Dear Pankaj Kumar Mishra

Pls. find the attached files, may help in your research, good luck

https://www.pioneer.com/CMRoot/Pioneer/US/Non_Searchable/agronomy/cropfocus_pdf/charcoal_rot_soy.pdf

https://www.apsnet.org/publications/PlantDisease/BackIssues/Documents/1984Articles/PlantDisease68n12_1086.pdf

http://www.academicjournals.org/journal/AJB/article-full-text-pdf/DA9942036588

Mengistu A, Ray JD, Smith JR, Paris RL (2007). Charcoal rot disease assessment of soybean genotypes using a colony-forming unit index.

Crop Sci., 47: 2453-2461.

https://extension.tennessee.edu/publications/Documents/W345.pdf

http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PDIS.1997.81.4.363

http://extension.agron.iastate.edu/soybean/charcoalrot.html

http://www.acsoja.org.ar/images/cms/contenidos/451_b.pdf

http://www.scielo.br/pdf/sp/v40n2/v40n2a04.pdf

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582003000200002

http://www.sciencedirect.com/science/article/pii/S0944501306000498 https://www.ideals.illinois.edu/bitstream/handle/2142/44241/Jessica_Frohning.pdf?sequence=1

http://www.apsnet.org/publications/plantdisease/backissues/Documents/1984Articles/PlantDisease68n12_1086.pdf

http://www.scielo.br/scielo.php?pid=S0100-41582003000200002&script=sci_arttext

http://apsjournals.apsnet.org/doi/abs/10.1094/PD-89-0526B

http://www.plantmanagementnetwork.org/pub/php/research/2013/soybean/

https://www.plantmanagementnetwork.org/pub/php/research/2008/drought/

Regards

Prof. Houda Kawas

Sir you made a lot of effort but that is not what I want.

I want article on disease severity at the field level through visual observation and symptoms.

Dear Pankaj Kumar Mishra   

 As you mentioned "I want article on disease severity at the field level through visual observation and symptoms". the articles:

https://www.pioneer.com/CMRoot/Pioneer/US/Non_Searchable/agronomy/cropfocus_pdf/charcoal_rot_soy.pdf

mention:  Scores a range from ‘3’ to ‘7’ on Pioneer’s 1 to 9 scale (‘1’ = susceptible, ‘9’ = resistant)

http://www.academicjournals.org/journal/AJB/article-full-text-pdf/DA9942036588

mention:  Disease severity index was determined after 45 days from inoculation with a diseases scale proposed by Mengistu et al.(2007) and diseases severity (%) was calculated using the following

formula:  Disease severity (%) = _(n x v)/5 N X 100

Mengistu A, Ray JD, Smith JR, Paris RL (2007). Charcoal rot disease assessment of soybean genotypes using a colony-forming unit index. Crop Sci., 47: 2453-2461.

https://extension.tennessee.edu/publications/Documents/W345.pdf

mention:  Disease Ratings

http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PDIS.1997.81.4.363

mention: Population density of M. phaseolina Initial soil densities of M. phaseolina microsclerotia and Assessment of host tissue colonization,sampling five plants at growth stage R7, which corresponds to physiological maturity.  Plants were arbitrarily selected from the outer two rows of each plot; two were selected from row 1 and three were selected from row 4. The LSTR of each plant was excised from the cotyledonary node to a maximum of 15 cm down the taproot.

http://extension.agron.iastate.edu/soybean/charcoalrot.html

mention:  about Charcoal rot can be easily misidentified as BSR or SDS

http://www.acsoja.org.ar/images/cms/contenidos/451_b.pdf

mention: five methods of disease assessments were tested using 24 cultivars of MG 3, 4 and 5. The methods were: 1) Root and Stem severity (RSS) based on host tissue colonization; 2) Height of internal stem discoloration measured from the ground level (PSHD); 3) Foliar symptoms taken at the R7 growth stage; 4) Area Under Disease

