Pictures of Later Wheat Growth Stages

April 12, 2008 in Uncategorized

The following are pictures of later growth stages in wheat. It is important to know these different stages and the associated management decisions for each stage.

Feekes 8.0 Flag leaf visible

Feekes 9.0 Ligule of flag leaf visible.

Feekes 10.1 Boot stage, awns visible

Feekes 10.5.1 Beginning flowering

Feekes 11.0 Ripening

Images from Growth Stages of Wheat: Identification and Understanding to Improve Crop Management by Travis D. Miller, Professor and Extension Agronomist-Small Grains and Soybeans, Texas A&M http://sanangelo.tamu.edu/agronomy/wheat/whtmang.htm

Wheat Growth Stages – Flag leaf to Maturity

April 12, 2008 in Uncategorized

As wheat continues to progress, you will want to know what the growth stages are from flag leaf to maturity and what are the critical management decisions during those stages. The following is information on these later growth stages.

Feekes 8.0. Flag leaf visible

This growth stage begins when the last leaf (flag leaf) beings to emerge from the whorl. This stage is particularly significant because the flag leaf makes up approximately 75 percent of the effective leaf area that contributes to grain fill. When the flag leaf emerges, at least 3 nodes are visible above the soil surface; occasionally a fourth node can be found. 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.

At Feekes 8.0, the grower should decide whether to use foliar fungicides or not. This decision should be based upon the following considerations:

1) Is a fungal disease present in the crop?
2) Does the crop have resistance to the fungal disease, or is the disease spreading rapidly?
3) Does the crop yield potential warrant the cost of application of the fungicide in question to protect it?
4) 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, especially the emerging flag leaf, 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 stage 8.0 to 9.0. There is a considerable debate about pre-emptive applications of fungicides to prevent future infestations of fungal diseases. In certain high disease and high yield environments, this may be justified.

Nitrogen applications at Feekes 8.0 and later can enhance grain protein levels, but are questionable with respect to added yield.

If soils are dry, irrigation may be necessary at this stage. Irrigation scheduling becomes most critical between Feekes 8.0 and mid-grain (Feekes 11.1). The crop should not be stressed from about 10 days prior to bloom through the late milk stage. Feekes 8.0 marks a point in the development of the wheat plant beyond which every effort should be made to apply water to prevent loss in grain yield potential.

Feekes 9.0 Ligule of flagleaf visible.

Stage 9.0 begins when the flag leaf is fully emerged from the whorl. From this point on, leaves are referred to in relation to the flag leaf, i.e.; the first leaf below the flag leaf is F-I, the second leaf below is F-2, etc. The wheat plant typically produces 7 to 9 true leaves, not inclusive of leaves on the tillers. After flag leaf emergence, foliar diseases can seriously damage yield potential. True armyworms can feed on flag leaf and cereal leaf beetles can feed on flag leaf and cause yield loss.

Feekes 10.1 Boot stage, awns visible to Feekes 10.5.4 kernels watery ripe

The head is fully developed and can be easily seen in the swollen section of the leaf sheath below the flag leaf. The Feekes growth scale at stage 10 is divided as follows:
Feekes 10.0 boot stage
Feekes 10.1 awns visible, heads emerging through slit of flag leaf sheath
Feekes 10.2 heading 1/4 complete
Feekes 10.3 heading 1/2 complete
Feekes 10.4 heading 3/4 complete
Feekes 10.5 heading complete
Feekes 10.5.1 beginning flowering
Feekes 10.5.2 flowering complete to top of spike
Feekes 10.5.3 flowering complete to base of spike
Feekes 10.5.4 kernels watery ripe

Bloom occurs 4-5 days after heading.

Wheat is largely self pollinating. Most florets are pollinated before anthers are extruded. Although tillers have developed over a several week period, bloom in a given wheat plant is usually complete in a few days. After Feekes stage 10.5.3, remaining growth stages refer to ripeness or maturity of the kernel.

