SAO PAULO (Reuters) – Scarce rains in December will reduce soybean yields and possibly output in Brazil’s largest-producing state, farmers from various regions of Mato Grosso told Reuters on Wednesday.

Dry weather and high temperatures are also accelerating the soybean cycle, leading some growers to anticipate harvesting even at the risk of lowering yields.

“I had 10 days of drought on my property,” said Laércio Lenz, who grows soy in Sorriso, Brazil’s largest soybean town. In some parts of that large municipality, farmers have faced dry weather for around 20 days, he said.

Mato Grosso’s own soybean output is projected at 32 million tonnes this season, around 25 percent of Brazil’s total, according to government estimates.

Lenz said calculating the extent of the drought-related damage will only be possible as the harvest progresses. But based on historical data, farmers could lose one 60-kilo bag per hectare per day that they anticipate harvesting, he said.

Mato Grosso’s average yields were more than 56 bags per hectare in the last season, a record which is unlikely to be matched, Lenz said.

Data from Thomson Reuters’ Refinitiv indicate that rains were uneven and came at relatively low volumes for most of this month in Mato Grosso. The forecast through Jan. 10 is for rainfall to remain below average in the center-west of Brazil, the data showed.

Eastern Mato Grosso was hardest hit by dry weather, said Antonio Galvan, head of the state’s grain grower association Aprosoja-MT.

The situation indicates the season, which started out well, could bring losses for farmers and lead to downward revision of the country’s grain production forecasts after states including Paraná and Mato Grosso do Sul also reported lack of rainfall.

The government estimates national soybean output at 120 million tonnes. Before the drought reports, some analysts saw a potential of nearly 130 million tonnes.

Arlindo Cancian, from Canarana, in eastern Mato Grosso, confirmed that the region was badly damaged by the lack of rainfall.

“I have planted 900 hectares, with half of the crop receiving rain and half had no rain,” he said. He said that several producers are “in trouble” as temperatures have been very high.