UPDATE 1-Brazil's 2015 coffee crop down as robusta output falls -FCStone INTL.O - RTRS

NEW YORK, March 25 (Reuters) - Coffee production in the world's biggest grower Brazil could fall to 44 million to 45.5 million 60-kg bags in 2015, in part due to the drop in robusta output in the state of Espirito Santo, said INTL FCStone INTL.O in a report on Wednesday.

This is down from FCStone's 2014 estimate of 48 million to 49 million bags, and below most estimates gathered so far by other trade houses that range from 45.3 million bags to 49.75 million bags for the upcoming 2015/16 crop.

INTL FCStone estimated the country will harvest 32.5 million to 33.5 million bags of arabica and 11.5 million to 12 million bags of conilon, a type of robusta coffee.

"We believe that the larger-than-expected decline in conilon production in Espirito Santo contributes to the smaller total harvest this year. At the same time, the South of Minas Gerais, contrastingly, will see a slight increase in production," FCStone wrote.

The estimate is the result of staff crop tours accompanied by professional agronomists in early March through the states of Espirito Santo, Minas Gerais and Sao Paulo.

"We believe that unlike the previous year, this year, due to the high instance of irregular crop development, the crop forecast was much more laborious and difficult to ascertain," FCStone wrote.

"Certainly, there will be a need for further analysis of field assessments in the weeks to come in order to provide better quantification of the expected volumes to be produced."