If your tomatoes aren't maturing like you want them to, it might be because of poor environmental conditions. A number of problems can result from poor environmental conditions, including blossom drop, blossom-end rot, cracks in the fruit, sun scalded fruit, catfacing and zippers on fruit.
Blossom drop is caused by excessively high or low night temperatures. Most tomato varieties won't set fruit unless temperatures are between 55 and 75 degrees F for at least part of the night. Sprays that supposedly prevent blossom drop may help somewhat if low temperatures are the cause but spray fruits often are misshapen and seedless. This is seldom a problem in Kentucky since summer night temperatures rarely drop below 55 degrees.
Blossom-end rot develops when environmental conditions prevent the proper distribution of calcium in the plant. The result is a leathery spot on the blossom end of the fruit. We get a lot of calls each year about this problem which most people describe as tomatoes rotting on the vine especially on the bottom of the fruit. Under stressful conditions, low soil moisture in addition to hot, dry winds, calcium moves into the leaves and bypasses the fruit, causing the leathery spot at the fruit's end. Wet conditions followed by a period of hot dry days also makes this problem worse.