Test Overview
The Tray Cold Test, traditionally known as the Iowa Cold Test, is a vigor test used to evaluate a seed lot's ability to emerge following exposure to cold, wet conditions.
Developed at Iowa State University, the Iowa Cold Test has a long history of use for evaluating corn seed and may also be used for soybean, cereals, and other crops.
The traditional Iowa Cold Test uses a sand and soil mixture over the seed. A sand-only version is also available. Eliminating soil reduces variability associated with soil type and naturally occurring microorganisms and generally provides a more standardized, less biologically stressful test.
Test Details
Seeds are planted in trays containing a moist growing substrate and covered with either a sand/soil mixture or sand only.
The trays are exposed to cold conditions, typically 10°C (50°F), and are then moved to 25°C (77°F) to allow seedlings to emerge and develop.
The traditional test uses a seven-day cold period followed by a warm growing period. A shorter test using three days of cold exposure followed by four days under warm conditions may also be available.
Seedlings that emerge through the covering material are evaluated for normal development using vigor-testing criteria.
Which Tray Cold Test Should I Choose?
Iowa Cold Test (sand/soil): Provides additional biological stress from the soil component and is the traditional method used at Iowa State.
Sand Cold Test: Uses sand without soil, reducing variability associated with soil and microorganisms. This provides a more standardized test with somewhat less biological stress.
Contact Customer Care if you are unsure which method is most appropriate for your seed.
Sample Requirements
A minimum of 200 seeds are required to conduct the test. Please submit at least 300 seeds to provide sufficient seed for testing.
Additional seed is required if other tests are requested on the same sample.