Soil moisture is critical during this period and irrigation may be necessary. Avoid irrigation during flowering to reduce head scab. If wheat is in boot stage and soils are dry, irrigate prior to flowering and then irrigate after flowering has completed.

Issues during head emergence, pollination, and seed set

>Head scab
>Foliar diseases of flag leaf and immediate leaves below reducing yield (powdery mildew, Stagonospora/Septoria, rust, tan spot)
>Glume blotch on heads (Stagonospora)
>Frost damage and blank heads
>Aphids in heads
>Grass sawfly clipping and some true armyworm clipping (armworm clipping is worse in later stages, grass sawfly clipping is more common at these stages)

Feekes 11.0 Ripening

Feekes 11.1 milky ripe
Feekes 11.2 mealy ripe
Feekes 11.3 kernel hard
Feekes 11.4 harvest ready

The grain fill period of wheat varies somewhat, depending upon climate. It is typically as little as 30 days in high stress environments, and may exceed 50 days in high yield, low stress environments.

The main pest problem in the early ripening stage is true armyworm doing head clipping. the main concern at late ripening stage is wet weather and head sprouting damage.

Extracted and modified from Growth Stages of Wheat: Identification and Understanding to Improve Crop Management by Travis D. Miller, Professor and Extension Agronomist-Small Grains and Soybeans, Texas A&M

Wheat Growth Stages in the Spring

April 2, 2008 in Uncategorized

The following is information on the spring growth stages in wheat and associated management decisions from Purdue University.

Jointing (FGS 6, DC 31) can be clearly determined. The original Feekes scale simply defined stage 6 as when the first node was visible at the base of the shoot. The Decimal scale provides a more precise definition for this stage, namely when the distance between the crown and the first stem node is at least 1 cm (0.4 in.). When the second above ground node is at least 2 cm (0.8 in.) above the first node, the plant has reached FGS 7 or DC 32. The ability to recognize FGS 6 is important because it’s the cutoff for many herbicides, especially those that contain 2,4-D, Axial, dicamba (Banvel, Clarity), MCPA, Olympus, Osprey, and Aim. Application of these products after jointing can result in malformed heads, sterility, and reduced yield. For a visual description of the cutoff date for various wheat herbicides, see page 151 in the 2008 Weed Control Guide for Ohio and Indiana or this link <http://www.btny.purdue.edu/Pubs/WS/WS-16/WheatTiming.pdf>.

The stage when the flag leaf first appears (FGS 8, DC 37) is important for application of a foliar fungicide. Stems of soft red winter wheat in Indiana typically have 4 above ground nodes when fully developed. The sheath of the uppermost leaf (flag leaf, F) arises from the top node. The leaf below the flag leaf (F-1) arises from the next node down, etc. Thus, leaf F-3 arises from the lowest above ground node. The lowest above ground node is near the ground when it first appears, but will move upward as the stem elongates. At FGS 8, there are usually two clearly differentiated nodes on the stem. The lower node will average about 7 cm (2-3/4 in.) above the soil line. The second node (from which leaf F-2 arises) will be about 15 cm (6 in.) above ground. The third node will usually be visible, but because it is only about 1 cm (0.4 in.) above node 2, it is not counted. As the wheat continues to grow, the distance between nodes increases, and the fourth node becomes evident. Feekes 8 (DC 37) is the cutoff for Harmony Extra, and Harmony GT, two products that are commonly used for control of wild garlic, and Express, commonly used for control of dandelion, chickweed, Canada thistle, and other winter annuals. Feekes growth stage 9 (DC 39) is the cutoff for Stinger, Starane, Widematch, and Buctril. Stinger is commonly used for control of Canada thistle, dandelion, and marestail; Buctril is commonly used for control of mustards, lambsquarters, ragweeds, and smartweeds.

Once the flag leaf blade has fully emerged, the flag leaf sheath extends. By this time, the head enclosed in this leaf sheath is swelling, and the plant enters the boot stage (FGS 10). The heads of all plants in a field will not emerge from the boot synchronously. Stages 10.1 through 10.5 are assigned according to when heads on about half the plants have reached the indicated degree of emergence.

