Current research strategies for sunflower broomrape control in Spain

Sunflower broomrape (Orobanche cumana Wallr) continues to be one of the most important constraints in sunflower production in Spain. In the last ten years, genetic resistance has been the predominant control strategy against O. cumana. However, the introduction of new resistance genes has been frequently followed by the occurrence of new virulent races overcoming their resistance. In this report, a combined control strategy against O. cumana is discussed, including: a) the use of IMI sunflower cultivars to control winter and early spring weeds and sunflower broomrape; b) the combination of vertical and horizontal resistance mechanisms in the same genotype, supported by molecular markers in order to develop a more durable resistance; c) the study of the variability and racial composition of Spanish sunflower broomrape populations using classical and molecular approaches with the objective to learn about population dynamics in this parasitic weed. The combination of such strategies is expected to contribute to improved sunflower performance in areas infested by broomrape in the Mediterranean area.