Fans of the chocolate spread Nutella or the hazelnut-filled Ferrero Rocher could soon be facing rising bills for their nutty treats because of poor weather in Turkey. Prices of hazelnuts have surged in recent weeks after cold, late winter weather and bitter frosts caused a poor harvest in the nut's chief exporter, Turkey. The rise has been so sharp that it risks driving up the prices of popular consumer products like chocolate spreads or nut-filled chocolate bars.Half of Turkey's exports go to Germany and Italy, the headquarters of the Italian giant Ferrero, which owns brands like Nutella and Kinder, and is the world's largest buyer of hazelnuts. Ferrero said in a widely reported statement that it was "tracking this issue closely, and there's no foreseeable impact on the availability of Nutella." It may seem strange that the price of Nutella could be the victim of a cold snap on Turkey's Black Sea coast, which is the hub of the country's hazelnut industry, but this is the bitter reality after four hazelnutproducing Turkish provinces on the Black Sea - Giresun, Trabzon, Rize and Ordu - in March were hit by storms and unusual freezing weather that destroyed part of the harvest.Production of hazelnuts in Turkey usually amounts to 590,000 tonnes a year - three-quarters of global consumption. But according to Turkish hazelnut growers, production this year is set to fall to 370,00 tonnes. The fall in supply has already led to a spike in wholesale prices, which have climbed some 80 percent. "Last year, the price of a kilo of hazelnuts was around six Turkish lira ($2.75). Now it has reached 11 lira ($5)," said Nejat Yurnur, head of a hazelnut factory in Ordu.