Effects of applying cold and hot aqueous extracts of ginger to control onion rot disease caused by Aspergillus niger

Abstract

Current study aimed to evaluate the efficiency of applying cold and hot aqueous ginger extracts to control onion rot disease caused by Aspergillus niger. We observed significant effect of the cold aqueous ginger extract on reducing the averaged A. niger growth on PDA culture medium and also the decreased average of onion spoilage when dipping in this extract as it exceeded hot aqueous extract. Results showed that there was an inverse relationship between the concentration of ginger and the growth of the pathogenic fungus either on PDA or the average of onion spoilage when it dipped in both extracts. The elevated concentration of ginger extract, decreased its effect on A. niger and vice versa, as the low concentration of ginger extract was significantly exceeded the high concentration in the reduction of the growth of pathogenic fungus when 5 g L-1 resulted in 5.10 and 5.20 cm reduction for cold and hot extracts respectively. Using 30 g L-1 exhibited a reduction in the growth of fungus amounted to 6.45 and 6.70 cm for cold and hot extracts respectively.

Keywords

• aspergillus niger
• onion
• ginger
• cold and hot aqueous extracts