Fungicidas foliares : resposta sobre incidência fúngica e ardidos em grãos de milho

Abstract

The diseases in corn culture in Brazil have become more effective over time, causing losses in the quality of grains as well as in productivity, mainly due to the occurrence of burned grains. In view of this, this work aims to quantify the incidence of burned grains, as a function of the application of foliar fungicides in the field. A sub-sample of 300 grams was taken from the general sample to quantify the burnt grains, being considered those that presented at least ¼ of their surface with discolorations. For the sanity test, 20 grains per gerbox were placed, totaling 400 grains per treatment, containing autoclaved filter paper soaked in water-agar medium. The Completely Randomized Design (ICD) was used, with 14 treatments and four repetitions, and the data obtained were submitted to variance analysis, and the means were compared by the Scott-Knott test at 5% probability. In the percentages of burned grains, the highest percentages occurred with the treatments Pyrclostrobin+Epoxiconazol+Thiophanate Methyl, Pyrclostrobin+Epoxiconazol, Trifloxystrobin+Proticonazol+Bixafen+Mancozeb and Pyrclostrobin+Epoxiconazol+Carbendazim and the lowest percentages in the treatments Azoxystrobin+Tebuconazole+Carbendazim, Azoxystrobin+Tebuconazole and Azoxystrobin+Tebuconazole+Mancozeb. The incidence of pathogens on the mass of burned grains, indicated Aspergillus spp., Fusarium spp., Penicillium spp., Rhizopus spp.; Nigrospora spp. and Bipolaris spp.