October rains and winds have blown down the leaves on many old “wild” apple trees here, but many trees continue to hold tightly onto all or some of their apples. The curious result is that we see gnarly gray trunks and branches decorated with green and red fruit like Christmas lights.
The dropping of an apple apparently is not a simple matter. As we understand it, apples usually are dropped twice a year. Some are shed in the summer when the tree decides to drop (“abcises”) a number of its immature apples to preserve energy that will be used to help the rest of the fruit mature. As the days get colder in the fall or early winter, the tree eventually will drop its mature fruit.
The process apparently involves the apple stem cells secreting enzymes that eat away their cellular walls. This weakens the stems’ grips and, eventually, gravity causes the fruit to fall, perhaps on a physicist’s head as the story goes. Warm and wet weather here may have slowed the process. (Images taken in Brooklin, Maine, on October 14 [full tree] and 5 [branches], 2021.)