0187-5779 0187-5779 S0187-57792018000400337 10.28940/terra.v36i4.335 Mexico 00 12 2018 00 12 2018 36 4 337 343

2006 20 20 3159-78 2003 2013 6 6 474-82 1962 54 54 464-5 2011 84 84 1-21 2012 15 15 148-61 2012 452 452 130-8 2016 321-46 2006 1993 7 7 203-17 2001 315-25 1997 11 11 113-26 1999 41 41 11-25 2000 40 40 323-36 2006 24 24 39-49 2010 3 3 279-84 2011 75 75 1282-91 2009 27 27 237-46 1996 59 59 35-58 2009 27 27 287-93 2006 67 67 208-25 2009 73 73 1023-8 2013 16 16 529‑546 USDA (United States Department of Agriculture) 1999 1947 63 63 251-64 1997 61 61 1024-30