Flowering in wheat begins roughly in the middle of the head and progresses both upward and downward. Flowering at a given position in the head can be judged by the presence of extruded anthers.

Ripening is judged by removing developing kernels from the center of several heads and determining whether the contents are watery, milky, or at the soft or hard dough stages.
By the time wheat has reached FGS 8, leaves F-5 and below are usually withered, from infection by Septoria, Stagonospora, and other fungi. The next leaf up (F-4) usually withers about the time heads have fully emerged. In the absence of Septoria and Stagonospora blotches, powdery mildew, or other foliar diseases, leaves F-3 through F should remain green until the wheat approaches maturity. Often, however, disease destroys leaves at each layer of the canopy prematurely. Fungicide control is aimed at maintaining these leaves, particularly F and F-1, in a healthy condition.

If a grower is planning to apply a fungicide at flag leaf emergence (FGS 8), it would be helpful to know when that stage will be reached, relative to some earlier, easily determined growth stage. The jointing (FGS 6) and 2-node (FGS 7) stages can be accurately determined if a wheat field is monitored frequently. The time required for a plant to progress from either of these stages to FGS 8 is not constant. It depends on weather, particularly temperature. Over many years, we monitored wheat crop development in various field trials, and the following observations can give some guidelines for the time required for plants to progress from one growth stage to another. It takes about a week to progress from FGS 6 to FGS 7, and another 8 days to go from FGS 7 to FGS 8 (with a range of 5 to 10 days). It can take from 3 to 8 days for the flag leaf blade to fully expand (going from FGS 8 to FGS 9). It can take from 9 to 16 days to progress from FGS 9 to full head emergence (FGS 10.5) or the beginning of flowering (FGS 10.5.1).

Extracted from “Identifying Wheat Growth Stages” by Gregory Shaner, Charles Mansfield, and Bill Johnson in the March 28, 2008 edition of the Pest and Crop Newsletter from Purdue Cooperative Extension Service.

What Growth Stage is Your Wheat in Now

March 15, 2008 in Uncategorized

Wheat management decisions should be based on the growth stage that the crop is in. The following is a description of the growth stages that wheat is in now or will be coming into in the next few weeks. Information is from Texas A&M University.

Feekes growth stage 4.0 Beginning of erect growth, leaf sheaths lengthen. Most tillers have been formed by this stage, and the secondary root system is developing. Winter wheats which may have a prostrate growth habit during the development of vegetative parts begin to grow erect. Leaf sheaths thicken. Nitrogen and herbicide applications can be made at this time. However, as most tillers have already developed, the number of heads is likely not going to be affected to a large extent.

Feekes growth stage 5.0. Leaf sheaths strongly erect. At this stage, the wheat plant becomes strongly erect. All meaningful tiller development has ceased. Many varieties of winter wheat which are creeping or low-growing during tillering, grow vertically at this stage. The vertical growth habit is caused by a pseudo or false stem formed from sheaths of leaves. At this stage of growth, the size of heads, or number of spikelets per spike, is determined. No effect on yield is expected from tillers developed after Feekes 5.0. Nitrogen applied at Feekes 5.0 can affect number of seed per head and seed size, but will not likely affect number of heads harvested. This is an ideal stage of growth for the spring topdress N application as later applications will not affect the potential number of seed per head.

Feekes growth stage 6.0. First node visible. This is called jointing. This stage of growth is easy to identify. Feekes 6.0 will not occur prior to the onset of cold weather, as vernalization is required in winter wheats prior to spikelet differentiation. Prior to Feekes 6.0, the nodes are all formed, but are sandwiched together so that they are not readily distinguishable to the naked eye. At 6.0 the first node is swollen and appears above the soil surface. Above this node is the head, or spike, which is being pushed upwards to eventually be exerted from the boot. The true stem is now forming. The spike at this stage is fully differentiated, containing all potential spikelets and florets or seed forming branches.

