as long as he has some leaf stems attached to the main stem, the plant will start new growth from the joints. the result of the mishap is your uncle will have bushier plants.
the plants may be set back a bit from producing tomatoes, but ultimately, they should be ok.
if some plants have just main stem with no joints where a leaf was attached to the plant, i would think those plants would not be able to generate new growth, and would remain just stem.
does that make sense?
if the parts that broke off are big enough, uncle could try rooting them.
keith
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