Chemical Control of Broomrape (Orobanche aegyptiaca) in Tomato (Lycopersicon escolentum) by Glyphosate and Sulfosulfuron

For investigating of O. aegyptiaca control in tomato with sulfosulfuron and glyphosate and evaluating the efficacy، dose and time of application، some studies were conducted in 2011 at Aarhus university of Denmark. At first، the efficacy of sulfosulfuron (0. 029، 0. 147، 0. 735، 3. 676 and 18. 378 mg per lit) and glyphosate (0. 023، 0. 117، 0. 587، 2. 935 and 14. 676 µl per lit) on Egyptian broomrape seeds were tested in vitro without a host plant by using of GR24. Then، the efficacy of these herbicides for broomrape control in two varieties of tomato (Viva and Hyb. Petopride II) in greenhouse conditions was investigated. Treatments in greenhouse experiments were four doses of sulfosulfuron (25، 50، 75 and 100 gr ai/ha) and glyphosate (20، 40، 60 and 80 gr ai/ha) at one، two and three application. First application was conducted 15 days after tomato seedlings transplanting and the time between two applications was 14 days. Results of Petri-dish experiment showed that both herbicides significantly reduced radical length of broomrape seeds compared to the untreated control. In pot experiments، two tomato varieties responses to herbicides were different. Viva cultivar was better than Hyb. Petopride II Cultivar in both herbicide applications. Sulfosulfuron at doses of 50 gr ai/ha (one، two and three times of application) and 25 gr ai/ha (two and three times of application) viva cultivar were the best treatments for broomrape control and producing tomato biomass. Also، glyphosate at doses of 20 and 40 gr ai/ha (one، two and three times of application) in this variety was safe for tomato and controlled broomrape. Sulfosulfuron was a safer herbicide than glyphosate for broomrape control in tomato