Allelopathic effect of aqueous extracts of major weed species plant parts on germination and growth of wheat

Abstract

A laboratory experiment was conducted at Plant Protection Research Center, Ambo to assess allelopathic effect of aqueous extracts of Amaranthus hybridus, Parthenium hysterophorus, Datura stramonium and Argemone mexicana leaf, stem and root parts on seed germination, seedlings growth and biomass production of wheat cultivars; HAR-1685 and Durum wheat. Aqueous extracts at 1 g/ml ratio concentrations were prepared for each weed species plant parts uniformly and applied to seeds placed sparsely in petri dish. Highest wheat seed germination reduction (22%) was caused by leaf extract of P. hysterophorus. Uniformly more inhibition on radicle length of wheat seedlings was observed with leaf extracts of the test weed species than the other plant part extracts. Plumule length of the wheat seedlings were reduced by 60 and 40% due to leaf extracts of P. hysterophorus and A. hybridus. In general, the investigation showed that P. hysterophorus and A. hybridus plant leaf and stem extracts consistently cause considerable reduction on percent seed germination, respectively. In addition, leaves extract of both weed species gave the highest negative effect on radicle and plumule elongation of the seedlings. Thus, farmers shall be advised to give special attention in avoiding or minimizing those weed species from farm to contain their adverse effects on the crop.