Metadata
Enclosures (e.g., low tunnels) covered with
plastic films with medium to high sunlight
transparency (i.e., high transmissivity) can
significantly alter air temperature (Ta) and
have potential to increase crop yield. Low
tunnels are not only effective during early and
late in the growing season, but are also
effective during peak growing season to cool
crops (cover whitening), which would
otherwise experience excess heat stress.
Much like transparent polyethylene mulches
placed on the soil surface during the daytime,
low tunnels trap heat in the air that they
enclose, which increases Ta. During
nighttime, the effect of low tunnels on Ta is
reduced due to the absence of sunlight.
However, specialty plastics, such as
Thermax, have the ability to prevent
longwave or thermal radiation loss, much like
glass, and the associated heat keeps Ta
higher than for conventional polyethylene.
plastic films with medium to high sunlight
transparency (i.e., high transmissivity) can
significantly alter air temperature (Ta) and
have potential to increase crop yield. Low
tunnels are not only effective during early and
late in the growing season, but are also
effective during peak growing season to cool
crops (cover whitening), which would
otherwise experience excess heat stress.
Much like transparent polyethylene mulches
placed on the soil surface during the daytime,
low tunnels trap heat in the air that they
enclose, which increases Ta. During
nighttime, the effect of low tunnels on Ta is
reduced due to the absence of sunlight.
However, specialty plastics, such as
Thermax, have the ability to prevent
longwave or thermal radiation loss, much like
glass, and the associated heat keeps Ta
higher than for conventional polyethylene.
Audience
Commodity