Field evaluation of the resistance of some faba bean (Vicia faba L.) genotypes to the parasitic weed Orobanche foetida Poiret

Heavy infestation of faba bean fields by Orobanche foetida is an emerging problem in Tunisia. Field trials during three consecutive crop seasons demonstrated the resistance of three genotypes to O. foetida, including the cv. Baraca, selected for resistance to O. crenata, and two Tunisian breeding lines, Bader and XBJ90.03-16-1-1-1. Resistant genotypes displayed a parasitism index two-fold lower than that of the susceptible checks. They carried 2–8 times less of tubercle attachments and 2–3 times less of emerged parasite spikes at pod setting stage and at crop maturity, respectively. Seed-yield losses by parasitism reached 90% for the susceptible checks and were two-fold lower for the resistant genotypes. Parasitism affected negatively the protein/starch ratio of seeds of both susceptible and resistant genotypes. The line XBJ90.03-16-1-1-1 was the best candidate for registration because of better productivity in non-infested fields and production of high-weight seeds.