Ukraine’s Danube Shipping Company (DSC) has asked Romania’s Constanta Black Sea port to allow ship-to-ship grain transfers which would almost double its barge export capacity, the company said on Monday.A major grower and exporter, Ukraine’s 2023 grain output is seen at up to 56 million metric tons but a blockade of its major Black Sea ports since Russia’s invasion in February 2022 has constrained shipments.Ukraine’s Danube river ports, which previously accounted for around a quarter of grain exports, are now the main route out for the country’s harvest, some of which is sent on barges to Cons