TY - JOUR AU - Горган, Н. О. AU - Горган, М. Д. PY - 2013/08/15 Y2 - 2024/03/29 TI - Onion (Allium cepa L.) collection samples resistance of different ecological and geographic origin to downy mildew under Chernihiv region conditions JF - Plant varieties studying and protection JA - PVSandP VL - IS - 4(21) SE - VARIETY STUDYING AND VARIETY SCIENCE DO - 10.21498/2518-1017.4(21).2013.56798 UR - https://journal.sops.gov.ua/article/view/56798 SP - 25-29 AB - The article deals with performed investigation results of collection samples onions susceptibility of different eco- geographical origin to false mildew agent Peronospora destructor Berk. It is proved that the studied onion varieties and hybrids of first and second year of life are affected by false mildew annually, but with varying degrees of the disease development, depending on the infectious load, humidity and air temperature. Being carried on, investigations have shown that the disease spreading during three years in seed- plot of first year onions at the end of the vegetation season , according to the sample made 12,7–79,0 and its development – 8,0–61,7 %. False mildew has been spreading within 32,7–95,7 % and its development on natural provocative background made 25,7–88,3 % in mature growth phase of the seeds. Among the large number of studied samples, immune stable to the disease have not been identified. Chosen forms, having a relative field resistance to disease will be used in breeding programs for creating new varieties and hybrids. ER -