Spreading and virulence of broomrape in Rostov region

The sunflower crops in 43 districts of Rostov region were inspected for the purpose of exposure of their weeding degree by broomrape (Orobanche cumana Wallr.). It was shown 14 districts have a high and a mid degree of fields weeding by broomrape. It was carried out the test of virulence 18 broomrape populations from Rostov region and some other areas with respect to sunflower line differentiator: 7, 202, LC1002, LC1003, LC1093, 16Ах25, и P 96. There are populations where race D prevails (in districts Salsky, Tselinsky, Sholochovsky, Rodionovonesvetaisky from Rostov region and Eisky - Krasnodar region). It was revealed race E (in districts Konstantinovsky, Tsimlyansky from Rostov region and Kanevskoy - Krasnodar region). Widely race F is presented (in districts Konstantinovsky, Millerovsky, Morozovsky, Tsimlyansky from Rostov region, in both populations from Volgograd region and Svetlogradskaya - Stavropol region). Especially districts Belokalitvinsky, Egorliksky, Konstantinovsky, Tatsinsky from Rostov region are not satisfactory owing to the presence a big portion of biotype overcoming the differential resistance to race G. This fact is not let to show there the presence of other races. This biotype presents in other studied populations except ones from Salsky and Tselinsky districts of Rostov region.