Sri Lanka's tea production fell in September for a sixth straight month due to adverse weather in high growing areas, the island nation's state-run tea board said on Wednesday.

Tea production in September recorded 22.93 million kilogrammes (kg) against 25.61 million kg in the same month last year. The output in the first nine months has slipped 1.3 percent to 245.16 million kg from 248.27 million in the same period last year.

"The main reason is the climatic conditions. In the high-grown areas the plucking days are restricted to only two to three days per week," Sri Lanka Tea Board Director General H.D. Hemarathna told Reuters.

The tea board expects full-year output to end near last-year's record high of 329.4 million kg. The tea board hopes revenue from Sri Lanka's No. 1 agricultural export crop will rise to a record of more than $1.5 billion this year, from $1.4 billion last year despite turmoil in the Middle East and North Africa, home to some of the island nation's major customers.

Sri Lanka's earnings from tea exports have risen 3.7 percent to $832.3 million in the first seven months of 2011, the central bank's latest data shows. Earnings gained 16.1 percent to hit $1.4 billion last year.

Tea is one of the $50 billion economy's main foreign currency earners, along with remittances, garment exports and tourism. (Reuters)