. Quantificação de danos e relações entre severidade, medidas de refletância e produtividade no patossistema ferrugem asiática da soja. Tropical Plant Pathology, v. 35, n. 2, p. 96-103, 2010. DOI:

HIRANO, M., HIKISHIMA, M., SILVA, A. J. DA, XAVIER, S. A., CANTERI, M. G. Validação de escala diagramática para estimativa de desfolha provocada pela ferrugem asiática em soja. Summa Phytopathologica, v. 36, n. 3, p. 248-250, 2010. DOI:

HOSSAIN, M., YAMANAKA, N. Pathogenic variation of Asian soybean rust pathogen in Bangladesh. Journal of General Plant Pathology, v. 85, n. 2, p. 90-100, 2019. Doi:

JUNGES, A. H., FONTANA, D. C., LAMPUGNANI, C. S. Relationship between the normalized difference vegetation index and leaf area in vineyards. Bragantia, v. 78, n. 2, p. 297-305, 2019. Doi:

LIANG, W., KIRK, K. R., GREENE, J. K. Estimation of soybean leaf area, edge, and desfoliation using color image analysis. Computers and Electronics in Agriculture, v. 150, p. 41-51, 2018. Doi:

MARQUES, V. DA C., SILVA, J. DOS S., PRESUMIDO, P. H., DAL BOSCO, T. C., MICHELS, R. N., BERTOZZI, J. Validation of leaf cover analysis software (LCAS) to monitor lettuce cultivated with organic fertilizer. Acta Iguazu, v. 7, n. 5, p. 82-91, 2018.

MARTIN, T. N., MARCHESE, J. A., SOUSA, A. K. F. DE, CURTI, G. L., FOGOLARI, H., CUNHA, V. DOS S. Uso do Software ImageJ na estimativa de área folia para a cultura do feijão. Interciencia, v. 38, p. 843-848, 2013.

MARTINELLI, F. SCALENGHE, R., DAVINO, S., PANNO, S., SCUDERI, G., RUISI, P., VILLA, P., STROPPIANA, D., BOSCHETTI, M., GOULART, L. R., DAVIS, C. E., DANDEKAR, A. M. Advanced methods of plant disease detection. A review. Agronomy for Sustainable Development, v. 35, p. 1-25, 2015. Doi:

MICHELS, R. N., BERTOZZI, J., DAL BOSCO, T. C., AGUIAR E SILVA, M. A., GNOATTO, E., SOARES, C. H. E. Use of drone with digital photographic machine embedded for determination of leaf cover. Revista Agrogeoambiental, v. 11, n. 1, p. 17-25, 2019. Doi:

MICHELS, R. N., BONAFE, E. G., FIGUEIREDO, L. C., SUZUKI, R. M., TONIN, L. D., MONTANHER, P. F., MARTINS, A. F., VISENTAINER, J. V., CANTERI, M. G., AGUIAR E SILVA, M. A. Effects of different numbers of fungicide application on the proximate composition of soybean. Journal of the Brazilian Chemical Society, v. 37, n. 20, p. 1727-1735, 2016. Doi:

ORIMOLOYE, I. R., OLOLADE, O. O., MAZINYO, S. P., KALUMBA, A. M., EKUNDAYO, O. Y., BUSAYO, E. T., AKINSANOLA, A. A., NEL, W. Spatial assessment of drought severity in Cape Town área, South Africa. Heliyon – Natural Hazards, Ecology, Environmental Science, v. 5, n. 7, 2019. Doi:

PREY, L., VON BLOH, M., SCHMIDHALTER, U. Evaluating RGB imaging and multispectral active and hyperspectral passive sensing for assessing early plant vigor in winter wheat. Sensors, v. 19, n. 9, p. 2931, 2018. Doi:

RITCHIE, G. L.; BEDNARZ, C. W. Estimating desfoliation of two distinct cotton types using reflectance data. The Journal of Cotton Science, v. 9, p. 182-188, 2005.

RONGTING, J., MIN, J., YUAN, W., CHENG, H., HAILIN, Z., WEIMING, S., In-season yield prediction of cabbage with a hand-held active canopy sensor. Sensors, v. 17, n. 10, p. 2287, 2017. Doi:

VIAN, A. L., BREDEMEIER, C., TURRA, M. A., GIORDANO, C. P DA S., FOCHESATTO, E., SILVA, J. A. DA, DRUM, M. A. Nitrogen management in wheat based on the normalized difference vegetation index (NDVI). Ciência Rural, v. 48, n. 9, p. 8-24, 2018. Doi:

YAMANAKA, N., MORISHITA, M. MORI, T., MURAKI, Y., HASEGAWA, M. HOSSAIN, M. M., YAMAOKA, Y., KATO, M. The locus for resistance to Asian soybean rust in PI 587855. Plant Breeding, v. 135, p. 621-626, 2016. Doi:

ZARATE-VALDEZ, J., WHITING, M. L., LAMPINEN, B. D., METCALF, S., USTIN, S. L., BROWN, P. H. Prediction of leaf area index in almonds by vegetation indexes. Computers and Electronics in Agriculture, v. 85, p. 24-32, 2012. DOI:

ZHANG, G., XU, T., ZE, Z., YINXI, D.; XIN, L. Monitoring of Aphis gossypii using Greenseeker and SPAD meter. Journal of the Indian Society of Remote Sensing, v. 45, n. 2, p. 361-367, 2017. Doi:

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