Lots of questions on here about tractor requirements for disc mowers, I'll share my experience.
Disc mowers require a tractor with 3ph hitch, catagoriy 2 AFIK, and remote hydraulics.
At the present I have a Vermeer 9 ft. mower. Book says a 70 hp tractor is needed, 60hp for a 7 ft. 11 inch mower. I previously owned a couple of Vicon 7 ft. 11 in. mowers. I used a 64 hp tractor which played with them. I presently use a 65 hp tractor with the 9 ft. and the only time it has shown that it is loaded is when cutting very thick Fescue with the dew still on it.
Hp is not the only issue with a disc mower. The tractor must be heavy enough to handle it. The 64 hp tractor, a Long, is not very heavy but the only noticeable problem was that when turning sharply to the left the front wheels would not have enough traction to turn and the tractor would try to push straight ahead. It would do this if the mower was picked up as well as being down in cutting position. Turning to the right was no problem. Useing the left turning brake helped. Therefore, if your tractor is light you need to add weight to the front.
Another weight issue is turning sharpely with the cutterbar all the way up. You have the heavy bar up in the air and the 3ph raised. Turning sharply could make a light tractor tip over.
When looking at 9 ft mowers a NH dealer stressed that the NH 3ph mowers were heavy and a heavy tractor was required. That's not why I got the Vermeer, but it weighs 1291 pounds which is lighter than the NH, don't know how much. The tractor I have, a Zetor, is heavy at about 6600 pounds. It also has loaded tires and a heavy Great Bend loader with a lot of 1/2 inch steel plate in the framework made for that tractor. There is no problem with turning the disc mower.
For common tractors with or without a loader, I consider the 5000 Ford to be ideal for handling a 9 foot disc mower. I've never owned one, yet, but IMO one with those general specifications should do fine.
A final note: I've moved the Long tractor with 7 ft 11 in mower on a trailer, and I wouldn't feel comfortable driving on forward for fear the front end would be too light.
KEH
