Chicago | Reuters – Chicago corn and soybean futures were mixed on Tuesday as an advancing U.S. harvest curbed price gains while traders awaited further developments in U.S.-Chinese trade negotiations.

Wheat edged higher for most of the session, with support from an Egyptian import tender that put the focus back on global demand and rising export prices. But Chicago wheat futures ended the day down on technical selling, traders said.

The Chicago Board of Trade most-active soybean contract fell 0.32 percent to $9.33-1/2 a bushel, while CBOT corn rose 0.59 percent to $3.86-1/4 a bushel.

CBOT wheat slipped 0.05 percent to $5.11-1/2 a bushel, holding above Monday’s low of $5.10.

U.S. farmers have harvested 62 percent of their soybean crop, up from 46 percent a week earlier although below the average pace of 78 percent at this time of the year, the U.S. Department of Agriculture said after the market closed on Monday.

The U.S. corn harvest was 41 percent complete, up from 30 percent a week earlier and lower than the average pace of 61 percent, the agency said. The corn harvest progress was below the average trade estimate of 43 percent.

Forecasts of snow across a wide swath of the U.S. Midwest – from Missouri to Wisconsin, according to the Commodity Weather Group – are poised to further slow the harvest and have raised questions about weather impacts on the U.S. corn crop.

The sluggish harvest helped firm basis bids for corn shipped by barge to the U.S. Gulf Coast on Monday, as photos of snow-covered Iowa fields began cropping up on Twitter this week.

“Everyone is wondering what the snow is doing to the corn harvest, particularly the corn that was planted later in the season,” said Ted Seifried, chief ag market strategist of the Zaner Group.

U.S. harvest yields are still seen as difficult to predict after a year marked by rain-plagued spring planting.

Meanwhile, soybean traders say the lack of news on the ongoing U.S.-China trade war has done little to boost prices. Progress this month in negotiations had raised hopes of a return to previous volumes of U.S. soybean shipments, although the market was awaiting firmer details.

“Everyone is more focused on weather right now and the fact that we’re in a vacuum of trade news,” said Mike Zuzolo, president of Global Commodity Analytics.

Soybean futures extended the day’s slump after Reuters reported that an interim U.S.-China trade agreement might not be completed in time for signing in Chile next month as expected. However, that does not mean the accord is falling apart, according to a U.S. administration official.

For much of the day, the wheat market was focused on a tender by top importer Egypt.

U.S. wheat remained uncompetitive and was not offered in the ongoing tender. But the U.S. market drew some support from initial bids that confirmed rising Russian prices and boosted Paris futures by showing French wheat as the cheapest origin before shipping costs.

– Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore