During the first half of the 20th century, the policy stance towards South African agriculture swung from suppression to support. More recently, the agricultural support policies were eliminated. Using newly constructed, long-run (1918-2015) data concerning maize production, yield and average price, we show these switching agricultural policy regimes had significant production, productivity, and climate risk implications for the maize sector. At its peak, this policy-induced movement reduced maize productivity by between 7.9 and 15.3 percent. The removal of the distortions coincided with a contraction in the total area planted to maize, but some spatial productivity perturbations still persist.