Feekes Scale of Wheat Development

Leaf and Tiller Development

Stem Elongation

Head Development

Feekes 3 through 9

Double ridge. The primordia, which differentiate into spikelets, become visible after vernalization requirements are met. Floret initiation starts slightly above the middle portion of the microscopic head and moves outward. The number of florets initiated determines the potential number of kernels per head. 

Terminal spikelet. This stage marks the completion of the spikelet initiation phase. At this stage, the number of spikelets per head has been determined. Terminal spikelet occurs at Feekes 5. 

Head growth. Rapid head growth occurs in parallel with stem elongation during Feekes growth stages 6 through 9. Florets become ready for pollination and fertilization. 

Head emergence. Tiller development synchronizes with the main stem, so flowering occurs almost simultaneously in the main stem and tillers, regardless of differences in tiller initiation.

Heading and Flowering

Grain Filling

Ripening

From Kansas State University Agricultural Experiment Station and Cooperative Extension Service