Where are my Orange Russians?

[microcollie]

I'm growing a few types of tomatoes this year...jaune flame, juliette, and japanese black trifle are all doing well. I have two orange russian plants sharing a trellis with my 2 black trifles, which aren't fruiting. The plants look very healthy and are blooming profusely, but the flowers just fade away without producing fruits. My 6' tall plants have only 2 tomatoes each . The black trifles are straining under the weight of their fruits. The fact that the others are doing well makes me think that the problem isn't caused by lack of pollenators. Any clues?

[TZ -OH6]

Some varieties are more susceptible to heat and nitrogen levels than others. If everything was acting poorly the situation would be more clear cut, but as is it might just be bad luck for those plants, wrong place at the wrong time. That is one reason I never put two plants of the same variety close together.

[microcollie]

Oops! Sort of late to do anything about that now. But it's on my list for next year. Thanks.