Argentina could harvest fewer than 50 million tonnes of soybeans in the 2017-18 crop year, the lead analyst at the Rosario grains exchange told Reuters on Wednesday, as a prolonged drought looks set to continue harming yields. No significant rains are expected in the next 10-12 days, threatening a crop already reeling from hot, dry weather in recent weeks, said Emilce Terre, the exchange's head of research. That will likely prompt a reduction to the exchange's current harvest estimate of 52 million tonnes, she said.

"50 million tonnes is looking more and more like a ceiling," Terre said. "We had been talking about 52 million tonnes, and we will definitely be revising that number."

Copyright Reuters, 2018