Co-Authors:
Saks, Y., Golan Research Institute, University of Haifa, P.O. Box 97, Qatzrin, 12900, Israel
Barkai-Golan, R., Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
Abstract:
The antifungal activity of Aloe vera gel at 1-105 μl l-1 was tested on four common postharvest fruit pathogens: Penicillium digitatum, P. expansum, Botrytis cinerea, and Alternaria alternata. The natural gel suppressed both germination and mycelial growth with P. digitatum and A. alternata being the most sensitive species. Spore survival of P. digitatum, A. alternata, and B. cinerea was reduced by 15-20% at 1 μl l-1, but the gel was similarly effective against P. expansum only when the concentration exceeded 103 μl l-1. For the first two species, the suppressive effect of the gel increased with an increase in the concentration, culminating in 95% reduction in spore survival at 105 μl l-1. B. cinerea, however, responded with a partial germination recovery when the gel concentration was greater than 10 μl l-1. The inhibitory effect of the plant gel on colony growth was exhibited at 1 μl l-1, when a 67-69% reduction in radial growth was recorded for P. digitatum, A. alternata, and B. cinerea, and a 19% reduction for P. expansum after five days on potato dextrose agar (PDA) at 23 °C. The effect of the gel on disease development in P. Digitatum-inoculated grapefruit was expressed by both a delay in lesion development and a significant reduction in the incidence of infection following dipping in a concentration of plant gel of 103 μl l-1. © 1995.