The growth of eight core sectors slowed to 3.6 per cent in the month of May due to fall in output of coal, fertiliser and steel. The growth rate of eight infrastructure sectors — coal, crude oil, natural gas, refinery products, fertilisers, steel, cement and electricity — was 5.2 per cent in May last year.Coal and fertiliser productions recorded negative growth of 3.3 per cent and 6.5 per cent, respectively, as per the government data released on Friday. Steel output dipped to 3.7 per cent last month as against 13.4 per cent in May 2016. In April, these eight sectors had recorded a growth rate of 2.8 per cent..