RSSSweet Corn That Home Garden Favorite For Good Nutrition
Sweet corn is a common item in most American home gardens. It provides a delightful addition to everyday meals, and in season the roasting ears are enjoyed for picnics and cookouts. Since the days of the Pilgrims, corn-on-the-cob has been a popular American favorite. Sweet corn¿either fresh, frozen or canned¿may be served as a separate dish or used in succotash (an American Indian dish), custards, puddings, fritters, souffles, and stuffed peppers, or added to soups and chowders. Sweet corn may also be used in relishes and mixed pickles.
Most gardeners will regard sweet corn as an essential item in their garden and take great pride in the good nutrition and eating pleasure it affords.
Corn (Zea mays) is a member of the grass family, which includes other cereal crops such as wheat, oats, barley, sorghum, and rice. Corn is conveniently divided into six types based on its use and kernel characteristics. These are dent corn, sweet corn, popcorn, flint corn, flour corn and pod corn. They are all of the same species but differ genetically. Dent corn, sweet corn, and popcorn are the most commonly grown for their food and feed value throughout the world.
Sweet corn is believed by most authorities to have originated in North America as a mutation from field corn. The first references to sweet corn date from 1779; an 8-rowed, red-cob type called Susquehanna, or Papoon, was introduced that year near Plymouth, Mass. In Thomas Jefferson’s Garden Book (1810) "shriveled corn" is mentioned, which is obviously sweet corn.
By 1828 "sugar corn" was listed in New England seed catalogs. Also, evidence indicates sweet corn was being grown by the American Indians of the upper Missouri by 1833. Another early reference to sweet corn appeared in the Travel Letters (1821) of Timothy Dwight as being the most delicious vegetable of any known in this country.
Sweet corn as a specific crop must have come into existence at least by 1820 and reached sufficient popularity by 1828 to be in a seed catalog. The subsequent history of sweet corn is one of variety development. By 1900 there were no less than 63 varieties, and the first F1 hybrid was introduced about 1924. Today, there are well over 200 varieties and hybrids available to sweet corn growers and gardeners.
Sweet corn differs from the other types of corn primarily by its ability to produce and retain greater quantities of sugar in the kernels. This characteristic is conditioned by a single recessive gene called sugary-1, symbolized su1. Other less pronounced differences are its tender kernels at edible maturity, refined flavors, a tendency to produce suckers at the base of the plant, and wrinkled seeds when dried. Dent corn is considered the "normal" type with all the other types being genetic variation (mutations) of it. Popcorn, for example, has very hard starch in the kernels that expands explosively when heated, thus producing the fluffy white popcorn kernel.
In recent years a new kind of sweet corn has come into use that is sweeter than the standard sweet corn. Its sweetness is not conditioned by the sugary-1 gene but by a similar genetic factor designated shrunken-2 (sh2). This gene conditions an even higher level in sugar in the kernels, giving them a sweeter taste and prolonging the edible state by three or four days.
The different types of corn should never be planted together at the same time. Pollen from dent corn or popcorn will contaminate sweet corn, causing the kernels to be starchy and not sweet. Likewise, the standard sweet varieties should not be inter-planted at the same time with the extra sweet (shrunken-2) varieties, as the pollen from one will contaminate the other¿destroying the quality of both. If both types are to be planted they should be separated by at least 400 yards distance, or one planted about four weeks after the other so they are not pollinating at the same time.
Sweet corn is essentially a warm-weather crop. It is easily killed by frost and may be seriously injured by prolonged temperatures several degrees above freezing. Germination and emergence of the seedlings are delayed and may be prevented by soil temperatures below 50° F. Sweet corn does best in areas having mean temperatures of 65° to 75° during the required 65- to 100-day growing season. In the Northeast and North Central States this corresponds to the months June, July and August. In central and south Florida, on the other hand, sweet corn is planted fall, winter and spring. Generally, sweet corn can be grown successfully in the proper season from Mexico to Canada and in many other parts of the world.
