Could be a combination of several things. There is clear evidence of nutrient deficiency as well as leaf edge death from either insufficient watering or being rootbound. All depends on if it is in a container or the ground.

You never want to leave such severely damaged leaves on a plant as it only causes additional stress for it so one always removes such damaged leaves from the plant as they develop. Suggest you start by doing that.

Has it been sprayed with anything? has it been treated with a fungicide? does it shows signs of any pests? What things have you tried to date to save it? if it had issues with BER early on then there has clearly been some long standing soil moisture problems.

Dave

What is root bound? Does it mean exposed roots at the surface? If so, I did notice that slightly on this plant, I suspect rain may have caused slightly erosion and I added some soil on top of that exposed part.

I checked the soil a couple days ago and didn't detect much dampness about 2 inches deep so i watered the base is this plant. I haven't tried anything else to date.

i have been adding some liquid fertilizer prior to noticing this problem for about a month, possibly I was too late to add such nutrients. But this is a new raised bed and I suspected the soil mixture would have offered enough nutrients for the first few months.

This is plant also had a bunch of aphids on many leaves early in the season Two applications of neem oil helped greatly, but the tomato plant is now so large I have a hard time viewing the leaves near the base where there was originally a problem

thanks for your help and advice. I will remove the damaged leaves and hope I'm not too late

If it matters, Dave, this post I made earlier contains some pictures of this same plant. I thought at the time it may have been due to moisture/humidity. But offering it as information to you if it helps paint a better picture of the current problem

http://forums.gardenweb.com/discussions/4087807/what-is-on-my-tomato-stems

Root bound means the plants roots are over-crowded in, contained too tightly, in a container. You hadn't indicated if this plant was in ground or in a container.

Since it is in a raised bed and given the history of its many problems - stem splitting, adventitious root development, BER, foliage margin death, superficial root development at soil level, etc. then best guess of its primary problem is inconsistent soil moisture levels - extremes ranging from excessively wet to far to dry and then back again to overly wet.

All of those problems are caused by radically inconsistent soil moisture levels. Whether that is caused by weather, your watering practices, your soil's water retention/drainage issues or a combination of all of them I can't say. But you need to figure out how to stabilize it so that the plant's roots have a stable, consistent level of moisture available to them rather than them having to fight the two extremes all the time.

You may need to make soil improvements so it drains better after heavy rains, you may need to make soil changes so that it retains water longer, you may need to radically change your method and frequency of providing water in both frequency and amounts, you may need to mulch and mulch heavily, etc. I can't say. But it requires monitoring of the soil moisture level several times a day until you can get a handle on it.

If you water the plants and 12 hours later the soil 4-5" deep is dry then either they didn't get enough or the soil has retention problems. If you water and 2 days later the soil at 4-6" deep is still too wet then either you give them too much or the soil drains poorly. If it rains use a rain gauge and then check the soil 4-6" down to see how wet it is. In most cases rain alone does not provide enough water to plant roots because it is distributed or a wide shallow area. These are just a few of the investigations you need to do.

But if stems spit it is due to extremes of water, if adventitious roots develop in large numbers it is due to too much water, if soil-level shallow roots develop it is usually due to too frequent shallow watering, etc.

Dave