Caused by too much nitrogen, acid soil, uneven watering or high humidity. These conditions inhibit the plants intake of calcium. Correcting these has always worked for me, but if you still have blossom end rot, one of the liquid calcium products available at garden stores should do the trick. Caused by injury to the plant during blossoming, often from a period of cold weather. Uneven watering, or a period of insufficient water or moist, cool weather.
Leaves become mottled with yellow and green mosaic patterns.
Over winters in the soil. With most of the wilt diseases, about the only options are to rotate planting locations every year. Attempt to sterilize the planting area with solar heat using clear plastic, grow varieties resistant to the type of wilt you have, or just live with it.