Uneven ripening due to environmental stress or plant genetics is caused by one or more of the following factors
- Growing season too short for the affected crop. This may happen to tomatoes, eggplant, watermelon, gourds, and other long-season crops that are planted too late.
- Excessive shade and tight spacing may prevent plants from successfully ripening their fruits.
- Cool temperatures in late summer and early fall combined with diminishing daylight may prevent fruits from ripening fully. This is often observed in tomato and pepper crops. Cool-weather will also cause blotchiness and odd-colored patterns on fruits.
- Some cultivars may be more susceptible to uneven ripening. This is referred to as "green shoulders"