This study was conducted to evaluate the bioherbicidal properties of orange peels
against canary grass and cheese weed mallow and the response of common bean plants.
Two successive pot experiments were conducted with twelve treatments. The first four
treatments were applied by incorporating of orange peels powder with the soil surface at
successive rates (10, 20, 30 and 40 g/pot) one week pre-sowing of common bean. In
the other corresponding four treatments, the orange peels powder was incorporated with
the soil surface at the same rates but directly at the same time with sowing of common
bean seeds. Additionally, four untreated control treatments were applied for comparison.
The recorded results revealed the inhibitory allelopathic effects of orange peels powder
on both weeds with direct relationship between the orange peels rate and it's inhibitory
effects. However, the pre-sowing treatments were more effective than the others which
applied at the time of sowing. Orange peels at 40g/pot at one week pre-sowing gave the
highest inhibitory effect on both weeds. This superior treatment subsequently recorded
the highest growth parameters and yield traits of common bean. Estimated phenolic
compounds, flavonoids and essential oils in orange peels may be responsible for this
inhibitory effect.