Melnichuk F. The basic diseases of an onions and a substantiation of protection ways against them in Forest-steppe conditions of Ukraine

The objects of studies. Pathogens of downy mildew, onion scab and bacteriosis of an onion, a sorts with different a degree of defeat, fungicides of the domestic and foreign manufacture. The purpose of studies. Studying of etiology of an onion diseases during vegetation of plants and storage of bulbs in Forest-steppe conditions of Ukraine and improvement of protection methods of this culture against pathogens of diseases of a fungus and bacterial origin. The methods of studies. Generally accepted in phytopa-thology, plant protection. Theoretical and practical re-sults. It was revealed the most widespread and dan-gerous diseases of a seed material. For the first time it was established, that system - contact fungicide Ri-domil Gold MZ 68 % WP stopped the diffusion devel-opment of Peronospora destructor (Berk) Casp pathogen in an initial stage of plant growth when dis-infected of a seed material of an onion. It was estab-lished optimum concentration of fungicides at soaking and injections of a seed material which effectively in-fluenced a degree of germination and development of bulbs.