Brazilian sugar mills in the country's center-south region crushed 16.3% more sugar cane in the first half of June than in the same period a year earlier, sugar-industry group Unica said Wednesday.

Mills in the region, which last year accounted for almost 90% of Brazil's cane harvest, crushed 41.5 million tons in the two-week period as dry weather helped speed the harvest. That compares with 35.7 million tons a year earlier.

The mills produced 2.3 million tons of sugar in the two-week period, a jump of 29.7% from a year earlier. Ethanol output rose 14% from a year earlier to 1.7 billion liters.

That left a sugar/ethanol production mix of 45.4%/54.6% for the first half of the month, compared with 42.3%/57.7% for the same period in 2013.

The worst drought in decades in several states of the center-south region has helped accelerate the harvest by keeping fields dry and making it easier for equipment to operate, but has reduced the productivity of the fields.

The dry weather has "severely harmed the development of the plants," according to Unica's technical director, Antonio de Padua Rodrigues. "The decline in the harvest observed until now is worrisome and should become more evident at the end of the harvest."

Through the end of May, cane fields were yielding 78.4 tons of the crop a hectare, a decline of 7.3% from the same period a year earlier, Unica said, citing a survey carried out by the Cane Technology Center.

In the harvest season through June 16, mills in the center-south region crushed a total of 158.9 million tons of cane, an increase of 3.7% from the year-earlier period, Unica said.

Sugar production in the period rose 4.4% to 7.8 million tons, and ethanol output increased 2.8% to 6.6 billion liters.

The production mix for the season through June 16 was 42.2% sugar and 57.8% ethanol, compared with 41.8% sugar to 58.2% ethanol a year earlier.