Antifungal activities of <i>Carica papaya</i> and sodium bicarbonate against Soybean fungi

Abstract

Soybean (Glycine max (L.) merr.) is a well-known leguminous crop serving as a principal protein rich food source for human and livestock. The study examined the antifungal efficacy of sodium bicarbonate (NaHCO₃) and Carica papaya on fungi isolated from soybean seeds. The inhibitory effects of sodium bicarbonate (NaHCO₃) and leaf extracts of Carica papaya were tested on three fungi. In vitro studies were carried out on Potato Dextrose Agar (PDA) for fungal isolation from soybean seeds and for the control of the pathogens using NaHCO₃ and C. papaya. The results obtained were compared with benlate (a.i 50% Benomyl); a synthetic fungicide. Aspergillus niger had the highest percent occurrence (50%) followed by F. ventricosum (33%) and then B. theobromae (17%). The percent fungal inhibition was highly significant at 1% level of probability, indicating that all the antifungal agents exhibited broad spectrum inhibition against the isolates. Benlate completely (100%) inhibited the three pathogens. There was no significant difference (P ≤ 0.05) in the inhibition of A. niger at 1.54 mg/ml of C. papaya and 3 mg/ml of NaHCO₃. Fusarium ventricosum and B. theobromae were best inhibited at 1.54 mg/ml of C. papaya with mean values of 95.63% and 95% respectively. A positive and significant correlation occurred between the inhibitions of all the fungal isolates. This implies that all the antifungal agents are capable of inhibiting the three fungal isolates. The study suggests that C. papaya and NaHCO₃ are capable of controlling seed-borne pathogens in soybean seeds.

Keywords: Antifungal agents, inhibition, leaf extract, mycelia growth, seed-borne fungi.