WASHINGTON — Both corn and soybean harvests advanced in the week ended Sept. 28 but continued to lag five-year averages for the date, the U.S. Department of Agriculture said in its most recent Crop Progress report.

Progress in planting winter wheat in the 18 major states was ahead of the five-year average, as was emergence. The U.S.D.A. said 43% was planted as of Sept. 28 compared with 36% as the average. Fourteen per cent was emerged compared with 12% as the average.

Corn harvested in the 18 major states was 12% compared with 23% as the average. Top-producing Iowa was 2% completed as of Sept. 28 compared with 15% as the average. Illinois was 14% harvested in the latest week compared with 34% as the average.

Soybeans in the 18 major states were 10% harvested compared with 17% as the average, the U.S.D.A. said. Top-producing Iowa was 3% harvested compared with 17% as the average. Illinois was 7% harvested compared with 13% as the average.

The spring wheat harvest in the six major states was 94% complete as of Sept. 28 compared with 96% as the five-year average, the U.S.D.A. said.

Denting of the corn crop was 96% compared with 97% as the average. Sixty per cent of the crop in the 18 major states has reached maturation compared with 70% as the average.

Sixty-nine per cent of the soybean crop was dropping leaves as of Sept. 28 compared with 71% as the five-year average, the U.S.D.A. said.

Corn crop conditions in the 18 major states remained unchanged from the previous week at 74% good to excellent, 19% fair and 7% very poor to poor. Soybean conditions improved by one percentage point from the previous week, the U.S.D.A. said, with 72% rated good to excellent compared with 71% the previous week.