Farmers in Northwest Iowa are rolling along with soybean harvesting with only about a third of the crop yet to be harvested. Iowa State University Extension Agronomist Joel DeJong says yields vary widely but are much better than expected.

He says the soybean yield variation ranges from 20 bushels per acre to 90 with a range of 50 bpa to 70 in the drier areas. DeJong says some stalk rot has shown up in the corn but the major concern is with forages and cover crops where army worms have been feasting.

Tar spot which has surfaced this year in Illinois and Indiana was seen in Northwest Iowa two years ago according to DeJong. He says while some Tar Spot was noted in the Ames, Iowa area, there have been no sign of it yet this year in Northwest Iowa. DeJong says producers should scout for it.

Tar Spot disease can cause significant yield loss in susceptible corn hybrids.