What are the physical characteristics of an awn?

An awn is the spiky protuberance that extends from the head of the wheat plant out, almost like a porcupine’s quills. However, an awn is not an essential part of a wheat plant, and wheat can have an awn, be awnless or have a short awn, called an awnlette.

What do awns do?

This is a more complicated question, and there have been many, many scientific papers that delve into the significance of awns, especially as they relate to increasing yields.

What seems most clear is that awns do play a critical part in respiration and photosynthesis. The cells in the awns are photosynthetically active and can help the plant take in light over an expanded surface area. This is vitally important in areas where access to sunlight and nutrients is limited. Awns also deter seed-eating animals, including birds and some bugs, from taking away the grain from the plant, similar to other spiked methods of plant protection like thorns on a rosebush. In the wild, awns also help with seed dispersal. Spiky awns can enter the ground and propel seed grains up to an inch into the soil, helping the seed find purchase into the ground.

However, beneath the physical features of an awn, it has another fascinating characteristic — a wheat plant with an awn develops a larger wheat grain. This is opposed to a wheat plant without an awn, which increases the number of grains in each head. However, despite having more total grains, a plant without awns is also likely to produce grains that are smaller. This provides an interesting opportunity for scientists to combine different lines between the two kinds of wheat, thereby taking advantage of the increased size of awn grains and the increased number of awnless grains.

Why are awns important?

So we come back to the most important question. Awns provide an important method of taking in sunlight and nutrients, especially in difficult environments. Awns also provide a method of protection against predators seeking to take grains away. In addition, they help plant seeds deeper into the soil to help the next generation of plants along.

Scientists are currently examining the role in which awned versus awnless versus awnletted wheat can play in increasing yield potential. Knowing that each region is unique and faces its own difficulties, scientists can develop individual varieties to maximize yield potential based on whether that environment favors some version of awned or awnless wheat. Now that’s Fit For Your Operation!

What do you think of the awn versus awnless conversation? Have you found one to be more productive in your fields over the other? Did we overlook another important aspect of having an awn? Let us know by connecting with us on Facebook, Twitter and Instagram!