Phenological Growth Stages of IAbelmoschus manihot/I: Codification and Description According to the BBCH Scale

Abelmoschus manihot L. (A. manihot) has received more and more attention due to its potential edible and medicinal value. It shows higher yield and related fine agronomic traits suitable for disadvantaged areas and low-input planting. However, a systemic description of the phenological growth stages of A. manihot, an alternative, multipurpose crop of worldwide interest, does not exist. This study aims to detail the phenological growth stages of A. manihot based on the BBCH scale. Nine principal growth stages were described from seed germination to senescence, along with 69 secondary growth stages, including germination, leaf development, formation of side shoots, primary stem elongation, inflorescence emergence, flowering, fruit development, maturation of fruit and seed, and senescence. However, the morphology and structure of A. manihot become complex with growth, and some growth stages, like inflorescence development, flowering, fruit development, and fruit maturation, overlap totally or partially with each other. Thus, the three-digit scale is considered necessary for a complementary description of these growth stages and illustrations for clarification. Moreover, the unique morphology and structure features of the pistil, stamen, and ovary and the development process of fruits and seeds were described in detail at different stages. The basic and extended BBCH scales will add new information on defining and identifying A. manihot phenological growth stages. They will help farmers efficiently schedule and manage A. manihot cultivation and improve knowledge dissemination among growers and researchers.