Farmers in Romania and Bulgaria staged protests Friday to express their anger over the European Union’s response to a glut of agricultural products from Ukraine that they say are flooding local markets and undercutting prices. Last year, the EU waived customs duties and import quotas on Ukrainian agricultural products as a way of facilitating transport to third-country markets. However, farmers in Romania, Bulgaria, Poland, and other EU countries have been disproportionately hard-hit by an influx of cheap Ukrainian produce — namely grain — which stays on local markets and undercuts prices. Polish farmers have also held protests in recent weeks....