This inscription is from the time of the so-called developed socialism and advertises a state monopoly enterprise. There was a fruit and vegetable shop in the building below. 

 In socialist Bulgaria, agriculture represented a major share of Bulgarian exports. For this reason, it was the focus of state propaganda. Production and export of fruits, vegetables, canned food, flowers, etc. were under a strict state monopoly. It was regulated in 1947 with the establishment of the company BulgarPlod Export. There were similar advertising signs in many of the shops in Plovdiv