Abstract:
Cabbage ring spot disease poses a significant threat to cabbage cultivation in
Nuwara Eliya and is traditionally controlled using environmentally harmful
chemical fungicides. In search of environmentally friendly alternatives, this
study aimed to identify the causative agent of the disease, potential
antagonists and plant extracts with antifungal properties. The isolated
pathogen Alternaria tenussima was comprehensively confirmed by
morphological and molecular methods, including a pathogenicity test.
Twelve fungal isolates were involved in in vitro experiments, seven of which
exhibited antagonistic effects against Alternaria spp. showed. Notably,
isolate 7 (I7) showed the highest inhibition. Transition to in vivo conditions
revealed significant differences between the fungal isolates and application
methods. Further investigations investigated the antifungal potential of the
nanoemulsion formulations with plant extracts, particularly cloves
(Syzygium aromaticum), cloves in combination with jasmine (Jasminum spp)
and nutmeg (Myristica fragrans). Among these formulations, combinations
of clove with jasmine and pure clove showed significant inhibition of
pathogen growth, especially at lower concentrations (50µL/10mL solidified
PDA). While this study lays the foundation, further investigation, including
gene sequencing, is imperative to confirm the identity of antagonistic fungal
strains. Furthermore, field evaluations are crucial to assess the field
effectiveness of both antagonistic fungi and plant extract formulations under
field growing conditions and to recommend sustainable agricultural
solutions to cabbage ring spot diseases.
