I can't figure out what is going on with the inner and lower leaves of my tomato plants. Please see pictures. They start out like the first pic end up like the 2nd. The whole stem dies right at the junction.
Any help would be appreciated.
It looks to me like blight. It's a fungus.
Cut these leaf branches with scissors and put them in your compost pile.
If you see it starting on other leaves, mix one teaspoon of baking soda with a quart of water and in the evening, spray the plant, top to bottom - avoiding the growbed. You may want to place some paper towels around the base until you are done spraying.
Either looks like you're dealing with some kind of pest or powdery mildew....Take a really close look at the leaves with magnifying glass or microscope. You could have spider mites or thrips.
Try NEEM oil, diluted, 1 tblsp NEEM to 1 gallon of water. it is a natural leaf polish, as well as great for treating powdery mildew, mites, and many other pests. Can be sprayed on plants up to the day of harvest!