Beam light interception by twisted leaf surfaces

✍ Scribed by J.-F. Ledent

• Publisher: Elsevier Science
• Year: 1976
• Weight: 506 KB
• Volume: 17
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(76)90031-5

✦ Synopsis

Formulae allowing the calculation of the shadow projected by a twisted leaf surface (helicoid) on a plane perpendicular to the sun's rays have been presented. The effect of leaf twisting on beam light interception in plant canopies is discussed. The effect of leaf twisting is similar to the effect of an increased erectness of the canopy. It is the greatest at high sun angles, and with droopy canopies. The increased erectness may be quantified considering the leaf angle ~ of an equivalent but untwisted canopy which should intercept the same amount of beam light. The increased erectness is then the difference between (~ and leaf midrib angle. It is roughly independent of sun angle, but varies from about 45 ° to 0 . . . o o 0 with leaf midrib angle (to the horizontal) varying from 0 to 90 .