Orobanche ramosa L. (broomrape) control in tomato (Lycopersicon esculentum Mill.) with chlorsulfuron, glyphosate and imazaquin

Chlorsulfuron, giyphosate and imazaquin were evaluated in pot and field studies for their efficacy in controlling broomrape (Orobanche ramosa L.) in tomato (Lycopersicon esculentum Mill.) in Northern Greece. All herbicides were applied four to five weeks after tomato transplanting, when the crop was at early flowering stage and broomrape had started to develop underground attachments. The number of emerged broomrape shoots and underground attachments were less affected by herbicide treatments than the dry weight, suggesting that the herbicides suppress the growth of broomrape rather than kill its underground organs. In the pot experiments, chlorsulfuron applied at 5 g AI ha^?1 was the most effective treatment for broomrape control and the least toxic to the crop. Imazaquin and glyphosate applied at 37 and 180 g AI ha^?1, respectively, controlled broomrape but imazaquin reduced crop yield. In the field, similar rates of glyphosate and higher rates of imazaquin were not toxic to the crop but were less effective on broomrape. Chlorsulfuron applied at 10 g AI ha^?1 controlled broomrape emergence by 88%. When the herbicide was applied twice (5+10 g AI ha^?1), it gave complete control of broomrape but delayed crop maturity. The yield of tomato was not increased as a result of these treatments because of low broomrape infestation and a short competition period.