Abstract

Peniophora salaccae (Russulales, Basidiomycota), a newly identified pathogen of Salacca zalacca, is a major cause of snake fruit rot, resulting in significant agricultural losses. This study evaluates the efficacy of chemical fungicides and biological controls against P. salaccae SKRU002, focusing on disease suppression and fruit quality preservation. Commercial fungicides (propiconazole®, prochloraz®, metalaxyl®, azoxystrobin®, thiram®) and Streptomyces philanthi strains RM-1-138 and RL-1-178 were tested. In vitro, prochloraz® (1000 μL mL⁻¹) fully inhibited P. salaccae growth, outperforming other fungicides. Both S. philanthi strains exhibited strong antifungal activity through volatile and non-volatile compounds. Additionally, autoclaved (at 121 °C for 15 min) and diluted (1/1000) bacterial culture filtrates (BCF) from both strains achieved over 55 % inhibition of P. salaccae. In liquid culture, RM-1-138 (86.80 %) and RL-1-178 (80.86 %) demonstrated greater inhibition than metalaxyl® (9.34 %) and azoxystrobin® (56.84 %), though prochloraz® and propiconazole® remained the most effective (100 %). In vivo, untreated fruits inoculated with P. salaccae showed 100 % disease incidence, significant weight loss (13.28 %), color changes (L∗, a∗, and b∗), and reductions in total soluble solids, total phenolic content, and antioxidant activity, while titratable acidity remained unchanged. Both biological and chemical treatments effectively controlled the pathogen and preserved fruit quality. These findings highlight the potential of S. philanthi strains and fungicides in managing P. salaccae, offering promising strategies for snake fruit cultivation.