Malt Cultivation

Growing barley is more than just sowing seeds and hoping for the best. It’s a process that needs careful planning, especially when the barley is destined for malting—the process that turns barley into malt for brewing beer and other drinks. Maltsters, the folks who make malt, want all the barley grains to be as similar as possible so they sprout at the same time. This means that farmers need to make sure their entire barley crop matures at the same rate.

Now, you might think that richer soil would produce better barley, but that’s not the case. Soil that’s too rich can make the barley grow unevenly. That’s why the best barley tends to come from lighter, airy soils that are ideally a bit chalky. Sometimes, to get the soil just right, farmers grow wheat before planting their barley.

Barley plants don’t have deep roots, so the nutrients they need should be in the top layer of the soil. That top layer should also be free of weeds and broken down into fine particles. Usually, barley follows a crop like turnips in the crop rotation plan because turnips help to “clean” the soil. After the turnips, the field often gets a visit from sheep, who naturally fertilize the soil as they graze. Then the soil is plowed, but only a little—just enough to mix in the sheep’s natural fertilizer without burying it too deep for the barley to reach.

When it’s time to sow the barley seeds, usually around March or April, farmers have to be picky about the seeds they use. The best seeds are light-colored and have fine wrinkles on their skin. The seeds are sown using a drill, which helps place them evenly and at the right depth in the soil. Sometimes, if the soil isn’t rich enough, farmers add some extra nutrients, but they have to be careful. Too much nitrogen can make the barley too rich in protein, which can cause problems later when the barley is stored or used for malting.

Once the barley is growing, it might get some light maintenance like rolling or harrowing to keep the soil fine and crumbly. When it’s time to harvest, the barley is cut when it’s fully ripe and the ears bend over. After cutting, the crop might be left out in the field for a bit to soak up some sun and dew, which can improve its color and texture.

In a rural setting, you can often find people discussing the best way to harvest barley. Some prefer stacking the grain without tying it into bundles, but this approach can be labor-intensive, both in moving the grain and in threshing it later. Others are hesitant to use machinery like binders for harvesting barley. They worry that tightly tied bundles won’t dry evenly in the sun, affecting the color of the grain.

Even when technology like harvesters are available, old habits sometimes die hard. For instance, if the barley is damp, it’s common to tie it in sheaves and set it upright, much like wheat, to allow it to dry properly. While there are generally accepted ways of growing barley, these methods often get adjusted based on local traditions or urgent farming needs.

As with wheat, barley isn’t without its problems. It is susceptible to various diseases, including smut, which is a type of fungal infection, as well as pests similar to those that plague wheat crops. In the late 19th century in Britain, an insect called the ribbonfooted cornfly wreaked havoc on barley, especially because the plants were already weakened from drought.

When it comes to yield, a good barley crop can produce around 36 bushels per acre. However, with optimal conditions, farmers can expect up to 50 bushels. While the grain is valuable, the straw that’s left over isn’t as useful. Compared to other types of straw, barley straw is often considered less ideal for use as animal feed or bedding.

Malt Growth Scales

Key wheat management decisions need to be made at certain growth stages. Exact growth stages cannot be determined by just looking at the height of the crop or based on calendar dates. A careful examination of the developing crop is needed to tell growth stages apart. Correct growth stage identification and knowledge of factors that affect grain yield can enhance management decisions, avoiding damage to the crop and unwarranted or ineffective applications. These decisions can make wheat production more profitable. Several scales can be used to identify wheat growth stages, including the Feekes and Zadoks scales. Here we focus on the more common Feekes Growth Scale.

Using this scale, growth stages are identified and assigned numerical codes based on the occurrence of key developmental events such as tillering, leaf and head emergence, and flowering. Since growth and development usually vary among tillers and across the field, it is important to sample and examine primary tillers at multiple locations to come up with a representative growth stage for the field. Commonly used sampling schemes include walking and examining tillers across the field at regular intervals along a zig-zag or M-shaped pattern, but the uniformity of the field and visual differences in crop development are also very useful for determining how and where to sample tillers. Usually the crop (or a section of a field) is said to be at a given growth stage when approximately 50 percent of the primary tillers reach that growth stage.