Growers should look carefully for the first node to emerge. It can usually be seen and felt. A sharp knife or razor blade is useful to split stems to determine the location of the developing head. The stem is hollow in most wheat varieties behind this node. By Feekes 6.0, essentially all weed control applications have been made. Do not apply phenoxy herbicides such as 2,4-D, Banvel or MCPA after Feekes 6.0, as these materials can be translocated into the developing spike, causing sterility or distortion. Sulfonyl urea herbicides (such as Harmony) are safe at this growth stage, but for practical reasons, weed control should have been completed by now.

Small grains can still show good response to N topdressed at this time, although yield responses will be better at Feekes 5.0 as head size can no longer be affected by fertilizer application. Mechanical injury to wheat can occur from fertilizer applicators at this stage of growth, but response to applied N will usually more than compensate for the damage if soil N is deficient.

Extracted from “Growth Stages of Wheat: Identification and Understanding to Improve Crop Management” by Travis D. Miller, Professor and Extension Agronomist-Small Grains and Soybeans, Texas A&M University.

Managing Wheat in a Year of High Prices – Effects of Winter Freeze and Thaw on Wheat and Wheat Fertilization

February 11, 2008 in Uncategorized

Winter warm and cold periods and freeze and thaw cycles can take their toll on wheat. This past weeks unseasonally warm weather followed by last nights freeze illustrates this point. The following is an article on the subject and on wheat growth stages and fertilization.

After a winter of periods of alternating mild and cold temperatures; snow, ice, and rain; and frequent day/night thaw freeze cycles, areas in fields or whole fields may be showing symptoms ranging from dead or dying plants to yellow to purple stunted plants. Winters characterized by a number of freeze-thaw cycles can lead to heaving that can force the grass crown out of the soil where desiccating winds can kill small susceptible seedlings and even larger established plants. The crown region of grass is a growing point region that produces new leaf buds; tiller buds; and, in the spring, new adventitious roots that form the spring root system. Until the new root system develops enough for the new roots to become active, little nutrition and possibly too little water is taken up by the plant. Injured plants may not show stress until the temperatures warm and they begin to grow. By about mid March, growers will begin to see these plants turn color and report that the small grain crop is ‘going backwards’. It is during the time when the plants begin to re-grow and new roots become functional that wheat and barley will look their worst.

Another symptom often visible at that time of year is where small grain leaves take on a purplish discoloration indicative of phosphorus (P) deficiency or sugar accumulation. More severe symptoms resulting in leaf injury and death can also be seen. Since P is necessary for the transformation of sugars to other compounds in the plant following photosynthesis, the cause and effect often become confused. Regardless, cold wet soil conditions, poor root growth early in the spring, and many other stress factors can lead to off color small grain crops early in the spring. To help overcome some of the stresses, be sure that your crop has adequate nitrogen (N) nutrition at or shortly after green up time.

Research at the University of Delaware and other locations has shown some yield responses to split N applications—usually averaging about 5 bu/A for winter wheat. You can take advantage of this yield response if your operation is set up to allow multiple or split N applications, and if the fields in question dry out quickly enough to allow the needed equipment on the fields both at green up and around the time the crop begins to joint (Feeke’s growth stage 5). A single N application is effective but best if it is applied shortly before or at crop green up. The initial N will be used by the crop to finish tillering and to produce a vigorous root system this spring. Late-season N applications at Feeke’s growth stage 5 will promote higher yield per kernel and increase the crude protein content of the grain but the N will have less effect on tiller number or ultimate plant height.

To distinguish between growth stage 3, when tillering is nearly complete and sheath elongation begins turning the plants upright, and growth stage 5, when jointing begins, you should carefully dig or pull several plants from the soil in a number of locations across the field. Carefully clean away excess soil from around the roots and plant base and remove any loose leaves and leaf sheaths from the base. A sharp knife can then be used to split the central stem down the center to look for the growing point. The growing point will be a conically shaped object about 1/8 inch or less in length that will be located near where the roots emerge from the stem base. If the crop is still at Feeke’s growth stage 3, the growing point will still be below the ground right against the stem base where the roots emerge. At Feeke’s growth stage 5, the stem internodes (the stem portion between stem nodes which are felt or seen as slight swellings in the stem) will have begun to elongate, moving the growing point upwards about a half inch to an inch above the stem base. As the first joint elongates enough to move the growing point above the soil surface and additional internodes begin to elongate, the crop will be at the beginning of growth stage 6.

