Virulence of sunflower broomrape populations in regions of the North Caucasus
At the last years the more information is forthcoming from different districts about strong affection by broomrape of assortment having the immunity. The new virulent broomrape races: F, G, H were revealed in European countries cultivated a sunflower. It was shown the broomrape Svetlogradskaya from Stavropol region and Morozovskaya from Rostov region are the most aggressive.