Wheat morphological terms.

Anther                  The male (pollen-producing) part of the flower.

Awn                      The bristles on the wheat head (spike).

Coleoptile            Protective sheath covering the emerging shoot.

Flag leaf              The last leaf to emerge before the head (spike).

Floret                    Each individual flower (containing anthers & stigma). Several florets form a single spikelet.

Spike                     Also known as the wheat head.

Spikelet                The basic unit of a wheat flower. Each spikelet consists of at least three florets.

Stigma                  The female (pollen-receptor) part of the flower.

Tiller                     A shoot originating from the main stem from the coleoptilar node.

Feekes Growth Cycle

Feekes Growth Scale

The Feekes Growth Scale is a scientific tool used to quantify and describe the growth stages of cereal crops, notably wheat, barley, and other grains. Developed by Willem Feekes, a Dutch agronomist, the scale helps researchers, agronomists, and farmers to determine the most appropriate times for fertilizer application, pesticide treatment, and other agronomic practices. In other words, it serves as a roadmap that allows stakeholders to monitor the life cycle of cereal crops in a standardized way. This precise monitoring is pivotal in influencing crop yield and quality, as well as in identifying any growth irregularities that might warrant intervention.

Understanding the Feekes Growth Scale necessitates a closer look at its classification system, which is characterized by numerical stages that delineate a crop’s progress from germination to maturation. These stages range from 1 to 11, with several stages further divided into sub-stages. For instance, the scale commences with Stage 1, which signifies that germination has occurred and the sprout has emerged from the soil. As we move through the scale, we encounter key developmental milestones such as tillering, stem elongation, and flowering, all the way to Stage 11, which indicates that the crop is ripe and ready for harvest. Each stage serves as a critical juncture where particular agronomic actions can maximize a crop’s potential.

While the Feekes Growth Scale may appear straightforward, interpreting its implications for agricultural practices is a nuanced endeavor. One of the most crucial applications is in the timing of nutrient application. In general, fertilizers are best applied during periods of active growth to optimize nutrient uptake. For example, nitrogen, which is essential for protein formation in cereal grains, is commonly applied during the tillering and stem elongation phases, corresponding to Feekes stages 2-5 and 6-9, respectively. Timing fertilizer application with these stages ensures that the crop utilizes nutrients efficiently, thereby optimizing yield and nutritional quality.

Similarly, the Feekes Growth Scale aids in the judicious use of pesticides. Certain pesticides have developmental restrictions, meaning they are only effective or safe to apply during specific growth stages. For instance, applying herbicides during the early tillering stage (Feekes Stage 2-3) may be appropriate for weed control without causing undue harm to the cereal crop. On the other hand, using the same herbicides during the booting or flowering stages (Feekes Stage 10) could have deleterious effects on the crop and might even violate regulatory guidelines.

Yet another application is in disease management. By understanding the growth stages when a crop is most susceptible to particular diseases, farmers can implement preventive measures, such as fungicide applications, more effectively. For example, Fusarium head blight, a disease that affects wheat, is most problematic during the flowering stage. Knowing that this corresponds to Feekes Stage 10.5 allows farmers to apply fungicides with optimal efficacy.

Though it offers a wealth of advantages, the Feekes Growth Scale is not without limitations. One significant drawback is that the scale was initially designed for temperate cereals, making its application to tropical cereals or other crops less straightforward. Additionally, while the scale does provide a general framework, it does not account for the influence of environmental factors such as soil quality, water availability, and climatic conditions on crop growth. Therefore, it is often used in conjunction with other growth scales and diagnostic tools for a more comprehensive understanding of crop development.