Adapted from an article by Dr. Richard Taylor, Extension Agronomist, UD in the March 15, 2005 edition of the Weekly Crop Update.

Growth Stages in Wheat

January 23, 2008 in Uncategorized

It is important to know the growth stage of wheat, especially for herbicide and fungicide use decisions. The following is an article on the subject.

For effective management of wheat, it is important to recognize the stages of growth as the crop develops. Heading date is a common indicator of relative maturity, but the ability to recognize other growth stages is important for judging the progress of the crop and making management decisions, such as application of fertilizer, herbicides, or fungicides, and for predicting the consequences of disease or injury to the crop. The Feekes and Decimal (Zadoks) scales are the most common growth stage systems for wheat. The Feekes scale is older and has been used widely since the early 1950s. The Decimal scale is designed to make finer distinctions among stages of crop growth, and is probably used more in Europe than in the U.S., although pesticide labels in the U.S. are starting to use both scales.

The Feekes scale divides growth stages into 11 major categories. Head emergence, flowering, and grain filling (Feekes Growth Stages 10 and 11) are further subdivided. The Feekes Growth Stage scale is presented in Table 1 (on page 7), with a description of the crop development stage that corresponds to each number. The Decimal scale comprises 9 major divisions (1-9), with 10 possible subdivisions (0-9) for each major division. For example, the tillering stage is denoted by 2 in the Decimal scale, and the second digit indicates the number of tillers per plant. The Feekes scale simply notes whether tillers have begun forming (FGS 2), or whether tillering is essentially complete (FGS 3), without requiring the counting of tillers, although tiller number per plant could be appended after the “2”, e.g., FGS 2.4.

The most difficult task in describing crop growth stage is determining leaf number and tiller number. Accurate determination of leaf and tiller number requires that plants be dug up and carefully separated. To determine leaf number, position the plant so that the first true leaf is on the left. Because winter wheat has an opposite leaf arrangement the next leaf will be on the right side of the plant. By spring, the first 2 leaves may have died and withered, so the plant needs to be inspected carefully to find the remnants of these leaves. The next leaf would be counted only if that leaf was at least one-half the length of the preceding leaf. Continue counting leaves up the stem until the total number of leaves is determined. It is important that tillers be differentiated from leaves and counted separately. To distinguish tillers from a leaf look for the presence of an independent sheath, called a prophyll, which is located at the base of each tiller. Unlike leaves, tillers are counted as soon as they emerge. Once leaf number and tiller number have been identified, the subsequent key characteristics to be noted are node formation, flag leaf emergence, boot stage, head emergence, flowering, and finally grain development.

In winter wheat, the period from beginning of tillering to completion of tillering may extend for a considerable time, from autumn into the following spring. Likewise, the precise limits of FGS 4 and 5 are not clear. Depending on planting date, variety, and weather in the fall, plants may reach the pseudo stem erection stage in the fall, or only in the spring as the crop comes out of dormancy.

Jointing (FGS 6, DC 31) can be clearly determined. The original Feekes scale simply defined stage 6 as when the first node was visible at the base of the shoot. The Decimal scale provides a more precise definition for this stage, namely when the distance between the crown and the first stem node is at least 1 cm (0.4 in.), and we have included this in the growth stage table. When the second aboveground node is at least 2 cm (0.8 in.) above the first node, the plant has reached FGS 7 or DC 2. The ability to recognize FGS 6 is important because it’s the cutoff for many herbicides, especially those that contain 2,4-D, dicamba (Banvel, Clarity), MCPA, Olympus, Osprey, and Aim. Application of these products after jointing can result in malformed heads, sterility, and reduced yield.

