Misshapen tomatoes with cracks
"Catfacing" of tomatoes is a perennial problem for home gardeners. Fruits are misshapen (often with deep crevices or holes) and scarred on the blossom end. This disorder appears most frequently on the early fruit clusters of large-fruited cultivars. The cause is exposure to cool temperatures- below 50° F.- after transplanting.
Don't set out transplants until temperatures warm sufficiently (1-2 weeks after the last expected spring frost.) One must increase soil temperature and ambient temperature to successfully grow early tomatoes that are not badly catfaced. Remove all catfaced fruit immediately because they will not ripen uniformly and will divert plant resources away from developing fruits.