Alternariosis or brown spot of pomegranate bushes in the western part of Azerbaijan

Abstract

Alternariosis or brown spot (Alternaria alternata (Fr.) Keissl.) is a widespread disease of pomegranate bushes in Azerbaijan. The disease occurs mainly in the western part of the country. Alternariosis or brown spot on pomegranate bushes (Alternaria alternata (Fr.) Keissl.) is found mainly on leaves and fruits. On ripening pomegranate fruits, the lesion begins with small brown or black spots that increase in size and become round or oval. The causative agents of alternariosis or brown spot on pomegranate bushes (Alternaria alternata (Fr.) Keissl.) are imperfect fungi of the genus Alternaria, from the order Hyphomycetales; Alternaria alternata (Fr.) Keissl is more common in the conditions of the western part of Azerbaijan. Alternariosis or brown spot (Alternaria alternata (Fr.) Keissl.) causes the greatest harm in conditions of sufficient moisture.
The aim of the article is to present the results of studies on the distribution, intensity of development and harmfulness of alternariosis or brown spot of pomegranate bushes (Alternaria alternata (Fr.) Keissl.), as well as biological effectiveness of fungicides used to control alternariosis, in the western part of Azerbaijan. Research methods used are generally accepted in phytopathology and plant protection to identify and record the infectious potential of the causative agent of alternariosis or brown spot of pomegranate bushes (Alternaria alternata (Fr.) Keissl.) as well as to disease monitoring. During field studies, the fungicides used were 0.4% Selphate (37.5% copper oxychloride + 16% zineb), 0.05% Azoxifene (20% azoxystrobin + 12.5% difenoconazole), 0.05% Conazole (25% difenoconazole) and 0.3% P-oxiride (50% copper oxychloride) and determined their biological effectiveness accordingly.
In the last 5 years, there has been a trend of increasing harmfulness of alternariosis or brown spot of pomegranate bushes (Alternaria alternata (Fr.) Keissl.) in the western part of Azerbaijan. As our research results show, brown spot mainly affected the leaves of pomegranate bushes. Damage to pomegranate fruits differed only in certain years in the studied gardens. During field studies, it was found that the 0.4% fungicide Selphate gives the best results.