Detection of fungal problems in çukurova onion cultivation ( Allium cepa L. ) and determination of susceptibility of common species to some fungicides

In this study, which was carried out in the Adana in 2019-2020, a survey was conducted for fungal pathogens that are a problem in seedling, head tying and onion fields close to harvest. In vitro susceptibility of six fungi (Stemphylium globuliferum, Stempyhlium vesicarium, Botrytis cinerea, Fusarium equiseti, Alternaria infectoria, Penicillium glabrum) obtained from infected plants brought to the laboratory from the survey areas to some fungicides was tried to be determined. As a result of the surveys, factors related to Phytium Root Rot were found to be insignificant and Peronospora destructor, Botrytis spp. and Puccinia porri fungal pathogens came to the fore. The chemicals fosetyl-Al, mancozeb+metalaxyl-M, mancozeb+mandipropamide, mancozeb, mancozeb+dimethomorph, maneb, ametoctradin+dimethomorph, copper sulfate+cymoxanil chemicals of isolates isolated from infected plants brought to the laboratory from the production areas were tested in vitro for their sensitivity. According to the ED50 values as a result of the probit analyzes in the trial, in fosetyl-Al chemical, Fusarium equiseti and Botrytis cinerea types, in mancozeb+metalaxyl-M, Botrytis cinerea and Stemphylium globuliferum types, in mancozeb+mandipropamid fungicide Botrytis cinerea, in mancozeb and maneb fungicides Stemphylium globuliferum, the least effect on the mycelial growth of Stemphylium vesicarium and Fusarium equiseti types fungi was determined in the mancozeb+dimethomorph fungicide, Botrytis cinerea, Alternaria infectoria and Stemphylium globuliferum types, in the ametoctradin+dimethomorph chemical in Fusarium equiseti and in the copper sulfate+cymoxanil double agent. As a result of the study, it is thought that producers should be made aware of fungal pathogens that are a problem in onion production areas. It has been tried to establish a direction for future control programs for other fungal pathogens that come after Onion Mildew and cause infection.