Assess frost injury, crop recovery

June 1, 2021 10:51 AM
Blog Post

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

soybean recovery

            - 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

herbicide application

            - 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.

replant considerations.

            - consider replant if corn populations are less than 20,000 plants/acre.

            - consider replant if soybean populations are less than 60,000 plants/acre

 

​​​​injury to corn from frost in Clay county Iowa

 

injury to soybean from frost in Clay county Iowa

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Paul Kassel Field Agronomist in NW Iowa

Paul Kassel provides research based crop production information to area farmers and agribusiness. Educational programs are available for farmers, agribusiness, pesticide applicators, and certified crop advisors.

Areas of expertise include soil survey, crop production, soil fertility, so...