1. wheat 8-15% protein
   staple for 1/3 world pop
   1991 producers: China 17%, USSR 15%, India 10%, USA 10%
2. rice 7-8% protein
   1/2 world population subsists on
   brown rice- more nutrients
   1991 producers: China 36%, India 21 %, Indonesia 9%, Thailand 4%
   (USA 1%, but big exporter)
3. maize 10% protein
   N. America to livestock (70% of total produced)
   S. and C. America staple for humans 1991 producers: USA 40%, China 19%, Brazil 5%, Mexico 3%
4. potato 6% protein
   HIGH calories per acre. low value, little trade
   Produced and Used in Europe, N. America
5. barley LDC- for humans. MDC- for livestock
6. sweet potato tropical root crop
7. cassava (manioc) 1 % protein C. and S. Africa
8. Sorghum/ millet subsistence crop in Asia and Africa
9. Oats/rye Flour, or to Livestock, Europe
10. Legurnes good protein source
    LDC: humans. MDC: to livestock, nitrogen fixing in rotation