Squash are often afflicted with this problem when they reach two to two and one-half inches long.
Affected areas are often the size of a quarter or larger, sunken and gray to black in color.
As this problem progresses, one-half or more of the fruit may be affected. The fruits ripen earlier and are usually worthless. This disorder is caused by a deficiency in calcium, a water-soluble element. The resulting dehydration of the cells explains the parchment-like appearance of the affected tissue. In some cases, the dead tissue is colonized by fungus producing a moldy appearance.