Hail damage; potato leafhoppers in alfalfa

This information was summarized from a June 1 teleconference with ISU extension field specialists in crops.

  • During the past week hail was reported by 10 of the 14 field specialists statewide. In some areas the hail was so severe that special hail meetings are being held to help producers assess damage and discuss replant options.
  • Drift complaints are mainly Roundup drift from soybean to corn. Michael White (south central) reported that some suspected herbicide damage to ornamentals is caused by disease, insects, or environmental problems.
  • Postemergence herbicide applications are continuing and in some areas have been delayed by heavy rain. In wet fields, cultivation or chemical control has not killed the large weeds.
  • First-cut hay harvest is behind schedule, especially in the southern third of the state. Alfalfa and red clover are in full bloom. Potato leafhoppers and hopperburn are beginning to show up on alfalfa, according to Brian Lang (northeast), Carroll Olsen (southwest), and Michael White (south central), so scouting is important.
  • Spotty black cutworm damage was reported. Some fields were sprayed with insecticide. In some instances where there was significant loss of corn stand, replanting occurred.
  • High numbers of grasshopper nymphs were reported in several locations by Virgil Schmitt (east), and Tony Weiss and Joel DeJong (northwest).
  • Corn replanting, because of damage caused by wireworms, stalk borer, billbug, hop vine borer, and true white grubs occurred in a few scattered fields.
  • According to Jim Jensen, Mark Carlton, and Michael White (southeast and south central) soybean and corn planting is 95 percent finished in most southern counties. Estimates of the average growth stages for corn and soybean as reported by the 14 ISU Extension field specialists across Iowa are shown in the table. (Note: V1, V2, etc., refer to the vegetative stage; numerals refer to the number of visible leaf collars on the corn plant. For soybean, VE refers to the soybean just emerging from the soil; V1 and V2 refer to the number of fully developed leaf nodes, i.e., leaflets expanded above the top node).
Area Corn Soybean
Northwest VE V1
North central V6 V1
Northeast V4-V5 V1
East central V4-V5 V1
Central V6 V1
Southwest V6 V1
South central V3-V4 V1
Southeast V3 VE-V1

This article originally appeared on pages 101-102 of the IC-480(13) -- June 8, 1998 issue.

Updated 06/07/1998 - 1:00pm