david at alegba.demon.co.uk
Thu Mar 2 16:11:32 EST 2000
Can anyone help? If you can I would be most grateful.
I am seeking answers to three questions
1. To what extent did the yield per acre of N. American cereal production
increase following the introduction of selective herbicides in the 1950's?
2. What is the present contribution of N.American cereal production to world
3. Are world food reserves still about 405 of annual production and has this
changed appreciably over the last 50 years?
very many thanks
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