Wheat Life Stages: Planting, Growing, Harvesting

Wheat, a staple crop central to human civilization, undergoes a remarkable journey through its stages of life, each phase vital to its ultimate harvest. The journey, while somewhat variant across different varieties, follows a fundamental pattern:

Planting marks the inception of this journey, with winter wheat sown in September or early October, capitalizing on the soil's moisture for germination. Conversely, spring wheat eagerly takes root as soon as temperatures permit in the spring, heralding the start of its growth cycle.

The growing stage witnesses the resumption of growth for winter wheat in the spring, as the plant readies itself for reproduction. The stem diligently pushes upwards, unfurling the head where kernels, the essence of wheat, begin to form. With flowering commencing, the kernels embark on their maturation journey, signaling the onset of the next phase.

Harvest, the culmination of months of toil and nurture, arrives when the kernels reach optimal ripeness. Combines, the modern-day reapers, meticulously gather the golden bounty, ensuring that the moisture content remains at or below 15 percent. Winter wheat's harvest commences in the warmth of May, extending into the depths of July. Meanwhile, the harvest for spring wheat kicks off in late July, drawing to a close by the end of August.

In this cyclical journey from planting to harvest, wheat exemplifies resilience and adaptability, providing sustenance for humanity across generations. Its stages of life not only symbolize agricultural prowess but also serve as a testament to the intricate dance between nature and human ingenuity.
Wheat Life Stages: Planting, Growing, Harvesting

Wheat Harvesting

Combine harvesters collect the crop when the kernels have dried to a moisture level of 15 percent or less. Winter wheat harvesting typically kicks off in May and wraps up by late July, while spring wheat harvesting starts in late July and concludes by late August.

It is vital to harvest wheat promptly as it matures and begins to dry to moisture levels suitable for the market. Employing a moisture meter is highly advantageous for promptly assessing the crop's condition. Once wheat begins to dry in the field, repeated cycles of precipitation and drying can lead to a decrease in quality and test weight.

Wheat is typically harvested when its moisture content falls within the range of 13 to 15 percent. Harvesting at higher moisture levels is possible but necessitates swift drying to prevent spoilage and sprouting.

The harvesting process begins with cutting the standing crop, accomplished either in a single step through straight (direct) combining or in a series of steps involving windrowing (swathing), combining, and drying the grain to a safe moisture level for storage. Straight combining is the preferred method in most wheat production regions globally.

Failure to harvest crops results in diminishing quantitative and qualitative returns due to shatter losses and susceptibility to attacks by insects, mold, birds, and rodents. Therefore, completing the harvesting process as expeditiously as possible is crucial.

Freshly harvested wheat grain should be dried to a moisture content of 14 percent or less within 48 hours to prevent sprouting and spoilage. High-moisture wheat (>17%) can be efficiently dried using both high-speed and bin drying equipment.
Wheat Harvesting

Triticum aestivum

Wheat is one of the most important crops in the world. As the word population increases, the demand for wheat will continue to grow. Triticum aestivum is the number one food crop in the world based on acreage under cultivation and total production with production averages 216 million hectares.

It was first domesticated nearly 10,000 year ago in the fertile Crescent of the Tigris-Euphrates basin in Southwestern Asia.

Most of the wheat production is consumed as flour, with bread wheat (Triticum aestivum) accounting for approximately 80% of total consumption and durum wheat (Triticum durum) accounting for remainder. 

Triticum aestivum is the most important carbohydrate source for human consumption. It is 7 percent carbohydrate by weight with protein and indigestible fiber each comprising 10 to 15 percent.

Of the complex carbohydrate in Triticum aestivum, 75 percent is the chain of branching glucose units, amylopectin and 25 percent is the linear chain of glucose units, amylose.

The major grain protein of Triticum aestivum is gluten. It is and elastic form of protein that gives rise to unique viscoelastic properties of dough produce from bread flour suitable for a range of end products.
Triticum aestivum

Planting of winter wheat

Winter wheat is a cool season crop that is most productive when planted in autumn since cool weather from emergence to the early reproductive stage favors tillering and the subsequent development of large spikes.

It goes dormant during the winter and is harvested for grain during the following spring. Winter wheat requires ‘vernalization’ in order to complete its growth cycle.

Wheat is usually planted in September or early October when the soil is sufficiently moist to germinate the seed.

Wheat is grown from the same seeds or kernels that people eat. On large commercial farms, where wheat is grown for sale or export, farmers still sometimes save seed from previous years or they buy seed each year from seed companies.

Before the farmers can plant the seed, they add nutrients to the soil.

When they ready to plant, some farmers till the soil with a plow in order to break the soil up so it is soft enough for the seeds to take root.

After planting, freezing temperatures and a blanket of snow protect the seeds while they lay dormant awaiting the spring thaw.

Only after exposure to a period of low temperatures will the plants send up a stem and flower to form seeds in early summer.

