Hello! So I've been playing guitar for about 8-ish months, and I keep running into a snag. Whenever I'm playing certain songs, there just seems to be too much sustain on open strings when certain chords are played. Is this a technique issue?
Tony Done 
My first post so excuse me if its not as technical as some . 

I'm an acoustic and electric player 5yrs or so. I have a Krafter Sat-Qmos. It has a lot of sustain. By this I mean a single string pluck will produce a note which lasts about 5-6secs. My practice amp is a Mackie SRM150 having no reverb controls etc.
As a rhythm guitarist it didn't seem a problem when playing in my group but when I came to record my guitar  recently it had an almost consistent buzz/hum in the band setting, clearly audible on playback. This was on an 8 track so I could compare it to the lead guitarist for example. 

Now I admit I had never thought that consistent palm muting was a required technique for electric players as opposed to Acoustic where it is used for short term percussive effect. The single pluck 'test' produces approx 3-4secs sustain on my ( expensive luthier built) acoustic  guitar

Having read the other posts, relating to this topic, it seems to be a general opinion that ' technique' is the primary source of sustain control. (Note, I did try the piece of foam suggestion but it killed it stone dead so that it was plinky-plonky. Also the elastic band referenced in another article. 

So, is the situation such that rhythm guitarists would  rest their palm heel on their strings the entire performance and execute strumming patterns and lift off when they wanted the chord to sustain, say at the end of a verse etc?