This certainly is a more effective use of land than simple solar farms. Mold and scab can be mediated by protecting fruit and nut trees from splashing during rain events and keeping the leaves dry. You should check out some of the research of French agricultural scientist Dr. Christian Dupraz on "agrivoltaics". You can find a summary of the project at: http://www.carbonranching.org/SOLUTIONS/11_AgrivoltaicSystem.pdf . According to that article, "the crops under the half-density shading were not only as productive as the control plots; in a few cases they were even more productive!" So energy and food really can be farmed on the same plot of land.