Codification and description of growth stages in guava (Psidium guajava L.) using the extended BBCH scale

In recent years, there has been a growing interest in extending the production calendar for guava (Psidium guajava L.) by cultivating it outside traditional growing areas. Since guava is very sensitive to environmental factors, such efforts often disrupt the regularity of cropping due to changes in phenological patterns. The lack of an universally accepted and standardized phenological scale for guava represents a significant limitation for an accurate description and comparative analysis of its developmental stages. In the present study, the flowering development of guava was characterised systematically and placed in context with the BBCH scale of Biologische Bundesanstalt, Bundessortenamt, and Chemische Industrie. For this objective, phenological development of Lucknow-49 guava variety was recorded over two consecutive years. The observations regarding phenology were precisely matched with the BBCH coding system thereby allowing the integration of floral developmental stages within its major growth stage classes. Standardization in methodology in this regard provides a strong, consistent framework that allows better comparability and reproducibility of results in the phenology of guava.