Triggering and Enhancing Seedling Growth in Mangosteen using Microbial Consortium in Combination with Foliar Nutrition

Abstract

Slow juvenile growth limits nursery establishment of mangosteen (Garcinia mangostana L.). This study evaluated microbial consortia and foliar NPK nutrition, individually and in combination, for improving seedling growth under rain-shelter pot culture. Three-month-old seedlings were arranged in a completely randomised design with seven treatments and three replications, using 210 seedlings. Treatments included PGPR Mix-1, arbuscular mycorrhizal fungus Glomus fasciculatum, foliar NPK (3:1:1) at 0.5%, their combinations, Arka Microbial Consortia (AMC), and an untreated control. Growth was recorded at two-month intervals for eight months, while photosynthetic pigments, biomass, root traits, microbial root infection, mortality, and survival were assessed at the end of the study. The combined treatment T5 [PGPR Mix-1 + G. fasciculatum + foliar NPK] consistently produced the highest values for major growth, leaf, pigment, biomass, and root parameters. At eight months, T5 recorded a plant height of 11.38 cm, stem diameter of 3.60 mm, total leaf area of 289.31 cm², total chlorophyll of 1.330 mg/g, carotenoids of 0.301 mg/g, and root length of 20.70 cm. T5 also recorded 40% microbial root infection, 3.33% mortality, and 96.67% survival. AMC (T6) was generally the next-best treatment. These findings indicate that combined microbial inoculation and foliar NPK nutrition can enhance early mangosteen seedling performance under the tested nursery conditions.