If we look at the history of these two sets of data before the modern era of floating currency exchange rates, we can better see how they were correlated. This chart shows raw wheat prices, un-adjusted for the value of the dollar. The sunspot number data is shifted forward by 2 years to reveal that bottoms and tops in the sunspot number tend to be followed a couple of years later by bottoms and tops in wheat prices. This relationship got into some trouble in the middle part of the chart, when President Roosevelt's New Deal price fixing artificially inflated wheat prices. The intention in the 1930s was to benefit farmers by keeping wheat prices up. That effort switched during WWII to the government putting a cap on all prices, including wheat, to support the war effort. Rationing of food, fuel, and other items took over for market forces. Additional trouble came in the 1970s, when the Arab Oil Embargo pushed up oil prices in 1973-74, reducing acreage under cultivation. Then later in that decade, the rising value in the dollar pushed down the dollar price of most commodities compared to prices in other currencies. So using dollars to see the normal cyclical relationship in price data became problematic.
All of this explanation brings us (finally!) back to the lead chart above. In [the above] chart, I have adjusted the dollar price of wheat, multiplying it by the US Dollar Index, which was created back in 1971. This mathematical step produces a unit-less measure of the value of wheat by factoring out the dollar's movements. Doing this allows us to better see how the peaks and troughs in wheat prices have been related to the sunspot cycle. I want to emphasize again that the sunspot number is shifted forward in that chart by 2 years, to reveal its leading indication for how wheat prices will behave. The conclusion from this is that the upward move in the value of wheat right now is just following the swoop upward in the sunspot number that began in 2009. We should expect to see generally rising prices for wheat and other grains until about 2 years after the sunspot cycle has peaked, a peak which has not even happened yet.