Kubota's are assembled in Georgia, but the engine and transmission are manufactures in Japan. There are probably many critical little widgets that come from Japan that could affect production. The John Deere 2000 Series are manufactured by Yanmar and are also at risk for manufacturing delays.
We depend on a very complex global supply chain for all of our daily purchases with many subtle dependancies. Several years ago in Japan there was a fire at a piston ring manufacturing plant that ended up halting production at something like half of the Japanese auto plant for almost a week. This was one small fire, but no piston rings, no engines; no engines, no cars.
This goes far beyond tractors, think about digital cameras, flat screen TVs, Japanese cars, computer memory. Even domestic cars are at risk, I can guarantee somewhere in your domestic car is a computer chip that is spec'ed from Japan. If you have everything to build a car except a $2 chip, guest what, it probably isn't going to happen.