The decline in April output was mainly from teas grown in the low and medium elevations, with over a million-kilo shortfall in low grown teas which make up over half the crop, Tea Board statistics show.
Teas from the high grown estates, mainly produced by regional plantations corporations, actually increased in April 2011 compared with last year.
But the Tea Board said national tea output in the first four months of 2011 rose two percent to 106.3 million kilos from 104.2 million kilos the previous year.
Favourable weather, extension of government fertiliser subsidies to all crops and strong demand from overseas markets were likely to boost production this year, industry officials said.
Tea Board officials have said tea production could hit a new high in 2011, exceeding last year's production of 329.