Vol. 51—1997 - NorthEastern Weed Science Society

Waggoner December 24, 1994
133
In fact, desp te lifted averages, master farmers stay ahead,
Fig 3. The bo tom line shows world farmers lifting their
average yield of corn, the middle shows Iowans lifting their
average, and he top shows Iowa Masters lifting their winning
yields. The g p between and opportunity for higher yields
continues.
20
15
Iowa Master
Iowa average
5
o
1960
World average
965 1970 1975 1980 1985 1990 1995
Fig 3. The co
Iowa and the
Grower's Cont
USDA and FAO
rse of average maize yields in the world and
ourse of winning yields in the Iowa Master Corn
st. (Personal communication by W. R. Hansen and
tatistics, various ears.)
Searching for a ceiling for yields I found the 1992 winner of
the national orn contest grew 21 t/ha in Pasco, Fig 4.
Farmers can l'ft the U.S. average corn yields without
striking the eiling.