Dramatic fluctuations in soil moisture can cause tomatoes to develop cracks in the stem end of the fruit. These cracks may be radial or concentric; rot may set in at the cracks, or the cracks may heal over with corky, brown tissue. Heirloom tomato varieties, especially those that produce very large fruit, are particular susceptible to growth cracks.
Catfacing is a similar tomato disorder that causes fruits to develop puckered surfaces and distorted shapes. Bands of tan-colored scar tissue may also run across the blossom end of the fruit. The disorder occurs when weather conditions interfere with proper pollination and fruit development. Both cold weather (below 50°F) and hot weather (above 85°F) can cause catfacing and fruit cracking.Prevention and Control
- During pollination, protect your tomato plants from temperature extremes by covering them with shade netting.
- Keep soil uniformly moist throughout the growing season.