Tomato stitching or zippering occurs when a thin, brown, necrotic scar that extends from the stem scar all the way to the blossom end appears on fruit. The longitudinal scar has small transverse scars along it, making it resemble a zipper or seam. Fruit can have one or several scars. This disorder does not affect the edibility of the fruit, but may render the fruit unmarketable.
Cause
Stitching/Zippering is caused by anthers (the pollen-producing flower part) that are attached to the ovary wall of a newly forming fruit. This disorder occurs more frequently in cool weather.
Management
- Plant varieties that are less susceptible to stitching/zippering
- Avoid low greenhouse temperatures
--Adapted by G. Higgins, from “Zippering”, J.W. Scott, Compendium of Tomato Diseases and Pests, 2nd ed., eds, J.B. Jones, T.A. Zitter, T.M. Momol, and S.A. Miller.