Broomrape {Orobanche cumana Walk.) on sunflower and methods of its control

Sunflower is higher profit crop and can prove all needs of the Russian Federation in oil. But the important factor limiting sunflower cultivation in the southern regions of the Russian Federation is weed broomrape (Orobanche ситапа Wallr.) - an obligate parasite. There are shown the cause-and-effect relations of speed-up formation of new broomrape races and quick infestation of soil with seeds of the most virulent biotypes of broomrape. The main reasons of imbalance in biocenoses of sunflower - broomrape on the south of the country after dissolution of the USSR are permission to import into the Russian Federation seeds of foreign breeding susceptible to the local broomrape as well as intensification of crop cultivation and reduction of theoretically based crop rotation till 1-3 years. Violation of laws of biological communities’ coexistence and misunderstanding of regularities of relations between parasite and its host leads to the situation when sunflower cultivation on fields infested with broomrape seeds becomes unprofitable for farmers and it is necessary to clean soil of broomrape seeds. A complex of measures directed on a slow-up of broomrape race development in sunflower sowings and decreasing of broomrape seeds storage in soils is proved.