...."pictures" will speak louder than words.
From Manitoba Ag:
Soybeans
Due to the variability of the frost, the level of soybean injury has to be evaluated on a field by field basis. Generally frost injury is more severe on fields with heavy residue from previous crops.
When it comes to emerged soybean seedlings and freezing, size really does matter. While soybeans are sensitive to frost, the smaller the soybean plant the more tolerant they are to frost. Soybean plants that are just cracking through the soil (VE) and up to the cotyledon stage (VC) can tolerate -2.8°C for a few hours.
The most advanced soybean fields are between the cotyledon and unifoliate growth stage. Soybeans exposed to frost at the cotyledon stage may leaf out again, however, you will have to wait 3 to 5 days before going out to look for signs of new growth. At the cotyledon stage soybeans have three potential growing points: the main shoot and two axillary buds that are located at the base of the cotyledons. Under normal conditions the axillary buds never grow, but if the main growing point is killed by frost, the two axillary buds will start to grow within a week of the frost event. Under the current cool, cloudy conditions you may have to wait up to a week before you see any sign of recovery. During the summer, one of the axillary branches will become dominant and be the main stem of the soybean plant.
Soybean plants that were still below the soil surface were not affected by the frost and will emerge normally.
Even soybean fields that suffered a lot of frozen plants do not automatically have to be reseeded. Soybeans have a tremendous ability to compensate for reduced stand when scattered plants are removed, especially on fields seeded for a final plant population of 200,000 plants per acre or more. Soybeans cannot compensate for large areas of stand loss.
Opposite of what I thought might be the case.
But Klause, Maybe your drill that leaves the black furrow will help ward off the frost.
From Manitoba Ag:
Soybeans
Due to the variability of the frost, the level of soybean injury has to be evaluated on a field by field basis. Generally frost injury is more severe on fields with heavy residue from previous crops.
When it comes to emerged soybean seedlings and freezing, size really does matter. While soybeans are sensitive to frost, the smaller the soybean plant the more tolerant they are to frost. Soybean plants that are just cracking through the soil (VE) and up to the cotyledon stage (VC) can tolerate -2.8°C for a few hours.
The most advanced soybean fields are between the cotyledon and unifoliate growth stage. Soybeans exposed to frost at the cotyledon stage may leaf out again, however, you will have to wait 3 to 5 days before going out to look for signs of new growth. At the cotyledon stage soybeans have three potential growing points: the main shoot and two axillary buds that are located at the base of the cotyledons. Under normal conditions the axillary buds never grow, but if the main growing point is killed by frost, the two axillary buds will start to grow within a week of the frost event. Under the current cool, cloudy conditions you may have to wait up to a week before you see any sign of recovery. During the summer, one of the axillary branches will become dominant and be the main stem of the soybean plant.
Soybean plants that were still below the soil surface were not affected by the frost and will emerge normally.
Even soybean fields that suffered a lot of frozen plants do not automatically have to be reseeded. Soybeans have a tremendous ability to compensate for reduced stand when scattered plants are removed, especially on fields seeded for a final plant population of 200,000 plants per acre or more. Soybeans cannot compensate for large areas of stand loss.
Opposite of what I thought might be the case.
But Klause, Maybe your drill that leaves the black furrow will help ward off the frost.
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