Nano silica spray increase Phalaenopsis pulcherrima growth and resistance against Dickeya dadantii infection

Abstract

Soft-rot disease because of Dickeya dadantii infection has hampered orchid production in the tropics. Induced resistance using nano-silica may be used to control the soft-rot disease. Nano-Si increases resistance by forming a silica layer on the plant epidermis. Nano-Si has a larger surface area. This study aims to determine the appropriate concentrations of silica to induce resistance to D. dadantii in Phal. pulcherrima. The experiment was set up in a single factor trial and various nano-Si concentrations (0, 7.5, 15, 22.5 and 30 ppm) with an application interval of 3 days for 120 days. The application volume was 4 mL per plant. Each treatment was repeated three times. Statistical analysis was done using ANOVA and mean comparison using LSD. After inoculation with D. dadantii, leaf of Phal. pulcherrima was observed for 48 HPI. The results showed that plant treatment with nano-Si at 30 ppm caused the slowest expansion of the soft-root symptom diameter compared to other concentrations. Si is a promising compound to increase Phal. pulcherrima growth and resistance against D. dadantii infection.