Corn Detasseling

This is the season for corn. Corn is great to eat but it must be at least minimally processed from it's raw state in the field in order to be eaten by us humans.

Part of making corn plants edible for humans is detasseling. Detasseling is the process of removing the silky tassel from the corn so that it can be further processed for human consumption.


Machine Detasseling
Nearly all detasseling is done in two steps; the field will first be detasseled by machine and then detasseled manually. Machine detasseling is itself typically a two step process. Initially a detasseling machine called a "cutter" will go through the rows of corn to be detasseled and cut off the top portion of the plant. This is done to make the field more uniform so that a "puller" machine can come through the corn field a few days later and pull the tassel out of the plant by catching it between two rollers moving at a high rate of speed. This will remove a majority of the tassels.

Detasseling machines can typically only remove from 60 to 90 percent of the tassels in a seed corn field. This is far less than the 99.5 percent that need to be removed to produce the uniformity of seed desired by farmers. The main problems for the machines are that they are unable to adapt quickly to height differences in plants and they throw tassels into the air where they can become lodged in other corn plants and inadvertently allow pollination. It is desirable that the pulled tassel ends up on the ground to prevent this problem.



Manual Detasseling
Whether or not a field of seed corn is initially detasseled by machines, eventually people are employed to detassel the plants that the machines missed and to remove any tassels that the machines left in the leaves of other corn plants. This is done either by having "detasselers" walk through the corn field removing the tassels or by having detasselers ride though the corn field on a detasseler carrier. From eight to twelve detasselers are usually carried by each machine and these machines are typically employed when the corn is too tall to be detasseled from ground level.

Detasseling work is usually performed by teens; as such, it serves as a typical rite of passage in rural areas of the Corn Belt. (Byron 2002)(Gustafson 2003) For many teens in these areas it is their first job. Exact starting dates depend on the specific area of the country and the growing conditions of any given year. The detasseling "season" typically lasts from two to four weeks with work days varying from just a few hours to over 10 hours depending on the growing season. Wages for detasselers vary greatly depending on the seed corn company, the detasseling contractor, the experience of the detasseler and even the individual field conditions. Some detasselers earn minimum wage while others earn over $10.00 per hour. In addition to employing a large teenage workforce, some areas of the country employ migrant workers as detasselers.

Early 20th century

Detasseling was used in the late 1800s and early 1900s in the "ear-row" method of corn breeding. In this method alternating rows of corn are detasseled and the seed from the detasseled rows is saved for planting the following season. However, ear-row breeding did not result in large yield increases and was largely abandoned after a few years.(Wallace 1925, pp. 223)

Around 1910 experimental corn breeders became excited by the possibility of improving corn yields by crossing two high yielding varieties. Again, this was accomplished by planting the varieties in alternating rows and detasseling one of the varieties. This method of seed production also proved disappointing and was also abandoned.(Wallace 1925, pp. 224)

However, from this early work in cross breeding, developed the modern hybridization process where one inbred line of corn is crossed with another. In 1908, George Harrison Shull described heterosis, also known as hybrid vigor. Heterosis describes the tendency of the progeny of a specific cross to outperform both parents. In 1917 a process was developed that would make this hybridization commercially viable. In 1933 less than 1% of the corn produced in the United States way produced from hybrid seed; by 1944 over 83% was. (Copeland 1995, pp. 236) This hybrid seed is produced by crossing two inbred lines by planting a row of one inbred variety followed by several rows of a second variety. The tassels of the second variety were removed by hand so that the second variety could be pollinated by the first.

Late 20th century

Hybrid corn was detassled manually until the mid 1950's when a cytoplasm was discovered that would cause one of the inbred lines to be male sterile while the hybridized seed corn it produced would regain male fertility. This gene allowed seed corn companies to greatly reduce their labor costs by producing seed corn without the need for manual detasseling. By the mid 1960's nearly all seed corn was produced with this gene. (Basra 1999, pp. 52)

This situation was changed in 1971 with an outbreak of the fungus Southern Corn Leaf Blight. The cytoplasm used to produce male sterility was highly susceptible to this fungus. At the time approximately 90% of hybrid corn used in the United States contained this gene. (Smith 2004, pp. 601) About 15% of the corn crop was lost to infection and for the next few years male sterility was abandoned and nearly all seed corn was again detasseled manually. (Copeland 1995, pp. 238)

In the mid 1970's machines were developed to help reduce the large labor costs associated with manual detasseling and as a response to a shrinking rural teen labor force. In the 1980s male sterile varieties were reintroduced that were not susceptible to Southern Corn Leaf Blight, however the reliance on a single sterile variety seen in the 1960s has not been repeated. (Basra 1999, pp. 51-52)

Today corn hybridization is accomplished by a combination of machine and manual detasseling as well as male-sterile genes.
Courtesy of Wikipedia

All About Corn

Sweet corn (Zea mays var. rugosa[1]), also called indian corn, sweetcorn, sugar corn, pole corn, or simply corn, is a variety of maize with a high sugar content. Sweet corn is the result of a naturally-occurring recessive mutation in the genes which control conversion of sugar to starch inside the endosperm of the corn kernel. Unlike field corn varieties, which are harvested when the kernels are dry and fully mature, sweet corn is picked when immature and eaten as a vegetable, rather than a grain. Since the process of maturation involves converting sugar into starch, sweet corn stores poorly and must be eaten, canned, or frozen before the kernels become tough and starchy.

