Resumo

PEREYDA-HERNANDEZ, Juan et al. Etiology and management of tar spot (Phyllachora maydis Maubl.) of maize in Guerrero State, México. Agrociencia [online]. 2009, vol.43, n.5, pp.511-519. ISSN 2521-9766.

Tar Spot complex of maize is important in the tropic of México due to its impact on yield. The causal agents Phyllachora maydis Maubl., Monographella maydis Müller & Samuels and Coniothyrium phyllachorae Maubl. were detected in the Valley of Mochitlán and other municipalities of the state of Guerrero. The disease caused losses of 55.1% of the production. Eighty one hybrids and 25 varieties of free pollination of maize evaluated in this zone against this complex of phytopathogens did not escape the infection; however, the hybrids H-513×CML47, HEIixH-H513 and H-513×CM374 exhibited 7.29, 7.35 and 7.95% severity, and were the most tolerant. H-513 was consistent in its attributes of tolerance, and its progeny represented 77 % of the 22 genotypes most tolerant to the disease. Per yield, RCO38×HEI and H-513×ST-549 were outstanding with 8.2 and 8.1t ha^-1 (19.89 and 13.18 % severity). The varieties evaluated fluctuated from moderately to very susceptible; however, 72 % of these surpassed 4.0 t ha^-1. The utility in the value of grain production was 5.4 times higher with the spraying of Benomyl (0.200 kg ha^-1) than without the spraying of fungicide, while the utility was 2.2 times higher in ear than in grain in the treatment with Benomil, and 12 times higher with spraying of the product than without spraying.

Palavras-chave : Coniothyrium phyllachorae; Monographella maydis; Phyllachora maydis; genetic and chemical control; maize.

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