If you’ve ever treated frozen seed, you know what a pain it can be. Seed treatment freezes to the seed upon contact (known as flash freezing), and doesn’t adhere to the seed properly. Later on it can flake off or get wet, causing issues with metering augers and rollers on air drills. It also leads to issues with seeding rate and generally causes lots of grief. Not a good situation.
Every seed treatment has its own requirements when it comes to ideal application temperature, but trying to tailor recipes based upon seed temperature is, of course, a messy and futile exercise. The logical way to tackle this problem is to ensure seed isn’t frozen when it’s treated.
After a tough harvest, seed is often aerated in order to condition it for storing, which makes it cold. The seed is put into a bin, where it stays until it’s treated in the spring. Trouble is, bins can be a great insulator. The seed stays frozen, and isn’t thawed prior to treating. And so the problems begin.
I’m lucky to be a member of a team that is working to tackle this problem by creating new coatings that can be applied to frozen seed without issue. One day, we may be able to offer a coating product to be used in the event that frozen seed arrives at a treatment facility or needs to be treated quickly on-farm. This product would be made of a material that will not flash freeze upon contact with cold seed.
I wish I could say such a product is soon to hit the market, but we’re not there yet. At the moment, the best way to avoid flash freezing of seed treatment is to ensure seed is warmed prior to treatment.
Keep seed in a heated shop overnight, or turn your fans on and blow warmer air onto it to bring it to a more ambient temperature. Even zero degrees or just above freezing is ideal.
In the event that frozen seed must be treated, adding some water to the seed treatment and bringing the application volume up can help with flash freezing and result in better adhesion. Consult product specifications before doing this, however.
Until a seed coating is developed that’s resistant to flash freezing, prevention is key to avoiding the problems that come with treating frozen seed.