About two-thirds of US wheat is winter wheat. Winter wheat can survive cold temperatures as low as -40 °F if protected by snow.
Planting of winter wheat

Wheat: species and variety

Cereals, including wheat are the major food crops for all humans and are the principal resources that have led to the emergence of human civilization as per today.

Wheat was and established food crop at the dawn of history. It probably originated from grasses native to the Middle East, but cultivation of bread wheat was common in Europe by the time of Greek and Roman Empire, and wheat was brought to America by the earliest explorer.

Wheat was the leading produced, averaging 620 MMT annually, representing almost one-third of all cereal production. It is grown in temperate zones around the world and on some part of every continent except Antarctica.

The principal species of wheat are:
*Triticum vulgare or bread wheat
*Triticum durum, which has extra hard kernels, used primarily for macaroni an related pasta products. 
*Triticum compactum or club wheat has a very soft kernel.

Most of the wheat varieties cultivated today are grouped together under the broad category of common or bread wheat which accounts for approximately 95% of world production.

There are numerous varieties and cultivars within each species. Wheat also classified in the United States according to whether it is hard or soft, white or red, and planted in winter or spring. It is also graded according to such criteria as test weight per bushel and content of damaged kernels, foreign materials, and wheat of other classes.

Wheat class and physical condition are the most important factors determining wheat milling potential and end-product quality.
Wheat: species and variety

Classification of Wheat

Wheat
Whole wheat, consisting of about 13% protein, can contribute considerably to the diet. The flour, made from the whole wheat, is higher in biological value than white flour (made from the endosperm only). Wheat is perhaps the most popular cereal grain for the production of bread, cakes and other pastries.

Wheat produces white flour. In addition, the unique properties of wheat protein alone can produce bread dough of the strength and elasticity required to produce low density bread and pastries of desirable texture and flavor. There are many varieties of wheat.
They may be classified as:
*hard red winter wheat,
*hard spring wheat,
*soft red winter wheat,
*white wheat,
*durum wheat.
Winter wheat are planted in the fall and harvested in the late spring and late summer. Spring wheat are planted in the spring and harvested in the late summer. Hard wheat are higher in protein content produce more elastic dough than the soft wheat. Therefore, hard wheats are used for bread, and soft wheats are used for cakes. Durum wheats are most used for alimentary pastes (spaghetti, macaroni, ets) and for the thickening of canned soup.
Wheat

Wheat Structure

Wheat Structure
Wheat structure is a single seeded fruit, 4 to 10 mm long, consisting of a germ and endosperm enclosed by an epidermis and a seed coat.

The fruit coat or pericaprs (45 to 50 um thick) surrounds the seed and adhere closely to the seed coat.

The wheat color, depending on the species and other factors is red a to white and is due to material present in the seed coat.

Wheat also is classified based on physical characterizes such as red, white soft, hard spring or winter.

The outer pericaprs is consist of the epidermis and hypodermis. The epidermis consists of a single layer of cells that from the outer surface of the kernel.

On the outer walls of the epidermal cells is the water impervious cuticle. Some epidermal cells at the apex of the kernel are modified to form hairs.

The hypodermis is composed of one to two layers of cells. The inner pericaprs is composed of intermediate cells and cross –cells inward from hypodermis.

Long and cylindrical tube cells constitute the inner epidermis of the pericaprs. In the crease, the seed coat joins the pigment strand, and together they form a complete coat about the endosperm and germ.

Three layers can be distinguished in the seed coat: a thick outer cuticle, a “color layer” that contains pigment, and a very thin inner cuticle.

The bran comprises all outer structures of the kernel inward to, and including the aleurone layer.

This layer is the outer layer of the endosperm, but is considered as part of the bran by millers.

The aleurone layer is usually one cell thick and almost completely surrounds the kernel over the starchy endosperm and germ.

The endosperm is composed of peripheral, prismatic and central cells that are different in shape, size and position within the kernel.

The endosperm cells are packed with starch granules, which lie embedded in a matrix that is largely protein.
Wheat Structure

Harvesting the Wheat

Harvesting the Wheat
In the United States, the wheat harvest will usually start in early May in southern Texas reach its peak in the hard red winter areas of the Southwest in early June, and end in October in the northern portions of the red spring wheat area.

Many years ago, the common method of harvesting grains was the binder, which may possibly still be used on some small farms.

Binders have been replaced nearly everywhere by combines, large and small.

These machines cut and thresh the crop and are usually self-propelled. Spring wheat may be cut windrowed or swathed before thrashing.

After combining, most spring and winter wheat is either stored in the farms for a time or promptly taken by truck to local elevators it is loaded on railway cars and carried to terminal markets.

Each year better highways and larger payloads increase the distances wheat can be hauled economically by truck.

Particularly in the corn belt area, soft red winter wheat is often stored in the farm, since smaller amounts are produced in the region and adequate storage facilities are not prohibitive in cost.

