Garden with Insight v1.0 Help: Plant next day functions: figure if have died from frost
At this point in the plant next-day routine annual plants determine
whether they have died from frost overnight. If there is no snow on the soil patch, the plant dies if the
combined frost and day length damage factor exceeds 0.9 (as an arbitrary cutoff). Snow insulates the plant
from the air temperature, so (using an S curve function) the number
compared to the frost kill cutoff of 0.9 is reduced with increasing depth of snow.
In the EPIC model not much attention is paid to the demise of annual
plants since annual crop plants are usually harvested before they get a chance to die. We added an extra
absolute temperature cutoff to make sure annual plants die off if the weather is cold. If the mean temperature for the day falls below the absolute frost cutoff, which is
a plant parameter, the plant dies. Of course, adding a parameter is easy
but finding the right values for different plants is more difficult. All of the plants in our data for this
version use the same cutoff of -3 degrees C.
If the plant has died from frost, it leaves the plant next-day routine at this point.
calculation of damage from frost and short day length
EPIC Winter Dormancy (includes frost and day length damage)