I don't believe there is much use in concerning yourself with the "trunk". Banana are not trees, they are perennial herbs and what we see as a the 'trunk', is actually a a pseudostem,a single stem rising from the rhizome ( or corm) and it is tightly wrapped with leaves. Once it is cut, the growth will likely stop and your best bet is to save the rhizome and start again from the root stock come warm weather.
Truth is not what you want it to be; it is what it is. And you must bend to its power or live a lie.”― Miyamoto Musashi
"Knowledge speaks, but wisdom listens." ~ Jimi Hendrix
“The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.”― Stephen Hawking
Craig