Farmers have been calling for higher prices for weeks, amid soaring diesel and fertiliser costs and limited supplyGet our breaking news email, free app or daily news podcastColes has increased home-brand milk prices by up to 20c a litre, with Woolworths set to follow as war in the Middle East starts to hit Australian grocery costs.The price rise will support the company’s bottom line against pressure from higher fuel and operating costs, while some of the revenue will be temporarily passed on to