Freeze Effect on New Alfalfa and Small Grains
Oct 14, 2019
Last week’s sudden drop in temperature had most of us scrambling for our heavier jackets and hats. We often get questions about what that first hard freeze is going to do to our fall planted crops. Read below to learn about the effect of the freeze on newly established alfalfa and small grains.
Seedling Alfalfa
New alfalfa at second trifoliate or older are more susceptible to freeze damage. Four or more hours of 26 F or lower temperatures can kill seedlings. Newly emerged seedlings, younger than second trifoliate, and seedlings planted with a companion crop have a better tolerance to freezing temperatures. If the trifoliate on your new alfalfa are yellowing and dying there is a good chance the growing points will not be able to recover, and you will need to re-drill into the damaged areas. If stands are less than 15 plants per square foot, consider re-drilling.
Wheat/Small Grains
In newly emerging wheat the crown is below the soil surface and protected. Some factors that can affect the extent of damage are plant growth stage, plant moisture content (moisture helps regulate temperature, a dry soil will cool off faster than a moist soil), and the duration of exposure. Things to look for after a freeze is the color of the leaves. The leaves will be anywhere from yellow to appear to be dying, depending on the severity of the freeze. If the growing point is not damaged and there are newly emerging green leaves, the wheat will recover in the spring with minimal yield loss.
For more information, or to schedule scouting on your fall crops, contact your Great Bend Co-op Agronomist today.
Seedling Alfalfa
New alfalfa at second trifoliate or older are more susceptible to freeze damage. Four or more hours of 26 F or lower temperatures can kill seedlings. Newly emerged seedlings, younger than second trifoliate, and seedlings planted with a companion crop have a better tolerance to freezing temperatures. If the trifoliate on your new alfalfa are yellowing and dying there is a good chance the growing points will not be able to recover, and you will need to re-drill into the damaged areas. If stands are less than 15 plants per square foot, consider re-drilling.
Wheat/Small Grains
In newly emerging wheat the crown is below the soil surface and protected. Some factors that can affect the extent of damage are plant growth stage, plant moisture content (moisture helps regulate temperature, a dry soil will cool off faster than a moist soil), and the duration of exposure. Things to look for after a freeze is the color of the leaves. The leaves will be anywhere from yellow to appear to be dying, depending on the severity of the freeze. If the growing point is not damaged and there are newly emerging green leaves, the wheat will recover in the spring with minimal yield loss.
For more information, or to schedule scouting on your fall crops, contact your Great Bend Co-op Agronomist today.