I have four types of toms started from seeds, all were healthy from start, treated same way, planted in the same area in raised bed, same nutrients, water, sun and other conditions. I have 4-5 plants of each type: San Marzano, Golden Girl (yellow, shaped like roma toms), sweet million (red cherry toms), and red slicing type. All four have fruits, some are starting to rippen. Only San Marzano is rotting - every time I see a red tomato, I reach to get it only to find it has end rot. Why?