In summary, the Feekes Growth Scale is an instrumental tool in cereal crop management, aiding in the optimization of various agronomic practices such as nutrient application, pesticide use, and disease control. By standardizing the way we understand and describe cereal growth stages, it brings clarity and scientific rigor to agricultural operations. However, like any tool, it is most effective when used in context and in conjunction with other agricultural assessment methods. Thus, while the Feekes Growth Scale has been widely adopted and is considered a cornerstone in cereal crop management, it represents just one component in the intricate mosaic of modern agriculture.

Stages 1-4: Leaf & Tiller Development

Feekes Stages 1-4

GERMINATION
In the germination phase, seeds take in both oxygen and water, initiating the emergence of root structures. The process is most efficient when occurring in an environment with temperatures ranging from 54 to 77 degrees Fahrenheit. During this early stage, the application of seed treatments like fungicides and insecticides can be beneficial for controlling diseases that might otherwise compromise the seedling’s health

FEEKES 1.0: EMERGENCE
The number of leaves present on the first shoot (main stem) can be designated with a decimal. For example, 1.3 is a single shoot with three leaves unfolded. The most significant event in achieving high yields is stand establishment, i.e, the number of plants or tillers per square foot. 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 (USUALLY IN FALL)
A tiller is a shoot that originates in the axil the coleoptilar node. Tillers share the same root mass as the main stem. During tillering, the major management consideration is whether stands are adequate to achieve yield goals. Management inputs will not compensate for skimpy or erratic stands caused by insects, seedling diseases, poor seed quality, herbicide injury, etc. If stands are thin, but uniform, an early nitrogen (N) application of about 20 to 30 pounds per acre, may enhance the rate of tillering, and potentially increase the number of heads per square foot.  Care must be taken with fall nitrogen application. Excess Nitrogen applied at this time leads to a lush, vegetative growth which makes the crop more susceptible to winterkill and 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.

FEEKES 3.0: TILLERS FORMED (LATE FALL OR EARLY SPRING)
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. The herbicide metribuzin may be applied for postemergence grass and broadleaf weed control during this growth stage on tolerant wheat varieties. In most cases, plants should have at least 4 tillers and be actively growing before application of this herbicide. The herbicide 2,4-D 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.

WINTER DORMANCY
The onset of winter hardiness in winter wheat is prompted by a decline in air temperatures and reduced daylight hours. This process is known as vernalization, or winter dormancy, which necessitates a period of three to eight weeks with temperatures falling below 50 degrees Fahrenheit.

FEEKES 4.0: BEGINNING OF ERECT GROWTH (MARCH-APRIL)
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 earlier vegetative developmental stages, begin to grow erect at Feekes 4. Leaf sheaths thicken. The key management step at Feekes 4.0 is continued scouting for insects and weed infestations.

Stages 5-10: Stem Elongation

Stages 5-10: Stem Elongation

FEEKES 5.0: LEAF SHEATHS STRONGLY ERECT (EARLY- TO MID-APRIL)
Further development of the winter wheat plant beyond Feekes 4 requires vernalization, or a period of cool weather between Feekes 1 and Feekes 4. After the appropriate amount of chilling, followed by the resumption of growth, the growing point (located below the soil surface) differentiates. 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 this stage can affect the number of seeds per head and seed size, but not the number of heads per square foot or the number of spikelets per head. This is an ideal stage of growth for the spring topdress Nitrogen application.

FEEKES 6.0: FIRST NODE VISIBLE (MID-LATE APRIL)
Prior to Feekes 6.0, the nodes are all formed but sandwiched together so that they are not readily distinguishable. At 6.0, the first node is swollen and appears above the soil surface. This stage is commonly referred to as “jointing.” Above this node is the head or spike, which is being pushed upwards eventually from the boot. The spike at this stage is fully differentiated, containing future spikelets and florets. The first node can usually be seen and felt by removing the lower leaves and leaf sheaths from large wheat tillers. 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.

