Pumpkinlover, there are real weather differences between mainland USA and UK. Our higher latitude degrees cause two main differences, sun angle and sun intensity. It is so much sunnier further south, this means that foliage grows smaller, plants are shorter because they are not stretching towards light as much as in the UK. In the USA the problem is 'sunscald' as they call it, ie tomatoes being burnt at the shoulders by too much sun. In the UK the universal problem is too little sun to ripen all of the tomatoes and far too much shading by leaves. Far from being 'nonbeneficial', for us side-shooting and pruning are really helpful, essential even.
Most of USA has continental climate and that means far less cloud cover than in the UK. Guess what all this cloud does to sunlight getting to tomatoes? And the answer is still the same - limiting foliage. Not growing in 'tomato cages' which push foliage together, but side-shooting and pruning and limiting to a few trusses only.
As Jeannine says (who does have experience growing in more than one country) - we do know a thing or two about gardening in the UK and we definitely know how to grow tomatoes in our climate. In fact, because we are near the geographic margins of tomato growing, we had to get quite clever to achieve good yields. We can never hope to get the yields achievable in the med or in many states of the USA, but we are doing it, year after year, our way.
Some people here may have read about the woes of USA tomato growers in 2010 when late blight caused wide-spread crop wipe-out in many states of the USA, due to unusual weather conditions. Growing in tomato cages, which limits air circulation contributed to the speed and devastation this wave of blight caused. Every method has its pros and cons. In this instance it was positively nonbeneficial to US gardeners.
There is no 'one-size-fits-all' method in gardening. It is just not that simple.
