An experiment was carried out to evaluate the effect of aqueous and acetone extracts of Parthenium hysterophorus on causal organism of leaf blight of wheat (Alternaria triticina) under field condition. Plant growth characters of wheat (Triticum aestivum L.) were significantly enhanced with the application of aqueous and acetone extracts of P. hysterophorus. Although, maximum plant growth was noticed in acetone extract of both i.e. leaves and root. It also had significant effect on shoot and root length, dry weight of shoot, root and 1000 seeds weight over control. Aqueous and acetone extracts of leaves was lesser effect than root extract. Ratio of dry weight of shoot/root was maximum in case of aqueous extract of leaves, whereas, the minimum was observed in aqueous extract of Parthenium root. Effectiveness of the tested plant (P. hysterophorus) was also compared with known fungicide i.e. Dithane-M45.