Catfacing (photo above left) is a tomato disorder that causes fruits to become distorted and puckered; bands of tan or gray scar tissue run across the surface. Symptoms are often most pronounced at the blossom end. It occurs when conditions such as cold weather (below 55oF), hot weather (above 85oF), or drought interfere with flower and fruit development. Growth cracks in tomato skin may be radial (as in the photo above right) or concentric. Rot may set in at the cracks or they may heal over with corky, brown tissue. It is often more of a problem when weather is wet or plants are watered heavily as the fruits ripen, especially after a period of dry weather.
Protect plants from cool temperatures with floating row covers or cloches. Keep soil uniformly moist throughout the growing season. Hybrid varieties are less susceptible to catfacing. Choose crack-resistant varieties.
Photo courtesy of David Liebman