The new boss has now managed just one point from his five League One matches in charge and is still looking for his first win after the Tractor Boys got back to winning ways.
The goals came via a brace from Conor Chaplin, a volley by Nathan Broadhead and a header from Freddie Ladapo.
The defeat plunges the visitors deeper into the relegation mire with their 12th winless match on the trot and now nine points from safety.
Chaplin found the back of the net after three minutes while Rovers goalkeeper Ross Doohan was kept busy.
He palmed a shot from Leif Davis round the post, denied Broadhead and Wes Burns and George Hirst lobbed the goalkeeper but his effort hit the top of the bar.
Broadhead put the home side further ahead in the 41st minute and Hirst’s deft touch was cleared off the line by Oliver Casey.
Chaplin scored a third for Ipswich in the 60th minute following a cross from Davis and Doohan tipped a shot from Kayden Jackson over the bar.
The fourth goal came from Ladapo in the 79th minute and Town failed to make it 5-0 when Davis’ shot took a deflection and struck the post.
Relegation continues to look more and more likely for Rovers, who have only 13 games left to survive an immediate return back to League Two.
Rovers’ head coach Ferguson said his side failed to “come out of the traps” quickly enough and that the best team won on the day.
He said: “We didn’t come out of the traps quick enough and got punished in the first three or four minutes and didn’t quite recover, then we concede again from a set-play just before the break and that kills you a bit.
“There’s no excuses to be fair, the best team won.
“You’ve got to learn and think about what you can do better. They are better than us and they were better than us today, it’s one of them and you’ve just got to move on and we’ve got another game next Saturday.
“When you’re conceding four goals, they hit the post and had a free header late on, it could have been a ‘right’ score.
“The boys had a go and that’s all I can say. We were aggressive with our line-up to start with but you have still got to defend set-plays.”