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SCALE .7

Distribution of 209 World Wheat Areas According to Annual and Pre-Harvest Precipitation and Tennperature.

I. The most strikinR feature of this chart is the concentration of "high" and "superior" yields of wheat within the middle ranges of annual and pre-harvest precipitation and of annual temperature.

1. Of the 60 areas characterized by an annual precipitation of less than 20 inches, only 18 had long-time average yields of wheat above 14 bushels. These 18 are dryfarming areas in Canada and the western United States.

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