Stimulating effect of the root exudates of sorghum, millet, and Sudan grass on the seed germination of broomrape (Orobanche cumana Wallr.) infesting sunflowers in Russia

Broomrape (Orobanche cumana Wallr.) is a harmful obligate parasite of sunflower. We found that the negative effect of broomrape on the cultivation of this crop can be eliminated by planting the crops that stimulate the germination of broomrape seeds but do not serve as its hosts. Under laboratory conditions, the root exudates of eight samples of grain sorghum, three samples of sugar sorghum, two samples of Sudan grass, and five cultivars of common millet stimulated the germination of broomrape seeds in different ways. It was observed that Gureeva millet, Sudan grasses Anastasia and Aleksandrina, grain sorghum Khasine 28, and sugar sorghum Listvenit are the most suitable provocative crops for the elimination of O. cumana seeds.