The allelopathic potential of aqueous extract of air-dried olive processing waste (OPW) at four concentrations (1.0, 3.0, 6.0, and 9.0% w/v) on grain germination and seedling growth of Zea mays was studied under laboratory conditions. The germination of corn grains showed a relative tolerance to OPW aqueous extract. Increasing the concentration of OPW extract up to 3.0 % significantly improved the biomass of radicle and plumule thereafter; the fresh and dry weights were significantly reduced. A parallel result obtained for accumulation of soluble sugars and proteins. Thus, the effect of OPW aqueous extract may be promotive or inhibitory depending on the used concentration.
Allelochemicals, Biomass, Germination, Olive processing waste, Proteins, Sugars, Zea mays.