This information was summarized from a June 11 teleconference with Iowa State University extension field specialists in crops.
- Corn planting is completed in most areas of the state, with plants ranging from the V4 through V7 leaf stage. Soybean planting is nearly completed (85 percent or more) in most areas, except southeastern and south central Iowa (35-40 percent planted) due to wet soils.
- Post herbicide damage to corn may be common this season. See the June 11, 2001, ICM newsletter article for more information on herbicide injury to stressed corn.
- Alfalfa is in full bloom. Approximately 30 percent of the hay has been cut in Iowa. Hay quality will be reduced due to late cutting attributable to the weather.
- Variegated cutworms were found in alfalfa in southeastern, south central, and central Iowa. Hopperburn from potato leafhoppers is showing up on new alfalfa and in older stands. Black cutworm damage reports were especially common in the northern half of the state. White grub problems continue in northwestern Iowa and have resulted in some replanting. Armyworm feeding was reported in alfalfa and corn in southwestern Iowa.
- Soybean should begin to develop tolerance to Phythium root rot by the first or second trifoliate leaf stage. Death of soybean plants from root rot after this stage is more commonly due to Phytophthora.
- Holcus leaf spot has been found on corn. See article in this issue on pages 111-112 for more information on holcus leaf spot.
- Nitrogen losses through denitrification and leaching may be large in some areas of the state this year. With above-normal precipitation it is appropriate to make downward adjustments in the soil nitrate critical level.
This article originally appeared on page 115 of the IC-486(14) -- June 18, 2001 issue.