The increase in the area of walnut plantings, which is now happening in Ukraine, is expected to activate pests and diseases for which the nut is the host.
Specialists from the Ukrainian Research Station for Plant Quarantine of IZR note that the belief that walnuts are not prone to disease and are avoided by pests exists in Ukraine because plantings lack phytosanitary surveillance.
This is not surprising, because about 83% of walnut trees grow in yards, where phytopathologists rarely pay attention to them.
Walnut Brown Spotting
Studies performed by specialists of the Ukrainian VAT of the Kyrgyz Republic in walnut stands of the Chernivtsi region during 2017-2019. showed the presence of 18 species of pathogenic fungi and one bacteriosis there.
Brown spotting caused especially great damage to the plants - its signs were found on almost all plants. The disease has a fungal nature, its causative agent is the fungus Gnomonia leptostyla (Fr.) Ces. Et be Not.
During the period of research on susceptible forms of walnut, the disease destroyed 50-75% of the crop. In particular, in trees affected by brown spotting, leaves fell prematurely, which caused the walnut kernel to darken and poorly fill.