The interruption to supplies of fertiliser and its key ingredients due to the war in Iran could cost up to ten billion meals a week and will hit poorest countries hardest, according to the boss of one of the world's biggest fertiliser producers. Svein Tore Holsether, chief executive of Yara, told the BBC that hostilities in the Gulf, which have blocked shipping through the Strait of Hormuz, are jeopardising global food production. Reduced crop yields as a result of lower fertiliser use could