Abstract

The dodder (Cascuta campestris) and its host Clover (Trifolium alexandrinum) were studied under laboratory conditions to elucidate the effect of wastes aqueous extracts of two crops (Helianthus annus and Oryza sativa) and two weeds (pigweed; Amaranthus retrofluxus) and cockblebur; Xanthium stramirium ) common in the Egyptian fields. The allelopathic potential of allelochemicals of these plant wastes played an effective role on the germination and growth criteria of clover that reflected on dodder seeds germination and investment into its host. The results revealed that the used extracts reduced the germination percentage of dodder and its host slightly. Increasing in concentrations of waste extracts induced a great effect for all the utilized plant wastes. Inhibition in germination and growth criteria could be due to the presence of some allelochemicals as phenolics, flavonoids, alkaloids and sponins in the used waste extracts. It was noticed clearly that sunflower and pigweed waste extracts were more efficient than rice and cockblebur waste extracts in dodder and clover growth inhibition. The current study suggests availability of addition of waste plant extract for controlling of dodder in clover fields.

Key words: Trifolium alexandrinum, dodder (Cascuta campestris), weed control, Sunflower, rice, allelochemicals, phenolics, flavonoids, alkaloids, sponins