I agree that the probable problem is Blossom End Rot. A control method follows. >>Blossom end rot is usually evident early in the season and is most prevalent on the paste types or elongated fruited varieties. It is caused by a lack of calcium at the blossom end of the fruit and this may be exacerbated by uneven watering. I would suggest you water more often and keep as even a moisture level as possible. Check your PH to be sure the calcium is not "tied up". If the PH is acidic. add lime in the suggested quantity and this should take care of your calcium deficiency. If the PH is already OK, add agricultural gypsum to provide calcium. There are sprays on the market but I have found them less than stellar in their results. Be aware that blossom end rot usually diminishes as the season progresses.<<