Investigation on response of Egyptian broomrape (Orobanch aegyptiaca) seed to different plants

Broomrape is a parasitic weed that reduces the yield of many plants. In this study, in the liquid culture conditions in the laboratory, broomrape seed germination and connection to the roots of some crop plants were evaluated. In the greenhouse, effect of these plants under intercropping and rotation with tomatoes was also evaluated on broomrape germination. In the laboratory cotton (Gossypium hirsutum), sunflower (Helianthus annuus), soybean (Glycine max), hairy vetch (Vicia villosa), mung bean (Vigna radiate) and alfalfa (Medicago sativa) and in the greenhouse in addition to aforesaid crop plants, wheat (Triticum aestivum), barley (Hordeum vulgare) and rye (Secale cereale) was also used. Tomato (Lycopersicum esculentum) was used as a control. In the laboratory, the broomrape seed germination rate by all plants that were tested was 10 to 70 percent. In tomato, cotton and sunflower, the rate of connection was more than germination rate. Alfalfa, soybean, mung bean and hairy vetch acted as a trap or catch crop, but alfalfa did not show any connection, and in soybeans, mung bean and hairy vetch broomrape germination rate was much more than connection rate. Greenhouse results showed that cotton and sunflower in intercropping reduced broomrape stem number, but in rotation increased the tubercles number of tomato roots. Soybean, mung bean and hairy vetch relative to other plants, in intercropping stimulated broomrape stem and tubercle production on tomato roots and alfalfa in rotation increased the number of tubercle. It seems broomrape germination response to different plants vary depending on environmental conditions. In both intercropping and rotation systems, all of the plants reduced the dry weight of broomrape. The decline in intercropping was between 25 and 95 percent and in the rotation was between 31 to 57 percent. Grass species in intercropping system had a significant impact on reducing the number and dry weight of broomrape plants, but on the other hand led to a high reduction in dry weight of tomato root and shoot. However, grass species in rotation, reduced the dry weight of broomrape, but it did not show a decreasing effect on tomato dry weight. According to the results, it seems that the use of plants as traps or catch crop to reduce germination broomrape can be included in the system of integrated management of broomrape control.