The BBCH-scale (sunflower) identifies the phenological development stages of the sunflower (Helianthus annuus). It is a plant species specific version of the BBCH-scale.
Phenological growth stages and BBCH-identification keys of sunflowerCodeDescriptionPrincipal growth stage 0: Germination00 Dry seed (achene)01 Beginning of seed imbibition03 Seed imbibition complete05 Radicle emerged from seed06 Radicle elongated, root hairs developing07 Hypocotyl with cotyledons emerged from seed08 Hypocotyl with cotyledons growing towards soil surface09 Emergence: cotyledons emerge through soil surfacePrincipal growth stage 1: Leaf development110 Cotyledons completely unfolded12 2 leaves (first pair) unfolded14 4 leaves (second pair) unfolded15 5 leaves unfolded16 6 leaves unfolded17 7 leaves unfolded18 8 leaves unfolded19 9 or more leaves unfoldedPrincipal growth stage 3: Stem elongation30 Beginning of stem elongation31 1 visibly extended internode32 2 visibly extended internodes33 3 visibly extended internodes3 . Stages continuous till ...39 9 or more visibly extended internodesPrincipal growth stage 5: Inflorescence emergence51 Inflorescence just visible between youngest leaves53 Inflorescence separating from youngest leaves, bracts distinguishable from foliage leaves55 Inflorescence separated from youngest foliage leaf57 Inflorescence clearly separated from foliage leaves59 Ray florets visible between the bracts; inflorescence still closedPrincipal growth stage 6: Flowering61 Beginning of flowering: ray florets extended, disc florets visible in outer third of inflorescence63 Disc florets in outer third of inflorescence in bloom (stamens and stigmata visible)65 Full flowering: disc florets in middle third of inflorescence in bloom (stames and stigmata visible)67 Flowering declining: disc florets in inner third of inflorescence in bloom (stames and stigmata visible)69 End of flowering: most disc florets have finished flowering, ray florets dry or fallenPrincipal growth stage 7: Development of fruit71 Seeds on outer edge of the inflorescence are grey and have reached final size73 Seeds on outer third of the inflorescence are grey and have reached final size75 Seeds on middle third of the inflorescence are grey and have reached final size79 Seeds on inner third of the inflorescence are grey and have reached final sizePrincipal growth stage 8: Ripening80 Beginning of ripening: seeds on outer third of anthocarp black and hard. Back of anthocarp still green81 Seeds on outer third of anthocarp dark and hard. Back of anthocarp still green83 Dark of anthocarp yellowish-green, bracts still green. Seeds about 50% dry matter85 Seeds on middle third of anthocarp dark and hard. Back of anthocarp yellow, bracts brown edged. Seeds about 60% dry matter87 Physiological ripeness: back of the anthocarp yellow. Bracts marbled brown. Seeds about 75–80% dry matter89 Fully ripe: seeds on inner third of anthocarp dark and hard. Back of anthocarp brown. Bracts brown. Seeds about 85% dry matterPrincipal growth stage 9:92 Over ripe, seeds over 90% dry matter97 Plant dead and dry99 Harvested product
1 Stem elongation may occur earlier than stage 19; in this case continue with the principal stage 3
References
External links A downloadable version of the BBCH Scales