Cold, wet planting conditions: effect on sweet corn, beans, peas

Elaine Roddy, OMAFRA Vegetable Crop Specialist, Ridgetown

The soil temperature at time of planting can have a huge impact on the future growth and development of the crop.  Enzyme damage may occur when a dry seed absorbs cold water from the soil.  This damage can impact the speed at which the shoot and root emerge, even if the weather subsequently becomes more suitable for crop growth. 

Cold water damage to the seed can also reduce crop vigour for the rest of the early growth stages making the plants more prone insects and disease pressure.  These stresses often do not appear until the plant starts the rapid growth phase (3-5 leaves for sweet corn, 3rd trifoliate for beans).

Ideally we like to see the crop emerge within 7-10 days of planting.  See the table below for an outline of the time required for crop emergence at various different temperatures.

NG = no germination, – = not tested

[1] Maynard, D and G. Hochmuth, 1997.  Knott’s Handbook for Vegetable Growers, John Wiley and Sons Inc.