WASHINGTON — Estimated Sept. 1 corn stocks were up slightly, soybean stocks were up 3% and wheat stocks jumped 21% from a year ago, the U.S. Department of Agriculture said in its latest Grain Stocks report released Sept. 30.

Old crop corn stocks in all positions on Sept. 1 totaled 1,738 million bus, up 6,607,000 bus from 1,731 million bus a year ago and the highest Sept. 1 stocks estimate since 1,967 million bus in 2006. The record for Sept. 1 corn stocks was 4,882 million bus in 1987.

Old crop soybean stocks in all positions on Sept. 1 totaled 197 million bus, up 3% from 191 million bus in 2015 and compared with the record of 574 million bus in 2007.

The Sept. 1 stocks estimate constitutes carryover into the 2016-17 crop year for both corn and soybeans. The U.S.D.A. has forecast record large production of both crops in 2016.

Stocks of all wheat on Sept. 1 were estimated at 2,527 million bus, up 21% from a year earlier and the highest since 2,976 million bus in 1987. The record high Sept. 1 stocks number for wheat was 3,157 million bus in 1986.

The U.S.D.A. corn and soybean stocks numbers were below the average of trade expectations while the wheat estimate was above the trade average.