ON THE ISSUE OF FIELDS WEEDINESS WITH SEEDS OF BROOMRAPE (OROBANCHE CUMANA WALLR.), AN OBLIGATE PARASITE OF SUNFLOWER IN RUSSIAN FEDERATION THE REGIONS

Abstract

The high profitability of sunflower – the main oilseed crop in the Russian Federation, has led to a reduction in the period for its return to its original place in the crop rotation to 1-3 years. This led to the contamination of fields with the seeds the obligate sunflower parasite – broomrape (Orobanche cumana Wallr.), which capable of destroying the whole yield. The purpose of our work is to determine the race of broomrape seeds from the fields of some regions of the Russian Federation. Research objectives are to establish which races are present in the fields; to determine the most common of them; to identify regions where there are already broomrape biotypes that have managed to overcome the resistance of the currently cultivated sunflower assortment. Broomrape races were determined in samples of its seeds collected in 2020-2021 from 25 fields in six regions of the Russian Federation (Samara, Orenburg, Voronezh, Belgorod regions, Stavropol and Krasnodar regions). Most of the fields are dominated by race G broomrape, some are dominated by less virulent ones - E and F. The most virulent biotype (H) was found in the fields of all regions, except for the Alekseevsky district of the Belgorod region. Monitoring of the broomrape seeds race from sunflower fields is relevant for the correct placement of the assortment and will slow down the formation of highly virulent parasite biotypes in each field. The necessity of replacing the sunflower assortment of foreign selection cultivated in the Russian Federation with varieties and hybrids of domestic production is discussed.