Assessing the Performance of Maize (Zea mays L.) as Trap Crops for the Management of Sunflower Broomrape (Orobanche cumana Wallr.)

Sunflower broomrape (Orobanche cumana Wallr.) is a weedy root parasite that causes huge damage to sunflower (Helianthus annuus L.). Trap crop can stimulate parasitic seed germination without attachment in trap crop, and it was considered as economic methods for controlling the parasite. In this study, co-culture and pot experiments were conducted to assess the allelopathic activity of maize (Zea mays L.) to stimulate broomrape seeds germination and to evaluate the performance of maize rotation for reducing sunflower broomrape infection. All the tested maize cultivars could induce sunflower broomrape germination, and the most active maize cultivar was N314, which induced approximately 40% broomrape seeds germination. Rotation of maize significantly reduced broomrape infection on subsequent sunflower and increased sunflower biomass. After cultivated N314 for 3 years, broomrape attachment on sunflower was the lowest (0.8 attachment plant(-1)), and the dry mass of sunflower shoot (28.7 g plant(-1)) was approximately twice higher than the sunflower without previous crop. The effectiveness of broomrape management was significantly different among various maize cultivars. Meanwhile, the differences among cultivars were decreased with the years of maize cultivated prolonged. Our results confirmed that maize was significantly effective in reducing the sunflower damage caused by sunflower broomrape and suggested that maize rotation could be included in the integrated management of sunflower broomrape.