Beginner Gardening: What is the problem with my tomatoes?, 2 by Kvanwoensel

Kvanwoensel wrote:
Hi there!

The lower leaves of my tomato plants are turning purple, start to curl and dry up. On the stems I see little black spots...Is this potassium or phospor deficiency? I use compost mixed with a small amount of horse manure and wood ashes, so I don't see how there could be a deficiency. My other plants (Melons, Peppers, Eggplants and Ocra's) don't have these problems and are growing really well... They are also given enough water.