Abstract:
In vitro studies were conducted to evaluate the effect of three plant extracts, Datura stramonium, Ricinus communis and Jatropha gossypifolia at 30, 50 and 65% concentrations and Copper (1) oxide in metalaxyl based synthetic fungicide (Trade name: Tandem®) on Colletotrichum lindemuthianum growth characteristics. The plants extracts were applied in situ to assess their efficacy in the management of anthracnose disease on cowpea. The results showed statistically significant (P<0.05) variations in C. lindemuthianum growth depending on the extract and concentrations. D. stramonium at 65% concentration was the best in reducing the growth of the fungus and disease incidence in the field. The effect of 65% D. stramonium compared favourably with the standard application rate of the synthetic fungicide. The growth rate of C. limdemuthianum treated with 65% of D. stramonium extract and Tandem® were not statistically different, both were approximately 2.9 mm day-1. Similarly, disease incidence was reduced by 14% in the plots where either the extract or Tandem® was applied. The study demonstrated that the active compound in the extract of D. stramonium can potentially replace synthetic fungicides in the management of cowpea anthracnose disease.
