Tomatoes grown "Delicious" 38oz example. I also had luck with German pinks and Mortgage lifters, producing over 120 lbs of fruit from just 3 plants.
I have grown;
German Pinks are a potato leaf type and seemed to be more resistant to leaf rot this 2011 season. Though they take a bit longer to produce ripe fruit. Their flavor was wonderful, and produced the best looking fruit.
The Mortgage Lifters were slow to produce great tasting pink fruit they were the most sensitive to drought conditions. I had had very good luck with Mortgage Lifters before, this year they were not the bet producers. (Last grown 2009)
Delicious are giant great tasting tomatoes, but they have an odd shape and a big core, making it hard to slice. No pretty but they taste wonderful. Very short shelf life due (I believe) to their easy to damage skin. Use the quickly. (Last grown 2009)
Whoppers (and Parks whoppers) Very early with a great tomato flavor, with oddly (because of the name) they were average size that went on till frost. These kept well, and I had the last of my tomatoes I February 2011.
Best luck was with soil PH at about 5.7 to 6.2 as it controlled leaf rust as well as produced an acid soil the tomatoes (and not weeds) loved. When watering with tap water (from Indianapolis Indiana) it was very hard and base (after the chlorine evaporated which produced a temp positive unstable acid condition) so it was important to check often and use "good practices" when testing tomato beds. Many impatient gardeners try to rush the science approach without an understanding of the chemistry and physics involved. They get mixed results and default back to the "seat of the pants" approach.
In testing your soil use only distilled water read all the directions and take the time to wait for the complete reactions. Don't short cut here!
Besides soil ph I found adequate sunlight to be very important. I was able to improve the amount of exposure (restricted by my neighbor's trees) by using a "angled staking" approach to the beds to increase production. This has several added benefits, as it proved stronger and more convenient than staking plants at 90deg to the earth. The simple use of a sun dial (used at actual high noon) will tell you the best angle at your latitude. Example; Indianapolis is at 39deg N. so you can figure it from there, that a 40deg slant will increase sun exposure to your tomatoes. Can you over expose tomatoes? I don't think so with conditioning. A sudden change will burn them, but grown this way is no problem. It adds a great deal of strength to the vines to help prevent stalk breakage with heavy bearing varieties.
Water - Always! I do :15 per day or about an inch per week from bottom to avoid dirt splash, and fungus.
Fertilizer - Overused, often and a very confusing subject. Nitrogen is important to all plants but it is not enough by it's self and can turn the soil base (ammonia). "Organic growers" won't use "chemicals" but often miss trace element nutriments like copper, and others. These "organic growers" should remember that everything is a chemical and get over it, as it does not matter the source it it the composition that matters. I use a mix of methods, and use as little as I can get away with, starting with a good composed mix an adding a tomato fertilizer as the season progresses always doing the PH test afterwards.
Organic growers have to be wary of accidentally creating the "Petri dish effect" and invite viruses, bacteria, and molds to grow, so be careful of your sources. Use your own compose and you should not have a problem, you didn't have before...
Don Mindach - Spring 2011