Two different scales exist to identify the stages of wheat: the Feekes Scale and the Zadoks Scale. The Feekes Scale is the most commonly used, and the one I use when working with wheat.
If you’re unfamiliar with this scale, or if you need a refresher, this article is a summary of the Feekes stages. I find there is great value in understanding the scale and being able to apply it to your crop as it moves through the different wheat growth stages. This will help you make the best decisions about the timing of fertilizer, herbicide, insecticide, and fungicide applications in addition to helping you to identify and understand critical phases in your wheat crop, such as, jointing and flag leaf emergence. Using the skills to stage wheat will enable you to treat your crop in the ways that will most support its production and success, adding value to your land and operation.
Feekes 1.0: Plants in this stage are newly emerged. The number of unfolded leaves is represented by a number following the decimal. For example, a shoot with two fully unfolded leaves would be in the 1.2 Feekes stage.
Feekes 2.0: Plants in this stage are at the beginning of tillering. Tillers are shoots that develop at the leaf axil. In this stage, they share the main stem. As earlier articles have stated, the ultimate number of tillers depends on Nitrogen fertilization.
Feekes 3.0: In this stage, also known as the prostrate stage, wheat is “creeping.” Tillers are formed and plants will continue to tiller for many weeks. Stage 3.0 takes place in the late fall and early spring and may or not complete before winter dormancy. It is an important stage as the number of tillers formed contribute to grain yield potential.
Feekes 4.0: This stage is the beginning of erect growth. Stage 4.0 begins when plants break winter dormancy in March or April. In most cases, the bulk of the tillers have formed and growth is now directed upward. Leaf sheaths thicken. Insects and weeds can be a problem at this stage, so continued scouting of your acres is important. Topdress applications are made at this time or shortly prior, and fungicide, herbicide, or insecticide applications can be made as well depending on the pressures in your field.
Feekes 5.0: Plants in this stage, which will not take place before vernalization, are experiencing stem elongation and their leaf sheaths start to show strong erectness. Tiller development has come to a close. Any herbicide applications should have been made prior to this stage, which is notable since head size and the number of spikelets per head are determined here.
Feekes 6.0: This stage usually occurs during mid-to-late April. In this stage, plants will continue to grow upward and the first node becomes visible above the surface of the soil. If the stem is split, you will be able to see the head directly above the node. Importantly, no herbicide applications should be made at this stage due to the possibility of sterilization or distortion of the spike.
Feekes 7.0: During this stage, which usually occurs in late April or early May, the second node becomes visible and the spike experiences rapid expansion.
Feekes 8.0: This stage denotes a crucial time for a wheat plant as the flag leaf (last leaf) begins to emerge. The flag leaf, once emerged, contributes 75% of grain fill in the head. This stage is also when decisions about foliar fungicides should be made depending on the presence of disease. Insecticide applications should also be made if necessary.
Feekes 9.0: Plants in this stage have fully expanded flag leaves. Any fungicide applications should have been made prior to this stage. Insects, such as army worm, can pose a threat to our wheat.
Feekes 10.0: In this stage, the head of the wheat plant has completed its development. The head is considered to be in its boot stage.
The Feekes 10.0 stage progresses through sub-stages, indicated by a number following the decimal, as the head emerges, and additional sub-stages, indicated by another decimal and number set, as the plant progresses into reproductive stages.
- Feekes 10.1: The awns start to push through with the head following.
- Feekes 10.2: The head is one quarter emerged.
- Feekes 10.3: The head is one half emerged.
- Feekes 10.4: The head is three quarters emerged.
- Feekes 10.5: Heading is complete and the head is fully emerged.
- Feekes 10.5.1: Plants start to flower. This stage usually occurs 3-4 days after the head fully emerges and lasts only 3-5 days. Environmental conditions such as temperature and moisture are critically important during this stage as pollination begins in the center of the head.
- Feekes 10.5.2: Pollination is complete to the top of the head.
- Feekes 10.5.3: Pollination is complete to the base of the head.
- Feekes 10.5.4: The head is fully pollinated. Kernels in this stage when split contain a watery substance. They will progress into maturity in future stages.
Feekes 11.0: This stage is identifiable by the milky substance that fills the grain kernel. This stage typically occurs in early June.
- Feekes 11.2: Plants in this stage have kernels filled with a doughy or mealy substance.
- Feekes 11.3: In this stage, which usually occurs in late June, kernels are impenetrable. They are considered hard and their moisture levels will continue to decrease.
- Feekes 11.4: Plants in this final stage are ready for harvest. This stage typically occurs in the beginning of July, but may vary depending on weather conditions and wheat variety.
If you have any questions or concerns around determining the stage of your wheat crop, contact your local United Farmers Cooperative Crop Consultant or Field Sales Agronomist who are trained in this area and would be glad to work with you.