Gardeners!

First year with my own raised garden box. I have about 8 tomato plants in one box ( got a little over zealous ). It's a bit crowded but the plants are about 2 1/2 - 3 feet tall and most have budding green tomatoes.

I'm getting a bit concerned because one of the tomato plants has quite a few yellow leaves on the bottom. A couple other plants have yellow leaves but not as widely spread as the aforementioned plant. I'm including links to pictures of these leaves.

I water the plants in the early morning every other day or so. I always water at the base, never onto the leaves. I try to wait till the soil starts to dry out a bit before watering again. This makes me wonder if I'm possibly under watering.

Outside of that I'm concerned it could be a nitrogen deficiency or fusarium. I've read around on common funguses/diseases but can't find any smptoms that perfectly match mine. Any ideas from the photos?

Generally I have yellowing leaves with blackened edges and some scattered black dots. Also I should mention the one plant with the majority of the yellow leaves is the slowest to blossom.

Your help is greatly appreciated!

http://i.imgur.com/v0p2c.jpg

http://i.imgur.com/04TKx.jpg

http://i.imgur.com/ETCBq.jpg

http://i.imgur.com/LHNSV.jpg

http://i.imgur.com/zAsI1.jpg

http://i.imgur.com/Omdlb.jpg

http://i.imgur.com/2AiWS.jpg