English: tar spot; tar spot of maize; Spanish: mancha de asfalto; mancha negra; mancha negra del maiz; French: tache noire du mais. El “complejo mancha de asfalto” del maíz, su distribución geográfica, requisitos Etiología y manejo de la mancha de asfalto (Phyllachora maydis Maubl.). mancha de asfalto del maiz []. Malaguti, G. Subero, L.J.. Access the full text: NOT AVAILABLE. Lookup the document at: google-logo. mancha de asfalto del.

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Given the increasing importance of the Tar Spot Complex, standardized methods for the quantification of the disease are required, methods that allow the conduction of accurate, precise, and reproducible epidemiological studies; understanding ‘accuracy’ as the proximity that an estimated value has to the real value, ‘precision’ as the variation or repeatability associated with an estimation, and ‘reproducibility’ as the absence of change in the estimations when several evaluators quantify the same characteristics Nascimiento et al.

Infection may also occur at the 8 to 10 leaf stage Hock et al.

In addition, it should be determined how susceptible to either pathogen maize cultivars grown elsewhere in environments favourable for tar spot are. The anamorphic form of Monographella maydis usually grows in the necrotic areas around the ascomata Muller and Samuels, ; Bajet et al. Contribution of Reed Herbarium Reed Herbarium.

Transactions of the Illinois State Academy of Science, Clypeus amphigenous, developing in epidermis, generally circular, 0. Symptoms Top of page Initial symptoms are small, yellow-brown spots on either side of the leaf. Lower leaves should be examined for small, raised, glossy, dark, circular, or oval to irregular, spots, or for brown lesions, often with a dark border, having a dark ascomata at the centres CIMMYT, Tropical Pest Management Design of the diagrammatic logarithmic scale.

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Escala Diagramática de Severidad para el Complejo Mancha de Asfalto del Maíz

According to Sherwood et al. Cryptogamic Botany, 2 ProMED-mail 20 April The accuracy, represented by the degree of proximity of the estimated values to the real values Nutter et al.

Entrez cross-database search engine. This has not been reported, but the natural means of dispersal may not be sufficient to explain asfatlo between environmentally favourable areas of maize cultivation at higher elevations in South America or to islands in the Caribbean.

Most of the spores trapped were in clusters of three or four; the fungus was able to spread up to 75 m from infected plants. The precision and accuracy was determined by a simple linear regression analysis between actual and estimated severity. Studies on the epidemiology of the tar spot disease complex of maize in Mexico. The logarithmic scale was generated through the 2-Log V1. An annotated aefalto of seed-borne diseases.

Rainfall Regime Top of page Bimodal. The overestimation of the severity levels using logarithmic scales has been common in several pathosystem. The higher optimum for the second pathogen may be a factor in its later appearance, following P.

The source of initial inoculum for both fungi is not determined. Given the growing importance, standardized methods are required to quantify disease that allow for reproducible epidemiological methods.

High levels of accuracy were observed; r 2 was comprised between the range of 0.

This has been demonstrated for other pathosystems: The means of persistence and sources of initial inoculum other than maize [ Zea mays ] need to be determined. In regards to this, Michereff et al. Chemical Control Fenpropimorph one or two treatments and mancozeb applied every 10 days were found to be the most effective fungicides in field plot tests in Mexico Bajet et al. Diseases of minor importance or limited occurrence.

The precision levels observed indicate that the first contact with the scale is appropriate for successful implementation in the evaluation of TSC. Initial symptoms are small, yellow-brown spots on either side of the leaf. These scales consist in the representation of a series of plants or parts of plants that show the symptoms of a disease in varying degrees of severity Nascimiento et al.


A guide for field identification. In addition, important questions concerned with whether Monographella maydis or a related species, an endophyte, or epiphyte of maize elsewhere, introduced with P. Under favorable conditions, the foliage of the plant may completely dry out in less than eight days due to the fusion of the lesions of the two pathogenic organisms and due to the possible production of a toxin Hock et al.


Elaboration and validation of diagrammatic key to evaluate white rust severity in Mwiz Summa Phytopathologica, Systematic Mycology and Microbiology Laboratory. In eastern lowland Mexico, the disease is observed on maize throughout the year Bajet et al. Despite the increasing importance of TSC in maize and the resulting need to carry out epidemiological or control studies, there is no standardized quantification method of the disease that provides easily reproducible results among investigators or institutions; therefore, the objective of this investigation was to design and maizz a diagrammatic logarithmic severity scale for the maize – Phyllachora maydis and Monographella maydis – pathosystem that allows the evaluation of the damage caused by the disease in fields, analyzing the accuracy, precision and reproducible values generated with its use.

The value of the b 0 intercept was positive in almost all cases, which indicates that there is a tendency to overestimate the severity of the disease; this tendency was greater for the evaluators without experience.

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