Progress Curve (AUDPC) using foliar symptoms rated on a weekly basis beginning when the first onset of leaf symptom; and 5) Colony Forming Unit (CFU) measured from the lower stem of each plant by excising from the cotyledonary node to the end of the taproot. Our results indicated that assessment based on stem and root severities was better than disease assessments based on foliar, AUDPC and PSHD in identifying resistance and

predicting colony forming units of M. phaseolina. However, when all disease measurements were combined the regression trend improved significantly. Genotypes that ranked high for resistance as measured by CFU also ranked high using measurements ofRSS, PSHD, foliar symptoms and AUDPC and their combinations

http://www.scielo.br/pdf/sp/v40n2/v40n2a04.pdf and http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582003000200002

mention:  The disease severity in soybean farms at southern Brazil was highest in the 2009/10 growing season. The highest occurrence and severity were found for plants close to the ripening stage, under water stress and high air temperature. Yield losses of up to 50% have been reported in the north of Paraná State, Brazil (9).FERREIRA, L. P.; LEHMAN, P. S.; ALMEIDA, A. M. R. Doencas da soja no Brasil. Londrina: EMBRAPA-CNPSo, 1979. 42p. (EMBRAPA-CNPSo. Circular Tecnica, 1).

https://www.ideals.illinois.edu/bitstream/handle/2142/44241/Jessica_Frohning.pdf?sequence=1

usually: if there are no rate or scale for severity of your disease or its not convincing , you could simulate one, such root fungi to create your own research scale

http://www.apsnet.org/publications/plantdisease/backissues/Documents/1984Articles/PlantDisease68n12_1086.pdf

mention:  field sampling

http://www.scielo.br/scielo.php?pid=S0100-41582003000200002&script=sci_arttext

mention: you may read MATERIAL AND METHODS:  Disease severity in soybean roots of cultivar Embrapa 48 was evaluated by analysis of root fragments during four seasons

http://apsjournals.apsnet.org/doi/abs/10.1094/PD-89-0526B

mention:  The disease was observed in 60% of fields surveyed in northern Iowa (north of latitude 42.5°N), 90% in central Iowa (latitude 41.6 to 42.5°N), and 20% in southern Iowa (south of latitude 41.6°N). Incidence in surveyed fields ranged from 10 to 80%. One 80-ha field in Hampton  had 50% disease incidence. An incidence of 80%, with extensive premature death prior to growth stage R6 (full seed), was observed in a 16-ha field east of Huxley .And the reference:

Paul, MN, 1992; (3) G. S. Smith and T. D. Wyllie. Charcoal rot. Pages 29–31 in: Compendium of Soybean Diseases. 4th ed. G. L. Hartman et al., eds. The American Phytopathological Society, St. Paul, MN, 1999. (4). X. B. Yang et al. Biology and management of soybean charcoal rot. Pages 55–60. in: Proc. 15th Integrated Crop Management Conf. Iowa State University, Ames. 2003.

http://www.plantmanagementnetwork.org/pub/php/research/2013/soybean/

mention:  Disease Ratings for Evaluation of Resistance

Reaction of the 628 accessions to MP was evaluated at the R7 (4) growth stage using the root and stem severity rating (RSS) (8) in 2008 and 2009. Five to ten plants were gently uprooted. Stem and taproots of each plant were split longitudinally (Fig. 1B) and the severity of discoloration was rated on scale of 1 to 5; where 1 = no discoloration and 5 = highly discolored). The scale for RSS was divided into four classifications: resistant (values of 1), moderately resistant (values > 1 and ≤ 2), moderately susceptible (values > 2 and < 3), and susceptible (values 3 to 5), as described by Mengistu et al. (8).

https://www.plantmanagementnetwork.org/pub/php/research/2008/drought/

More article may needed about disease severity

https://research.cip.cgiar.org/confluence/display/GILBWEB/Estimation+of+Disease+Severity++Background

http://bugs.bio.usyd.edu.au/learning/resources/PlantPathology/infection/disease_assess.html

http://www.uvm.edu/~dneher/Publications/Campbell%20Benson%20book%20chapter%201994.pdf

http://www.annualreviews.org/doi/abs/10.1146/annurev.py.22.090184.001025?journalCode=phyto

http://link.springer.com/chapter/10.1007%2F978-3-642-85063-9_5#close

http://www.hillagric.ac.in/edu/coa/ppath/lect/plpath111/Lect.%209.%20Pl%20Path%20111-%20MEASUREMENT%20OF%20DISEASE.pdf

https://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1018297

https://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/463706

Juan P. Puignau. 1992. Producción de soja. OEA Instituto Interamericano de Cooperacion para la Agricultura Dialogo Pp. 259.ISBN 9789290391975

Regards

Prof. Houda KAWAS