In December, the forecast had been 240,675 metric tonnes, after taking into account 8,000 metric tonnes of damages from the fall armyworm infestation.
However, following a January assessment, the forecast had been lowered to 200,000 metric tonnes, an official said.
In the 2017/18 Maha season, the maize harvest was 274,399 metric tonnes.
Of the 70,700 hectares of maize sown in the current 2018/2019 Maha season, 40,000 hectares have been infested by the insect to varying degrees.
Farmers had managed to control the infestation to some degree with pesticides and other methods.
Some of the crop now classified as damaged could therefore be recovered, and the final harvest could be higher than forecasted, the official said. (Colombo/Feb01/2019 - SB)