Abstract
Two pot experiments were performed in the greenhouse of the National Research Centre, Dokki, Giza, Egypt, during two successive summer seasons of 2014 and 2015 to study the Allelopathic potentiality of Eruca sativa (ESSP) and Raphanus sativus seed powder (RSSP) on the growth, yield of Helianthus annuus as well as associated narrow and broadleaved weeds Echinochloa crus-galli and Corchorus olitorius. Treatments were applied by incorporating seed powder of E. sativa (ESSP) and R. sativus (RSSP) to the soil at (0, 15, 30, 45 and 60g/kg soil). All ESSP as well as RSSP concentrations used minimized to great extent the dry weight of the two weeds at 60 days after sowing (DAS) and at the harvest. The highest reduction recorded with the highest concentration (60g/kg soil) of both material used. On the other hand, H. annuus growth and yield, yield components as well as oil content percentage were significantly increased with the most ESSP and RSSP concentrations used as compared to their corresponding mixed controls. The best results were recorded with ESSP treatment at 45g/kg soil and with RSSP at 30 g/kg soil concentration; these treatments achieved maximum increases over their corresponding control free from weed (Healthy). The allelopathic effect of ESSP and RSSP due to the presence of the allelochemicals: glucosinolates and phenolic compounds which play an important role in controlling the two annual narrow and broad-leaved weeds associating H. annuus and also increasing its yield.