With drought expanding in the Midwest, the corn and soybean crops are in notably worse condition than a week ago, said the USDA Crop Progress report on Monday. The portion of the corn crop rated as good or excellent tumbled by 14 percentage points in Iowa and good/excellent ratings for soybeans plunged by 11 points in Illinois.

Iowa is the No. 1 corn state and Illinois is the national leader in soybeans. Last year, they combined to harvest 31 percent of the U.S. corn crop and 27 percent of the soybean crop. In the week ending on Sunday, 63 percent of the corn crop in Iowa rated as good or excellent, down from 77 percent a week earlier. In Illinois, 63 of soybeans were good/excellent, down from 74 percent the previous week.

Overall, 68 percent of the U.S. corn crop and 62 percent of the soybean crop was listed as good or excellent. A week earlier, 72 percent of the corn crop and 67 percent of soybeans were in the top two categories.

Weather in mid- and late summer usually is the determining factor in crop size, but dryness in the early months can have a lingering effect.

Nearly 57 percent of Iowa, mostly in the northern half of the state, was in drought, a 20-point increase in one week, said the Drought Monitor. Drought in the northeastern corner of Illinois expanded to cover 8.5 percent of the state. Aside from a few areas, there was “very little rain at all in the upper Midwest” in the week ending on June 8.