i was wondereing if i could start my plot with just a PTO driven tiller or do i need a plow?

Yes, many people use a tiller only. But, I wouldn't want to go much more than an acre or two.

It'll be a lot easier on the tractor to use a plow first, a tiller is doable though

Thats all I use.

thanks guys all im gonna do with it is about 1 -2 acres

I wish I could use a tiller, but its way to rocky where my plots are.

Most people use a disc or cultivator just for speed and less fuel usage. A tiller is actually better. The soil has a finer consistancy and is mixxed thoroughly. This makes a perfect seed bed. And promotes a better root system. If you have a little tractor you may want to rev it up pretty good and use 1st. If you have 40 or more hp you can probably get by with half throttle or a little less in second. Just keep in mind you want the engine revved up enough and puttlng along so you are churning the soil. This will dig the rocks up. If you lug the motor it is possible to break the crank in the worst case or pto in the best. You want the strain to be on the tiller tines instead of the engine if it hits a big boulder under ground. I have never broken a tine. But have seen 3 guys break their cranks on 20 hp or so gas tractors from lugging the engine at low rpm. Just don't get in a hurry and don't get cheap on the fuel usage. One more tip, you may considder tilling twice. Let's say your model goes 8" deep. Till 4" then wait 2 weeks for emergence then go 8". I have good results doing that without using roundup.
Blessings

mine is 20ish hp diesel

I use an old 24hp diesel kabota and a 5ft tiller and it workrd just fine. Just go slow.This tractor has a 3 speed pto and I put it in 1st for more power. I did about 1.5 acres tilled itand then ran a lime wagon this fall and used about 2gal gas. Then I will till it this spring just befor I plant. Illsee how it works.

I'm not a big fan of tillers. They are very hard on the soil, especially with prolonged use.