green manure [mustard

I'm pleased yo say after my topic regarding sowing green manure [mustard] on August 14 its growing well on the plot but  as i understand from growing mustard before you turn it in before it flowers however looking at a gardening program the other day it said chop it up before turning in or digging in so i though just ask the question is it best to dig it in as it stands or should I chop it up with the rotavator then turn it in ?

the Mustard we grew last year bobbyt  i scythed it down before ploughing it in so thought if I used the rotavator it would chop it up more finer and therefore bury it in the ground better