CHEMICAL CONTROL OF FOLIAR DISEASES IN CORN

• Main Author: NICÉSIO FILADELFO JANSSEN DE ALMEIDA PINTO
• Format: Article
• Language: English
• Published: Associação Brasileira de Milho e Sorgo 2004-04-01
• Series: Revista Brasileira de Milho e Sorgo
• Subjects: Zea mays; Exserohilum turcicum; Phaeosphaeria maydis; Puccinaia polysora; fungicides
• Online Access: http://rbms.cnpms.embrapa.br/index.php/ojs/article/view/96/97

This work was carried out to evaluate the efficiency of several fungicides in the control of foliar diseases incited by Phaeosphaeria maydis, Exserohilum turcicum and Puccinia polysora in corn fields. The following fungicides (g a.i. ha-1) were applied in the cultivars BR 3123, BR 3101 and IAEN-I, with a back sprayer, beginning in the pollination stage: tebuconazole (200), mancozeb (2400), tebuconazole + mancozeb (200 + 2400), streptomycin sulphate + oxytetracycline (450 + 45), propiconazole (250), azoxystrobin (150), imibenconazole (150), triforine (285), prochloraz (450), carbendazim (350), chlorothalonil (1125). Plots without fungicide constituted the control. The experimental model used was randomized blocks with 36 treatments in 3 replications, being the fungicidal randomized among the plots and the cultivars inside the plots. Three sprayings were carried out at 10-day intervals. The symptomatological evaluation was accomplished in the pasty grain stage, being given scores from 0 to 5 (0 = absence of lesions or pustules foliate and 5 = lesions in 100% of the leaves, with drought of the plants). It was verified that for the control of the spot of Phaeosphaeria maydis were most efficient the fungicides mancozeb and azoxystrobin; for the control of the blight of Exserohilum turcicum were most efficient the fungicides tebuconazole, imibenconazole, streptomycin sulphate + oxytetracycline, triforine and prochloraz; and for the control of the rust of Puccinia polysora the fungicide azoxystrobin was highly efficient, proceeded by tebuconazole, tebuconazole + mancozeb and imibenconazole.