The stage when the flag leaf first appears (FGS 8, DC 7) is important for application of a foliar fungicide. Stems of soft red winter wheat in Indiana typically have 4 aboveground nodes when fully developed. The sheath of the uppermost leaf (flag leaf, F) arises from the top node. The leaf below the flag leaf (F-1) arises from the next node down, etc. Thus, leaf F-3 arises from the lowest aboveground node. The lowest aboveground node is near the ground when it first appears, but will move upward as the stem elongates. At FGS 8, there are usually two clearly differentiated nodes on the stem. The lower node will average about 7 cm (2-3/4 in.) above the soil line. The second node (from which leaf F-2 arises) will be about 15 cm (6 in.) above ground. The third node will usually be visible, but because it is only about 1 cm (0.4 in.) above node 2, it is not counted. As the wheat continues to grow, the distance between nodes increases, and the fourth node becomes evident. Feekes 8 (DC 7) is the cutoff for Harmony Extra and Harmony GT, two products that are commonly used for control of wild garlic, and Express, commonly used for control of chickweed, Canada thistle and other winter annuals. Feekes growth stage 9 (DC 39) is the cutoff for Stinger, Starane, Widematch, and Buctril. Stinger is commonly used for Canada thistle, dandelion, and marestail control and Buctril for mustards, lambsquarters, ragweeds, and smartweeds.

Once the flag leaf blade has fully emerged, the flag leaf sheath extends. By this time, the head enclosed in this leaf sheath is swelling, and the plant enters the boot stage (FGS 10). The heads of all plants in a field will not emerge from the boot synchronously. Stages 10.1 through 10.5 are best assigned according to when heads on about half the plants have reached the indicated degree of emergence.

Flowering in wheat begins roughly in the middle of the head and progresses both upward and downward. Flowering at a given position in the head can be judged by the presence of extruded anthers.

Ripening is judged by removing developing kernels from the center of several heads and determining whether the contents are watery, milky, or at the soft or hard dough stages.
By the time wheat has reached FGS 8, leaves F-5 and below are usually withered, from infection by Septoria, Stagonospora, and other fungi. The next leaf up (F-4) usually withers about the time heads have fully emerged. In the absence of Septoria and Stagonospora blotches, powdery mildew, or other foliar diseases, leaves F-3 through F should remain green until the wheat approaches maturity. Often, however, disease destroys leaves at each layer of the canopy prematurely. Fungicide control is aimed at maintaining these leaves, particularly F and F-1, in a healthy condition.

If a grower is planning to apply a fungicide at flag leaf emergence (FGS 8), it would be helpful to know when that stage will be reached, relative to some earlier, easily determined growth stage. The jointing (FGS 6) and 2-node (FGS 7) stages can be accurately determined if a wheat field is monitored frequently. The time required for a plant to progress from either of these stages to FGS 8 is not constant. It depends on weather conditions, particularly temperature. Over many years, we have monitored wheat crop development in various field trials, and the following observations can give some guidelines for the time required for plants to progress from one growth stage to another. We found that it takes about a week to progress from FGS 6 to FGS 7, and another 8 days to go from FGS 7 to FGS 8 (with a range of 5 to 10 days). It can take from 3 to 8 days for the flag leaf blade to fully expand (going from FGS 8 to FGS 9). It can take from 9 to 16 days to progress from FGS 9 to full head emergence (FGS 10.5) or the beginning of flowering (FGS 10.5.1).

To correctly determine crop growth stage, identify the following characteristics in order.
1. Count the leaves on the main shoot
2. Count the tillers
3. Count the nodes
4. Flag leaf emergence
5. Boot stage initiated
6. Head emergence
7. Flowering or anthesis
8. Grain developmental stage

From the article “Identifying Wheat Growth Stages” by Gregory Shaner, Shawn P. Conley, and Bill Johnson in the April 13 , 2007 edition of the Pest and Crop Newsletter from Purdue University Extension.

