The pigment is produced after chlorophyll is destroyed due to environmental changes. Amounts of anthocyanin produced is dependent on stored sugar and fall sunlight.
The more stored sugar in the leaf and brighter the autumn days, the more intense red. Anthocyanin production also increases as phosphates moves out of the leaves; the lack of phosphates in young leaves in the early spring due to cool weather can also lead to the production of anthocyanin.
Plant genetics and heredity also have an effect on red colors.
See: Carotene; Chlorophyll; Tannin; Xanthophyll
Articles in this collection were copyrighted 1995 by the Board of Trustees of the University of Illinois. For full copyright information about the articles in this encyclopedia, click here.