Diagnostics, prevalence and harmfulness of the main cucumber diseases of gherkin type

Abstract

By examinations the phytosanitary condition of agrocenoses of cucumbers under open ground conditions, it was established that the main diseases symptoms on the plants in the field looked like spots, coating (sporulation or mycelium), rot, complete or partial wilting of plants. All these symptoms had the characteristic visual signs of damage (leaf apparatus, stems, fruits). During further incubation of the affected plant particles (selected herbarium material) in a wet chamber, the appearance of coating of mycelial hyphae on them indicated the fungal origin of the disease, exudate drops indicated the bacterial nature of the disease. The results of our research clearly showed that in the region of conducting research under open ground conditions on cucumber plants in recent years, the nature of the development and intensity of the main diseases spread is actively changing, in particular downy mildew – from moderate to strong, angular bacterial spot disease, anthracnose, powdery mildew – from moderate to depressive. However, we would like to note separately that today fusarium wilt should be added to the zonal list of potentially dangerous diseases of cucumber of Gherkin type in the open ground. All the above arguments allow us to draw a convincing conclusion that it is downy mildew that today annually occupies a dominant position in the zonal pathocomplex of open ground cucumber of the Left-Bank Forest-Steppe of Ukraine, which served as the main argument for choosing it as the main scientific object of our research.