Zippering are thin scars running from the top of the shoulder of the fruit down the length to the blossom end. These longitudinal scars have small transverse scars along it, which resemble a “zip” (thus the name). More than one of these scars can appear on the fruit. Zippering should not be confused with spider track (see spider track) or cat face.
Causes of zippering
Zippering is basically a pollination problem caused by excessive high humidity. Anthers become attached to the ovary wall of the newly forming fruit which cause zippering. It can occur under most weather conditions but is more pronounced in cooler weather.
- Use resistant varieties.
- Excessive pruning should be avoided
- Too high nitrogen in the medium due to decomposing of growth medium can also increase the risk of zippering.