Both farm storage and hugh cooperative terminal storage facilities are common in the major wheat producing areas, where government programs in some years subsidize both types of storage.
Harvesting the Wheat

Wheat Classes: Hard Red Spring and Red Durum

Wheat Classes: Hard Red Spring and Red Durum

Hard Red Spring Wheat
Hard red spring wheat is grown principally in North and South Dakota, Montana, Minnesota and the Prairie Provinces of Canada.

It may be grown in other areas to replace winter wheat that has failed due to winter killing, drought or other causes. Hard red spring wheat is divided into three subclasses according to its content of dark, hard, and vitreous kernels.

These subclasses are dark northern spring wheat (75% or more), northern spring wheat (25 – 75%), and red spring wheat (less than 25%). Overall, hard red spring accounts for about 20% of the total wheat acreage in the United States. This class of wheat is used for bread and rolls.

Durum and Red Durum Wheats
Durum and durum wheats are grown in the north central states, especially North and South Dakota.

These classes of wheat account for approximately 5% of the wheat acreage of the United States. Durum wheat cannot be used to produce flour for bread making; rather it is milled to supply semolina for making macaroni, spaghetti, noodles, etc.

Durum wheat is divided into three subclasses,: hard amber durum wheat, which has 75% or more of hard, vitreous kernels of amber color; amber durum wheat, which has 60 - 75% of hard, vitreous kernels of amber color; and durum wheat, which has less than 60% of hard, vitreous kernels of amber color, the red durum class includes all varieties of red durum wheat and has no subclasses.
Wheat Classes: Hard Red Spring and Red Durum

Classification of Wheat

Classification of Wheat
Wheat belongs to the grass family, Gramineae, and the genus Triticum. The known species and varieties of the genus Triticum are said to number over 30,000. They can be assembles into three groups (races), which are traced from separate original ancestors and which differ in their number of chromosomes.

The classification suggests a possible explanation for differences in the flour from three wheat groups. Einkorn (T. monococcum) is used only as an animal feed. Emmer wheats are used for macaroni, spaghetti, and other pasta products, and not for breadmaking. Wheat from the spelt group is used in baked goods and other cereal products. The principle wheats of commerce are Triticum aestivum, Triticum compactum, both in the spelt group and Triticum durum, in the Emmer group.

In addition to their classification into groups based on chromosome number, wheats are classified as hard or soft referring to milling character and strong or weak.

The terms hard and soft wheat relate to the way the endosperm break during milling. In hard wheats, the endosperm tends to fracture along the lines of the cell boundaries, whereas in soft wheats the endosperm fractures in a random ways. Hard wheats yield coarse flour, consisting of regular-shaped particles, which is free flowing and easily sifted. In contrast, the flour from soft wheats is very fine and consists of irregularly-shaped particles, which tend to adhere together; such flour sifts with some difficulty.

Strength is a characteristic of wheat associated with the ability of its flour to produce bread of large loaf volume, good crumb texture and good keeping qualities. Strong wheats as a rule have a high protein content, whereas weak wheats have low protein contents. The flour from a weak wheat produces bread of small loaf volume, coarse crumb structure, and low protein content. Thus protein content is related to baking characteristics.
Classification of Wheat

Cereal in general

Cereal in general
Cereals are the dried seeds of the cultivated grasses, which belong to the family Gramineae. They include wheat, rye, barley, corn, oats, grain sorghum, and millet. Buckwheat, although not a true cereal, is usually included with them.

The cultivation and use of cereals antedates the recorded history of man. Excavations in early centers of civilization have indicated that one or another of the above cereals were known and used by the people of these cultures. The civilizations of Babylonia, Egypt, Greece, and Rome were founded on the production of wheat, barley, and the millets. The cultures of India, China, and Japan were dependent on the rice crop. The Inca, Maya, and Aztec cultures were based on the growing of corn (maize), which is apparently the only cereal indigenous to the Americas.

The cereals are, in general, the cheapest sources of food energy and can be grown anywhere in the world. They give high yields per acre, can be stored for relatively long periods of time, and can be transported cheaply.
Cereal in general

Wheat - Stages of Life

Wheat - Stages of Life
The stages of life of the wheat plant vary somewhat depending upon the variety being grown:

Planting:

Planting of winter wheat usually occurs in September or early October when the soil has sufficient moisture to germinate the seed. The germinated seed lies dormant during the winter. Spring wheat is planted as early in the spring as temperatures allow.

Growing:

The winter wheat plant resumes its growth in the spring. The head of the wheat plant, which contains the kernels, develops at the tip of the stem. The stem grows rapidly, pushing the head up and out of the top leaf sheath. After the head emerges, flowering occurs and the kernels begin to develop. After the kernels have developed fully and filled, the leaves and stem lose their green color and the kernels quickly dry.

Harvest:

Combines harvest the crop once the kernels have dried to 15 percent moisture or less. Harvesting of winter wheat starts in May and usually is completed by late July. Harvesting of spring wheat begins in late July and is completed by late August.
Wheat - Stages of Life