Kernel to Kernel

The Growth Cycle of Kansas Winter Wheat

Kansas farmers are busy planting the next winter wheat crop, but harvest is not until next summer. What happens between now and then? 

The wheat will sprout and grow, before going dormant over winter. In the spring, it will grow again, all the way to the combine finish. 

This means the winter wheat plant must withstand all four seasons – and all the crazy Kansas weather.  

According to the K-State Wheat Production Handbook, “This hardiness is essential for wheat to endure the freezing temperatures of winter, the late frosts of spring, the high temperatures of June and the droughts that can occur anytime.” 

Seeding

Planted in late September or October, a wheat seed begins germination (begins to grow) by absorbing water and oxygen, requiring enough water in the soil and the right temperature. 

The seed develops and sends tillers, or shoots, up through the soil’s surface. These tillers need to be above ground and well established before the first frost hits. 

As the fall progresses, shorter days and gradually falling temperatures signal that winter is coming and the plant eventually goes dormant. 

During dormancy, the wheat plant conserves energy by temporarily slowing down or stopping growth and development. 

This stage – called vernalization – is a necessary part of the plant’s development. According to K-State, “winter wheat not only resists freezing temperatures during winter, it needs the cold to joint and flower so it can set grain in spring.” 

Tillering

Rising temperatures in late winter signal the wheat plant to “green up” and resume growing, called tillering. The past fall’s tillers grow rapidly and start to stand more upright. 

Jointing & Booting

Once the tillers finish growing, the wheat plant moves into the jointing phase. Nodes develop that will eventually reveal the leaves of the plant. The subsequent boot phase reveals the wheat head, which contains the kernels, still hidden inside the top of the plant. 

Heading 

When the “spike” emerges, the wheat is heading. Within a week, the plant will flower, pollinate and start to fill the kernels. By this stage, the final number of kernels is determined. 

Maturity 

The wheat plant will grow to its maximum height and weight, which could last between four and 12 weeks depending on weather.  

Kernel development is classified according to the consistency or hardness of its endosperm, the largest part of the seed that will eventually become flour. At first, the endosperm has the color and consistency of milk. As the kernel fills, the endosperm thickens into first a soft and then a hard dough, easily observed by chewing the kernel. 

Also in the early summer, the wheat plants change color, shifting from green to gold. The most important part of this stage is the loss of moisture, from 30 to 35 percent water at maturity to 12 to 13 percent when combines are ready to roll. 

By June or July, Kansas farmers will harvest the wheat they planted 10 months earlier. Each bushel, weighing about 60 pounds, will contain approximately one million individual wheat kernels. From kernels to flour, consumers around the world will eat bread, flat breads, tortillas and even noodles made with that good, hardy Kansas winter wheat. 

by Julia Debes

For more information about wheat growth, visit http://www.ksagclassroom.org/.