I am posting this here as much for myself as for all of you, but I want to provide you with a quick link to the USDA’s National Agricultural Statistics Service Quick Stats page. It allows you to find data on yields and other ag data for many different crops as a variety of spatial scales. The length of the record depends on the crop, but I checked and peanut data goes back to 1909, while pecans only go back to 1990. I hope to be using some of this data to go back and look at trends between crop yields and climate conditions in the coming months. You can find the page at https://quickstats.nass.usda.gov/.