FEEKES 7.0: SECOND NODE BECOMES VISIBLE (LATE APRIL-EARLY MAY)
At Feekes 7.0 growth stage, the second node becomes visible. This stage is characterized by the rapid expansion of the head and a second detectable node. Look for the presence of two nodes—one should be between 1.5 and 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; If only one node is present, the wheat is still at Feekes Growth Stage 6. Wheat will still respond to nitrogen applied at Feekes 7.0 if weather prevented an earlier application; however, mechanical damage may occur from applicator equipment.

FEEKES 8.0: FLAG LEAF VISIBLE, BUT STILL ROLLED UP (LATE APRIL-EARLY MAY)
This growth stage begins when the last leaf (flag leaf) begins to emerge from the whorl (Figure 4). This stage is particularly significant because the flag leaf makes up approximately 75 percent of the effective leaf area 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 early-season and overwintering foliar fungal diseases.

 FEEKES 9.0: LIGULE OF FLAG LEAF VISIBLE (EARLY MAY)
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 10.0: BOOT STAGE (MID-MAY)
At the boot stage, the head is fully developed and can be easily seen in the swollen section of the leaf sheath below the flag leaf. This is another important growth stage for making fungicide applications for foliar disease management, particularly late-season diseases such as Stagonospora leaf and glume blotch and rusts.

Stages 10.1 - 11.4: Heading & Flowering, Grain Filling, Ripening,

Stages 5-10: Stem Elongation

FEEKES 10.1-10.5: HEADING (MID- TO LATE-MAY)
Heading marks the emergence of the wheat head from the leaf sheath of the flag leaf, and is subdivided into stages based on how much of the head has emerged.

  • 10.1    Awns visible, head beginning to emerge through slit of flag leaf sheath.      
  • 10.2    Heading one-quarter complete.      
  • 10.3    Heading one-half complete.      
  • 10.4    Heading three-quarters complete.      
  • 10.5    Heading complete.

FEEKES 10.5.1-10.5.3: FLOWERING (MID-MAY TO EARLY-JUNE)

  • 10.5.1    Beginning flowering. This stage is often marked by the extrusion of anthers from florets in the center of the spike (Figure 8). For that reason, this growth stage is also referred to as “anthesis.” Although, on rare occasions under growing conditions in Ohio, flowering may occur without anthers being extruded or with anther extrusion occurring after flowering, depending on the weather and the variety. Feekes 10.5.1 is the growth stage at which fungicides are recommended and are most effective against wheat head scab and vomitoxin.        
  • 10.5.2    Flowering complete at the top of the spike.      
  • 10.5.3    Flowering complete at the base of the spike.      

Wheat is self-pollinating. Most florets are pollinated before anthers are extruded. Although tillers have developed over several weeks, bloom in a given wheat plant is usually complete four to five days after heading. The grain-fill period of wheat varies somewhat, depending upon climate. It is typically as little as 13 days in high-stress environments, and may exceed 20 days in high-yield, low-stress environments. After Feekes Stage 10.5.3, remaining growth stages refer to ripeness or maturity of the kernel.

 

FEEKES 10.5.4-11.4: RIPENING AND MATURATION      

  • 10.5.4    Kernels watery ripe, clear fluid can be squeezed from the developing kernel.
  • 11.1    Milky ripe, milk-like fluid can be squeezed out of the kernels when crushed.     
  • 11.2    Mealy ripe, material squeezed out of the kernel has a doughy consistency.     
  • 11.3    Kernel hard, but dividable with thumbnail (late June).
  • 11.4    Harvest ready. Kernel is hard and not dividable with thumbnail (late June-early July).

At maturity, timely harvest is important. Risks of delayed harvest include disease, lodging and seed sprouting which ultimately reduce grain yield and test weight.

Based on an article by author: James E. Beuerlein, retired. (Originally published in 2001.)

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