A new documentary on the history and future of Delaware agriculture will air next weekend on WHYY-TV, in time to kick off the Delaware State Fair. “Delaware Agriculture: Farming the First State,” a 30-minute documentary, will be broadcast at 5:30 p.m. and 11 p.m. July 19, 11 a.m. July 21 and 5:30 p.m. July 22.