Disappointed with the factory output growth of 4.1 per cent in August, Finance Minister Pranab Mukherjee today said it may impact India's second quarter GDP. The factory output, as measured by the Index of Industrial production (IIP), was 4.1 per cent in August, lower than 4.5 per cent in the same month last year.Mr. Mukherjee, however, declined to comment on the extent to which the subdued IIP numbers will impact the economic growth during the July-September quarter or Q2 of this fiscal. India's economic growth fell to 18-month low at 7.7 per cent in the April-June period or Q1. The government expects the country to grow by around 8.5 per cent during 2011-12. As per the official data released today, the IIP growth during the April-August is 5.6 per cent, as against 8.7 percent in the corresponding period of 2010-11.However, July IIP growth has been revised upwards from 3.3 per cent to 3.8 per cent.