Biocidal effects of dennettia tripetala, zingiber officinale and benlate on seedborne fungal pathogen (fusarium moniliforme) of watermelon (citrullus lanatus) varieties.

This study was carried out to investigate the effect of plant extracts, African pepper fruit (Dennettia tripetala) and Ginger (Zingiber officinale) on seed borne fungal pathogens of Watermelon (Citrullus lanatas) seeds. Watermelon seeds were extracted for seed health test using blotter paper method. The antifungal effects of ethanol and acetone extracts of the two plant extracts and synthetic fungicide were studied under in- vitro experiment against the seed borne fungal pathogen of Watermelon at 0%, 50% and 75%. It was a 3x3 factorial experiment at 5% Probability level laid out in a Completely Randomized Design experiment with three replications Ninety percent germination was obtained in the germination and seed health test of Watermelon seeds. Seed borne fungal pathogen (Aspergillus spp. and Fusarium spp.) were identified. The potential of these organisms for pathogenicity were tested using Kock’s postulate. The result of the pathogenicity test showed that Fusarium spp. was pathogenic. All plant extracts and Benlate inhibited the fungus (Fusarium moniliforme) in culture. The inhibition was also greater as concentration increased from 50% to 75%.  It was also observed that ethanol extraction solvent did better than acetone. Generally, Dennettia tripetala extract performed better than Zingiber officinale. It could therefore be recommended that the two plant extracts used in this investigation which were very effective in the control of Fusarium moniliforme of watermelon could be an alternative to the synthetic fungicide. It could also be suggested that further studies be carried out to isolate, identify, characterize and standardize the bioactive components of these phytochemicals in a bid to commercializing their production.