A survey by the Minnesota School Nutrition Association and the Institute for Agriculture and Trade Policy has found that the number of Minnesota school districts buying fresh food from local farms is growing. The groups surveyed nearly 100 public school districts across the state, with 69 reporting that they bought Minnesota-grown products in 2009. That was more than double the figure from 2008. Apples, potatoes, peppers and sweet corn were among the most commonly purchased products.