Originally written by Ruth Beck, former SDSU Extension Agronomy Field Specialist.
Management decisions in wheat production are almost always based on growth stages of the crop. So it is important for wheat producers to be familiar with these growth stages.
There are a number of different scales that are used to describe the stages of growth of wheat and other small grains.
The one most widely used in the US is the numerical Feekes scale. It begins at Feekes 1.0 or emergence and ends at 11.4 or when the plant is ripe and ready to harvest. When 50% of the plants reach a growth stage, the field is designated to be at that stage. There are times, particularly during heading, flowering and ripening when a growth stage is further divided up by adding a decimal point after the whole number. For instance Feekes 1.3 would describe a seedling plant with three leaves unfolded on a single shoot.
Feekes 2.0 or tillering describes plants that are setting tillers. Depending on the weather, tillering can continue for a number of weeks.
Feekes 3.0 is reached when the plant has completed tillering. Winter wheat is usually prostrate or creeping at this stage.
Feekes 4.0 describes the stage when the plant is completing tiller development and beginning to grow more upright. The leaf sheath will thicken during this phase.
At Feekes 5.0, the winter wheat plant becomes much more erect in growth and tiller development is finished. Further development of the winter wheat plant requires vernalization or a period of cool weather. The growing point is still below ground and differentiates at Feekes 5.0, forming the wheat head. The maximum size of the head and the maximum spikelet’s per spike are determined at this stage.
At Feekes 6.0 the wheat plant begins to elongate and the first node appears above the soil surface. The true stem is now forming and above the first node is the head or spike, which is being pushed upward as the stem elongates. The spike at this stage is fully differentiated, containing all potential spikelet and florets.
Feekes 7.0 is characterized by the rapid expansion of the spike and the appearance of a second node above the soil surface.
The flag leaf begins to emerge from the whorl at Feekes growth stage 8.0. When the flag leaf emerges, at least 3 nodes are visible above the soil surface and at times a fourth node can be found.
At Feekes 9.0 the flag leaf will be completely emerged from the whorl.
Feekes 10.0 is that stage when the developing head is seen in the swollen section of the leaf sheath below the flag leaf. The Feekes 10.0 stage is further divided up with decimal points. For example Feekes 10.1 is the stage when the tips of the awns begin to show above the flag leaf. Feekes 10.5 is when the head is completely emerged and Feekes 10.5.1 is the beginning of flowering.
Feekes 11.0 consists of the ripening stage of the wheat head. Feekes 11.1 is milky ripe and at Feekes 11.4 the wheat is ready to harvest.
View detailed information on growth stages of wheat including a comparison of the Feekes, Zadok and Haun scales.