"At the present time the strikers are not consistent in that way to maybe score in every other or every game," Edwards told BBC Radio Suffolk.
"They're not going on a positive run, they will chip in with the odd goal but I think they need to put their heads down, dig deep and give a bit more."
He continued: "It helps so much when the strikers put away their chances, once they score it gives a release to the defenders because it makes our jobs easier."
Since putting six past Doncaster two weeks ago Ipswich have played three times and scored only once.
None of Paul Jewell's players have reached double figures this term, with Jason Scotland, who started alongside Connor Wickham at the weekend, their Championship top scorer with nine goals.
"I'll say, and I think the manager will continue to say it, we need to be a bit more hardcore, more lethal," said 32-year-old Edwards.
"We need to punish teams. Saturday was a typical example where we should have killed the game off in the first half. But unfortunately we didn't capitalise and find the goal."
Source: BBC Sport
Source: BBC Sport