Year: 2020
Type: article
Abstract: Glomerella leaf spot (GLS) is an apple disease difficult to control, even with the use of chemical fungicides.In years of GLS high pressure, protective fungicides in the chemical group of dithiocarbamates, especially mancozeb, have been used frequently, and even so, the control has not been satisfactory.Because of this scenario, growers have been increasing the frequency of application and the dose recommended on the product label, a situation that will become unsustainable over the years, and resistance of some species belonging to Colletotrichum acutatum species complex to mancozeb has already been observed in Brazil.Our objective was to verify the efficiency of several chemicals' fungicides in the control of GLS in field conditions in three consecutive crop seasons.The experiments were conducted at the Experimental Station of Caçador in 2017/2018, 2018/2019 and 2019/2020 crop seasons.The tested fungicides were: mancozeb, mancozeb + trifloxystrobin, mancozeb + trifloxystrobin + tebuconazole, fluxapyroxad + pyraclostrobin, chlorothalonil, dithianon, captan, metiram + pyraclostrobin, thiophanate-methyl + fluazinam, fluazinam, metiram, dodine, folpet, and propineb.We assessed the GLS incidence over time, and with these data, the Area Under the Disease Incidence Progress Curve (AUDIPC) and the control efficiency of each treatment were calculated.The experimental design was in randomized blocks with four replications.The fungicides mancozeb, mancozeb + trifloxystrobin, mancozeb + trifloxystrobin + tebuconazole, chlorothalonil, dithianon, captan, thiophanate-methyl + fluazinam, metiram, fluazinam, folpet and propineb showed an efficient control of GLS.The fungicide metiram + pyraclostrobin showed an intermediate control and the fungicides dodine, and fluxapyroxad + pyraclostrobin were not efficient in GLS control.In general, systemic fungicides were not efficient in GLS control.Protectant fungicides were the most efficient in GSL control, being excellent options to be rotated with the fungicide mancozeb, which is used as a standard in GLS control in Brazil.
Source: Plant Pathology & Quarantine
DOI: 10.5943/ppq/10/1/16
Author: C Ogoshi
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W3119677759