UT Extension

The University of Tennessee

AGCO  (Under "Products" select "tractors")

Buhler

Versatile

Challenger 

Fendt

John Deere (select "North America" and "brand")

Kubota  

Mahindra

Massey-Ferguson

McCormick

New Holland

Saukville

Tructor

Valtra

 Disclaimer
"Links to commercial sites are provided for information and convenience only. Inclusion of sites does not imply University of Tennessee approval of their product or service to the exclusion of others that may be similar, nor does it guarantee or warrant the standard of the products or service offered."