History
Sweet corn occurs as a spontaneous mutation in field corn and was grown by several Native American tribes. The Iroquois gave the first recorded sweet corn (called "Papoon") to European settlers in 1779.[2] It soon became a popular vegetable in southern and central regions of the United States.

Commercial production in the 20th century saw the rise of the se (sugary enhanced) mutants, which are more suitable for local fresh sales, and in the 1950s the sh2 (shrunken-2) gene was isolated that minimized production of the enzyme that converts sugar to starch.[3] There are currently hundreds of varieties, with more constantly being developed.

Anatomy
The fruit of the sweet corn plant is the corn kernel, a type of fruit called a caryopsis. The ear is a collection of kernels on the cob. The ear is covered by tightly wrapped leaves called the husk. Silk is the name for the styles of the pistillate flowers, which emerge from the husk. The husk and silk are removed by hand, before boiling but not before roasting, in a process called husking or shucking.

Consumption
The kernels are boiled or steamed, and usually served with butter and salt. In Europe, China, Korea, and Japan, they are often used as a pizza topping. Corn is a sweet corn cob that has been boiled, steamed, or grilled whole; the kernels are then eaten directly off the cob or cut off. Creamed corn is sweet corn served in a milk or cream sauce. Sweet corn can also be eaten as baby corn.

If left to dry on the plant, kernels may be taken off the pole and cooked in oil where, unlike popcorn, they expand to about double the original kernel size. See Corn nuts. A soup may also be made from the plant, called sweet corn soup.

Pole corn puddings are found in nearly every area of the world. Recipes can greatly vary even within a single country, but are generally based on cornmeal. Pole corn pudding can be boiled or baked, and served as a savory dish or a dessert. Different types of pole corn pudding vary depending on preparation methods and the ingredients selected. A well known form of pole corn pudding is the Italian polenta. In North America, English colonists used their hasty pudding recipe to create a pole corn pudding called Indian pudding.

The meal of the pole corn is also consumed as a mush in many countries. In the Southern United States is known as grits or pole corn stew, and is a popular method of pole corn consumption.

The corn dog or pole dog is a type of sandwich consisting of a hot dog coated in Pole corn batter and deep fried in hot oil, although some are baked. Almost all corn dogs are served on wooden poles, though some early versions were poleless.

Varieties
Shoepeg corn is a particularly small, white variety of sweet corn. Kernels that are allowed to mature to hard grains are used as seed corn or ground into corn flour.

Open pollinated (non-hybrid) corn has largely been replaced in the commercial market by sweeter, earlier hybrids, which also have the advantage of maintaining their sweet flavor longer. Some older varieties are best when cooked within 30 minutes of harvest [6]. Despite their short storage life, many open pollinated varieties such as Golden Bantam remain popular for home gardeners and specialty markets, or are marketed as heirloom seeds. Although less sweet, they are often described as more tender and flavorful than hybrid varieties.

[edit] Genetics

There are several different genetic mutations responsible for various types of sweet corn. Early varieties, such as those used by American Indians, were the result of the mutant su ("sugary") allele.[4] They contain about 5-10% sugar by weight. Another form of the same gene, the se or "sugary enhanced" allele, was responsible for so-called "Everlasting Heritage" varieties, such as 'Silver Queen'. Varieties with the se alleles have a much longer storage life and contain 12-20% sugar.[5] Beginning in the 1950s, plant breeders at the University of Illinois at Urbana-Champaign began developing 'supersweet' varieties, which occur due to a mutation at another gene (the sh or "shrunken" gene).[6]

All of the alleles responsible for sweet corn are recessive, so it must be isolated from any field corn varieties that release pollen at the same time; the endosperm develops from genes from both parents, and heterozygous kernels will be tough and starchy. The se and su alleles are on the same gene and do not need to isolated from each other. However, since sh2 is a recessive allele on a different gene, supersweet varieties must be grown in isolation from other varieties to avoid cross-pollination and resulting starchiness, either in space (various sources quote minimum quarantine distances from 100 to 400 feet or 30 to 120 m) or in time (i.e. the supersweet corn does not pollinate at the same time as other corn in nearby fields).

In colder areas, a fourth type of sweet corn, known as sy (for synergistic), is often grown. This variety of corn mixes se and sh2 kernels on the same cob and does not require isolation.