Ed,

The opener Tommy is using puts a band down and his 15" is different from what you would get using a standard drill with a single row of wheat every 15". The Horsch opener leaves the seed in about a 6" wide band so there is really only 9" or 10" open between bands. Not really accurate to call it a "15 inch drill". But it does a nice job on wheat where you can use it as you can see.

Jim at Dawn