UPDATE 1-Rain slows Brazil sugar output by 23 pct in late Sept.
SAO PAULO Oct 10 (Reuters) - Sugar output from mills in Brazil's center-south plunged 23 percent in the last two weeks of September from the first two weeks of the month after rains kept mechanized harvesters from fields, local industry association Unica said on Thursday.
Widespread rains in recent weeks over the main center-south cane growing region have slowed mills' crushing as the season enters its final leg. The region generated 2.29 million tonnes of sugar in the last half of September, down from 2.96 million tonnes during the first half of last month, Unica said.
Cumulative sugar output since the season began on April 1 is still up 5 percent from a year earlier at 25.2 million tonnes.
But mills, which have harvested 440 million tonnes of the record 587 million tonne 2013/14 crop, began to favor ethanol production more in late September compared with earlier weeks, Unica data showed.
"The machines that harvest couldn't manage to enter the fields with the soil so wet, which hurt the rhythm of crushing," Unica's technical director, Antonio de Padua Rodrigues, said.
Sucrose, or the type of sugar that crystallizes, in cane plants tends to fall in the weeks following rainy periods, which makes sugar production more difficult. Mills tend to favor ethanol production, which does not require sucrose, when weather is wet or sucrose levels are low.
Mills on average in the region allocated just 46.85 percent of their harvested cane to sugar production in the last fortnight of September versus 49.14 percent in the first half of last month, Unica data showed. Meanwhile, ethanol production has gotten a greater share of the cane crush. (Reporting by Reese Ewing; Editing by Gerald E. McCormick and Kenneth Barry)