Progress of Black Spot and Mycoparasitic Fungi in Papaya Genotypes Under Natural Inoculation Conditions

Papaya black spot, caused by Asperisporium caricae, is commonly accompanied by fungi with potential mycoparasitic activity, but their temporal occurrence across host genotypes is poorly understood. We monitored black spot and fungal colonization monthly for 12 months in ‘Golden’, ‘Maradol’, and ‘Sekati’ papaya plants established in a randomized complete block design with 10 replicates. Papaya black spot incidence, the incidence of leaves containing mycoparasitized lesions, total and mycoparasitism-associated disease severity, the proportion of non-colonized lesions, and the occurrence of fungal morphotypes were evaluated on intermediate and last fully expanded leaves. Repeated observations were analyzed using linear mixed models with genotype, evaluation time, and their interaction as fixed effects and block and plant as random effects. Evaluation time and the genotype × evaluation-time interaction were significant for all response variables, indicating that genotype differences varied among months. Disease severity discriminated genotypes more clearly than incidence, with ‘Golden’ generally showing greater severity, particularly on the last fully expanded leaf. Structures morphologically consistent with Hansfordia pulvinata and Acremonium-like fungi predominated and showed distinct temporal patterns. These results demonstrate pronounced temporal variation in disease, lesion colonization status, and fungal occurrence, but do not establish biocontrol efficacy. Culture-based and molecular identification, followed by controlled antagonism assays, is required before management recommendations can be made.