Light intensity was measured every two weeks after film application at four fixed
sites inside the tree canopy (1.5 mabove ground and at themid-point of the radius of
the tree canopy on a horizontal plane) around noontimewhen the sky was clear.ALICORQuantumSensor (LI-COR, Lincoln,NE) was used and was oriented downward
fromthe tree to measure light reflected fromthe ground. The foil filmhad the highest
light reflection, about 85% in ultra violet (UV), 75% in visible wavelength (400±
700), and 87%in far red (FR). The poly film had the lowest light reflectionwith about
40%inUV, 35%in visiblewavelength, and 42%in FR. Light reflection bymetalized
film was 75%in UV, 60%in visible light, and 65%in FR. Natural daylight intensity
was also measured at the same time. After film application, light intensity inside the
tree canopy increased from about 30% daylight to 68% (foil film) and 50%
(Metalized film) daylight, respectively. Poly film did not increase light intensity.
Light intensity inside the tree canopy remained relatively constant during eight
weeks after film application.