By Ed Lentz
It has not been an easy year for many area wheat farmers.
Farmers who planted their wheat after Oct. 20 were caught with early wet and cold conditions, which delayed emergence and early growth. Then the plants had to battle a tough winter of rain, ice, and severe cold temperatures.
Many fields had standing water or ice on the surface throughout the winter, causing loss of stands and unhealthy plants.
Spring was not much better with abnormally wet conditions and cool temperatures. Wheat fields often become green the first part of March, but it was early April before greenup occurred in 2019.
There are wheat fields in the area that look good. These were generally planted before mid-October and did not have water standing for extended periods during the winter.
Since each growing season is different, agronomists and researchers have set up numeric scales to describe the different growth stages of wheat.
The most common scale used in this area is called the Feekes system. This scale uses a numbering system of 1 through 11 with each number representative of a new growth event.
A wheat field reaches a new growth stage when more than 50% of the plants are at the next stage.
The early stages may be collectively referred to as the vegetative stages since the growing point has not differentiated into reproductive tissue. The growing point is also below the soil surface and protected from above-ground environmental and pest issues during this time. These stages would include Feekes 1-5.
However, growth stage 5 may be called a transitional stage, since the tissue in the growing point has differentiated to include reproductive tissue in fertile tillers.
Collectively, Feekes 6-11 may be referred to as the reproductive stages. Photoperiod, the length of daylight, will trigger wheat to switch to reproductive growth about the same time each year. However, the calendar date for each growth stage will vary each year depending on temperature.
Feekes growth stage 6 occurs when the first node is visible above the soil surface.
To identify wheat at growth stage 6, remove several large tillers from the field that include the roots. Gently pull down the leaf blades and sheaths on the stem and look for the first node at the base of the stem.
This node will appear as a bump or area of a different shade of green on the lower stem. Sometimes it can be felt rather than seen. Farmers often call it a joint since it looks like an area connecting two parts of the stem; thus farmers may say wheat has jointed at this stage.
The growing point that will eventually develop into wheat head will be above the node. Eventually, four nodes will form by the time the grain head emerges from the stem.
There will be a leaf attached at each node. Thus, the grain stem will have four nodes and four leaves along its length at full emergence.
Feekes 6 is one of the most significant growth stages for wheat. At this time the plant has switched from vegetative to reproductive growth. Tillers are now susceptible to permanent injury since the growing point is now above the soil surface.
By this time, a farmer should have applied all of the nitrogen needed to ensure optimal yields. It is also a time when a farmer has to be careful on herbicide selection since many products can no longer be safely applied at Feekes 6 without causing injury or yield reduction.
Most of the wheat fields in the area had reached Feekes growth stage 6 about a week ago. At this time, two nodes may be found on the main wheat stem, which means the wheat is at growth stage 7.
With all the rain, farmers will be more concerned about foliar wheat diseases. Septoria and powdery mildew are the most common ones in our area.
These diseases move up the stem from the splashing of spores caused by rain. However, these diseases prefer cool temperatures, so if May becomes warm, these diseases will be less of a concern.
Farmers actively check their fields for disease when the wheat reaches growth stage 8. At this stage, the flag leaf, the last leaf to emerge from the stem, has just become to appear out of the whorl of the stem.
It is critical that farmers protect the flag leaf. The flag leaf provides most of the substrate for the developing grain. If the leaf below the flag leaf has two or more disease lesions at growth stage 8, a farmer may apply a fungicide to protect the emerging flag leaf.
Wheat heads generally emerge around the end of May, Feekes growth stage 10. At this time farmers become concerned about head scab infection and may apply a different fungicide for this disease.
Wet conditions increase risk of disease at all growth stages.
It has been a difficult spring for area farmers. Wheat fields planted early still have a chance for good yields. Late-planted fields suffered through the winter and may be torn up and planted to another crop.
However, rain has prevented all field activities, including applying herbicides and spring tillage.
A visual of wheat stages may be found on the following YouTube sites:
Feekes 7 & 8: https://www.youtube.com/watch?v=PZ7Lvsux1y8
Feekes 9 & 10: https://www.youtube.com/watch?v=OHGhq0qSM1o
Wheat heading: https://www.youtube.com/watch?v=Q6Da1HRlmV8
Lentz is extension educator for agriculture and natural resources for the Ohio State University Extension Service in Hancock County. He can be reached at 419-422-3851 or via email at email@example.com.
Lentz can be heard with Vaun Wickerham on weekdays at 6:35 a.m. on WFIN, at 5:43 a.m. on WKXA-FM, and at 5:28 a.m. at 106.3 The Fox.