Potential Catface Problems in Tomatoes

Jerry Brust, IPM Vegetable Specialist, University of Maryland

It is possible that in about 4-5 weeks from now several sets of tomato fruit will start to show up with catface or that are deformed. Catface results in tomato fruit with deep indentations in the blossom end or fruit with significant distortions (Fig. 1). Chilly temperatures during flowering have been shown to increase incidence of catface. Temperatures of 54F or lower at the time of blossom set distorts and kills specific cells that should have developed into fruit, resulting in the deformities. While the disorder is most often observed in first-formed fruit, it can occur in any age fruit. We have had many cool nights the past few weeks with lows at or below 54o F for several hours. These night temperatures are some 8-10F below what the average low should be for late May and early June for much of Maryland. Tomatoes in high tunnels should not have any problem with catface as night temperatures would not have dropped below 55o F. Some tomato varieties will be more sensitive to these lower temperatures than others. It seems the ‘rounder and larger’ the fruit the greater the chance of catface. So, in the same field that has several cultivars of round tomatoes that have catface, plum tomatoes would have fewer problems and the cherries and grapes much less if any.

Other less common causes of catface could be extreme fluctuations in night versus day temperatures, tomato plants exposed to 2, 4-D but you should see a pattern in the field if this is the case with the area of the field possibly exposed to the herbicide with more damage than other areas of the field. Heavy pruning in indeterminate varieties may increase catface because of reductions in auxins in the plant. Jointless tomato varieties seem to be more prone to catface than jointed varieties. There is some research that shows catface can also be caused by thrips damaging the side of the pistil of tomato flowers.

Unfortunately, there is little that can be done to control this problem, except selecting varieties that are not prone to catface or growing plants in a high tunnel. Older cultivars appear to be more susceptible. If possible, removal of the catfaced fruit would be beneficial as these fruit are unmarketable and will continue to drain nutrients from the plant.

catface deformity on tomato fruit

Figure 1. Catface on tomato fruit