Frost injury occurred Saturday May 29 across much of the area. Radiational frost occurs when leaf temperatures actually reach lower temperatures than nearby recorded air temperatures.
Frost has occurred
- along field edges - especially corn fields
- low areas
- no -till soybean fields - where crop residue insulated soybean plants from soil warmth
corn crop recovery can be expected
- most corn is in the V3- V4 development stage.
- the growing point is above ground level at the V6 stage
- however, frost does some strange things and corn can be killed at the developmental stages that precede the V6 stage.
- frosted leaves/dead leaf tissue will cause plants to wrap and therefore reduce the rate of recovery
- look for new white roots and new leaf tissue
- frost injury to soybeans is obvious after 3-4 days.
- soybean plants with green cotyledons/seed leaves may recover
- there are two growing points at the axils of the cotyledons
- new growth should be evident at the cotyledon leaf axils 5-6 days after the frost event
- consider delaying herbicide application until one new corn or soybean leaf develops -if frost injury has affected a large proportion of the field.
- However, crop safety of the group 27/HPPD herbicides should not pose a major crop injury potential.
- consider replant if corn populations are less than 20,000 plants/acre.
- consider replant if soybean populations are less than 60,000 plants/acre