Optimizing soil-applied silicon concentration for enhanced growth in green chili (Capsicum annuum L.): A seasonal analysis

Green chili (Capsicum annuum L.) is a widely cultivated spice crop of high economic importance, playing a vital role in both global and Sri Lankan agriculture. Several factors influence the growth of green chili, and this study aimed to determine the optimal silicon (Si) concentration required to maximize its growth. The effects of two cultivation seasons (“Yala” and “Maha”) and different Si concentrations (0–300 ppm) were evaluated. Growth parameters assessed included leaf Si accumulation, plant height, number of leaves, number of pods per plant, average pod weight, pod diameter, and pod length. Univariate and multivariate statistical analyses were performed using a full factorial design with six replicates per treatment combination. The results revealed that both season and Si concentration had a significant impact on growth parameters. MANOVA results indicated that season, Si concentration, and their interaction had a significant overall effect on the combined set of growth traits. Univariate ANOVA further showed that Si concentration significantly affected all growth parameters, while season and the interaction effect influenced several traits. The optimal Si concentration was identified as 200 ppm, consistently producing the highest and most significant growth responses compared to other levels. The availability of Si in the soil solution, influenced by soil pH, was crucial for effective Si absorption. Therefore, considering soil pH is essential when determining the optimal Si content to promote plant growth. Overall, this study provides valuable insights into the interactions between seasonal variation, Si levels, and green chili growth, contributing to the development of improved cultivation strategies for enhanced yield and quality.