Wheat Growth Stages – Feekes Scale, Early Growth

October 13, 2007 in Uncategorized

Feekes Growth Stage 1 – Seedling
Feekes Growth Stage 2 – Beginning Tiller

Feekes Stage 3 – Full Tiller

Fall Growth Stages in Wheat.

October 13, 2007 in Uncategorized

It is important to understand the different growth stages for wheat and the management practices that are critical during each period. The following are the fall growth stages.

There are at least five scales commonly used worldwide to describe stages of growth of wheat and other small grains. The scale used is not important, as long as the grower has a thorough understanding of the growth habit of wheat and how management inputs at specific growth stages can affect forage and grain yield.

Probably the most widely used scale in the U.S. is the Feekes scale, although the Zadoks and Haun scales are more detailed and descriptive. Careful study of the developing crop and an intimate knowledge of factors which may have positive or negative effects on forage and grain yield potential can enhance management decisions. These decisions can make wheat production more profitable.

This article discusses management of the wheat crop in terms of the Feekes growth scale and provides visuals of those growth stages.

Feekes 1.0 Emergence(one shoot formed)

If desired, number of leaves present on the first shoot can be designated with a decimal. For example, 1.3 is a single shoot with three leaves unfolded. Without a doubt, the most significant event in achieving high yield of grain and/or forage in wheat is stand establishment. Planting high quality seed of an adapted wheat variety in a fertile, well prepared seedbed with enough moisture to achieve a rapid, uniform stand is a significant step in achieving acceptable yields.

Late planted wheat has less time to tiller and should be planted at a higher rate to compensate for fewer tillers. If early forage production is a goal, producers should increase seeding rates and depend less on tiller formation to produce early forage growth.

Feekes 2.0 Beginning of tillering

A tiller is a shoot which originates in the axil of a leaf or at the coleoptilar node. Tillers share the same root mass with the original shoot or main stem. Once established, secondary tillers may arise from the axils of the primary tillers; tertiary tillers may develop from the axils of secondary tillers, etc.

During tillering, the major management consideration is whether stands are adequate to achieve yield goals. Management inputs will not compensate for skippy or erratic stands caused by insects, poor seed quality, herbicide injury, etc. If stands are thin, but uniform, an early nitrogen (N) application may enhance the rate of tillering, potentially increasing the number of heads per square foot. Care must be taken with fall N application. If heat units are available, excess N applied at this time leads to a lush, vegetative growth which makes the crop more susceptible to winterkill, foliar fungal disease, and aphid injury. Adequate phosphorus (P) is strongly related to rooting and tiller development. If tiller development is a historic problem in a given field, close attention must be given to P soil test recommendations prior to planting. Potassium (K) levels should be maintained at optimum levels to improve overwintering and for subsequent soybean crops. Harmony and Osprey herbicides can be applied at this stage.

Feekes 3.0 Tillers formed

Winter wheat can continue to tiller for several weeks. Depending upon planting date and weather conditions, tillering can either be interrupted by or completed prior to the onset of winter dormancy. Most of the tillers that contribute to grain yield potential are completed during this stage. Leaves begin to twist spirally. Many winter wheats are prostrate or “creeping” at stage 3.

Major yield potential loss can occur from weed infestation during tiller formation, as weeds compete for light, water and nutrients. Once the wheat has achieved full canopy, little problem is experienced from weeds. Weed control decisions should be made before or during Feekes 3.0. Some herbicides may be applied for postemergence grass and broadleaf weed control during this growth stage on tolerant wheat varieties. The herbicides 2,4-D, dicamba, and similar phenoxy herbicides should not be applied until wheat is fully tillered, or after Feekes 3.0. Growers should carefully scout for aphid and other insect infestations during Feekes 2.0 and 3.0, as stress from insect injury can reduce tiller formation. Control thresholds are much lower on small plants than later when plants are larger.

Extracted and modified from Growth Stages of Wheat: Identification and Understanding to Improve Crop Management by Travis D. Miller, Professor and Extension Agronomist-Small Grains and Soybeans, Texas A&M

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