Feekes 7.0: Second Node Becomes Visible
This stage is characterized by the rapid expansion of the head and the presence of two nodes. One node should be between 1.5 to 3 inches from the base of the stem and the other should be about 4 to 6 inches above the base of the stem. These nodes are usually seen as clearly swollen areas of a distinctly different (darker) shade of green than the rest of the stem. Note: the upper node may be hidden by the leaf sheath – you may have to run your fingers along the stem feel it: if only one node is present, then your wheat is still at Feekes growth stage 6. Wheat will still respond to N applied at this time if weather has prevented an earlier application; however, mechanical damage may occur from applicator equipment. Feekes 7 and 8 identification video: https://www.youtube.com/watch?v=PZ7Lvsux1y8
Feekes 8.0: Flag Leaf Visible, but Still Rolled Up
This growth stage begins when the last leaf (flag leaf) begins to emerge from the whorl. This stage is particularly significant because the flag leaf makes up approximately 75 percent of the effective leaf area photosynthesis that contributes to grain fill. It is therefore important to protect and maintain this leaf heathy (free of disease and insect damage) before and during grain development. When the flag leaf emerges, three nodes are visible above the soil surface. To confirm that the leaf emerging is the flag leaf, split the leaf sheath above the highest node. If the head and no additional leaves are found inside, Stage 8.0 is confirmed, and the grower should decide whether or not to use foliar fungicides to manage foliar fungal diseases. This decision should be based upon the following considerations:
- Is a fungal disease present in the field?
- Is the variety susceptible or are weather conditions favorable (wet and humid) for rapid spread and development of the disease(s) found in the field?
- Does the crop yield potential warrant the cost of application of the fungicide in question to protect it?
- Is the crop under stress?
If a positive answer applies to the first three questions, and a negative response to the last, plans should be made to protect the crop from further damage. Check product labels and apply as soon as possible. In most situations, the greatest return to applied foliar fungicides comes from application at Feekes Stages 8-10. Nitrogen applications at or after Feekes 8.0 should only be applied if earlier applications were not made or if N losses may be large from excessive wet conditions. Late N applications may increase protein content but this is not important for yield or milling traits of soft wheats. Moreover, additional N may increase the severity of some foliar diseases, particularly the rusts, and damage from ground application equipment may lower yields.
Feekes 9.0: Ligule of Flag Leaf Visible
Stage 9.0 begins when the flag leaf is fully emerged, determined by a visible ligule. At this time, there will be four visible leaves along the stem including the flag leaf and the lower leaves are referred to in relation to the flag leaf (i.e., the first leaf below the flag leaf is the F-1, the second leaf below is the F-2, and so forth). After flag leaf emergence, yields may be reduced if heavy army worm infestations remove the upper leaves during early grain fill. Feekes 9 and 10 identification video: https://www.youtube.com/watch?v=OHGhq0qSM1o