Abstract

The objective of the present study was to assess the anti-fungal activity of medicinal plant extracts on inhibition of Colletotrichum gloesporioides mycelial growth, sporulation and germination and on anthracnose control in Heliconia psitacorum cv. Golden Torch and Heliconia rostrata. Extracts of garlic, lemon grass, cinnamon, lemon balm, eucalyptus, ginger, mint, bitter melon and black pepper were used. The, mycelial were assessed in vitro by measuring their growth in Petri dishes. Sporulation was assessed by counting spores in a Neubauer chamber. Germination was observed based on germination tube emission. In the in vitro tests, the inflorescences were treated with the plant extracts and inoculated with the pathogen 24 h later. The results showed that all the extracts presented anti-fungal activity, in greater or lesser intensity, compared to the control. The garlic extract resulted in the highest mycelial growth inhibition rate. Regarding sporulation, the bitter melon, ginger, mint, popcorn eucalyptus and bitter melon extracts were more efficacious, interfering in spore formation; while the ginger extract most reduced spore germination inhibiting germination tube emission. For the in vivo tests, it was observed that all the plant extracts tested were efficient in reducing lesion severity in the inflorescence, showing that the use of plant extracts may be a promising alternative for managing the diseases that affect helconia post-harvest.

Key words: Alternative control, fungi, Colletotrichum gloesporioides, tropical flowers.