Sri Lanka's tea output fell for the eighth month running in September, data from the state-run Tea Board showed on Friday.

Brokers said the decline was due to a series of factors including drought following flooding, the poor application of fertiliser, low market prices and a government ban on the use of pesticides.

Output in September fell by 27.2 percent from a year earlier, the Tea Board's data showed. The last monthly gain was in January.

"Now the drought conditions after the floods have hit the production," said Anil Cooke, head of Asia Siyaka Commodities, told Reuters.

Tea is Sri Lanka's top agricultural export commodity and one of the main foreign currency earners for the $82 billion economy.