The growth rate of eight infrastructure sectors in the country slowed down to 2.2 per cent in April because of poor performance of crude oil, natural gas, petroleum refinery products and fertilisers.The eight core sectors that also include coal, electricity, cementand finished steel, and have a eightage of 37.9 per cent in the Indexof Industrial Production (IIP), had grown by 4.2 per cent in April 2011. According to the data released by the commerce and industry ministry today, the cumulative growth rate ofinfrastructure industries during 2011-12 also slowed down to 4.4 percent, from 6.6 per cent in 2010-11.Natural gas and crude oil production contracted by 11.3 per cent and 1.3 per cent during April. Petroleum refinery products and fertiliser production shrunk 2.8 per cent and 9.3 per cent during the month.Coal, Steel and cement output grew by 3.8 per cent, 5.8 per cent and 8.6 per cent in April 2012. In the same monthlast year, coal output had grown 2.7 per cent, steel – 2.9 percent and cement – 0.1 per cent.However, electricity generation slowed down by 4.6 per cent, from 6.4 per cent in April 2011.