Sweet corn will grow satisfactorily on a wide range of soil types as long as they are friable and well drained. However, a deep, loamy, naturally rich soil is preferred. Soil should be only moderately acid (pH 5.8 to 6.8). If the pH is lower than 5.8, lime should be applied. Have soil tests made to determine the proper kind and amount of lime and fertilizer to apply. Consult your local Agricultural Extension Agent since most States have laboratories that provide a soil testing service.
Available plant nutrients are especially important early in plant growth. If the plants become nutrient-deficient and stunted, they never fully recover and the yield will be reduced. Commercial fertilizers are recommended for sweet corn on just about all soils throughout the country. Fertilizer recommendations for sweet corn vary for different sections of the country and from one soil type to another. Again, depend on soil testing for specific recommendations.
On light sandy soils of the Atlantic and Gulf Coastal Plains, broadcast 20 pounds of 10-10-10 fertilizer per 1,000 square feet of area before planting. Then apply a side dress of nitrogen when the corn is in the 6 to 8 leaf stage at the rate of about a half pound of actual nitrogen (N) per 100 feet of row (note that Ammonium Nitrate contains 33 percent actual N and Sodium Nitrate contains 16 percent).
On soil of average fertility in the Northeast, apply 15 to 18 pounds of 5-10-5 per 1,000 square feet of area prior to planting and about 3 pounds of the same fertilizer banded per 100 feet of row at the time of planting.
In the more fertile valleys of the West and Pacific Northwest and on the rich soils of the Midwest corn belt, apply in bands 3 to 5 pounds of 5-10-5 per 100 feet of row at the time of planting.
The broadcast applications are usually worked into the soil before planting. The band applications should be made when the seedbed is prepared, about 3 inches to the sides of the row of seed and 1 to 2 inches deeper than the seed is planted. The above rates are based on rows spaced 3 feet apart.
Sweet corn requires a continuous and adequate moisture supply for satisfactory growth and yield. In non-irrigated areas of the United States, sweet corn is grown with reasonable success where the rainfall from April through September is 20 inches or more and fairly well distributed. Unless the soil can retain a large supply of water, sweet corn will suffer from lack of moisture if rainless periods last more than 2 weeks during the growing season.
In the South and Southwest, after the tassels show, the plants need rain or irrigation every week. For these areas, and where soil moisture is likely to be depleted, it is advisable to provide some supplemental irrigation. Furrow irrigation is satisfactory in most soils where runoff can be controlled.
Sweet corn varieties differ in the way their growth is affected by day length. Early maturing varieties developed for the North are not recommended for the South. They are adapted to the long, cool summer days in the North and do not make satisfactory growth in the deep South. Conversely the southern varieties are not adapted to the North. When planted in the North they may not silk and tassel until they reach 8 to 12 feet in height, and it is too late for them to produce edible corn before frost. Therefore, specific varieties are recommended for different sections of the country.
F1 hybrids have largely replaced the open-pollinated varieties. As with all hybrid plants, new seed must be obtained for each crop. Seed saved from the hybrid plants will not reproduce true to type and will not retain the hybrid vigor of the parent plants. Several public research agencies and private companies breed and introduce new varieties of sweet corn. As a result, a large number of excellent hybrids are available for gardeners. Some hybrids will be available for only a few years, being replaced by better ones.
Sweet corn variety trials are conducted each year by many State agricultural experiment stations, and lists of recommended varieties are published based on these trials. Contact your State agricultural extension service for a list of varieties recommended specifically for your area.
Sweet corn requires plenty of space and is adapted only to larger gardens exposed to full sunlight. It does best planted in rows 30 to 36 inches apart with single plants spaced 12 to 16 inches apart in the row. Overcrowding the corn will reduce the ear yield drastically. Planting four or more short rows is better than one long row to insure complete pollination. If the prevailing wind is across the row, pollen will be carried away from the silks and result in poorly filled ears.
To conserve space in the garden, corn may be planted next to vine crops, such as cucumber and cantaloupe. As the vines grow, they will grow between the corn plants.
Proper seedbed preparation is important for sweet corn in the garden since herbicides are generally not used. A clean freshly worked seedbed enables the seedling to emerge rapidly and get off to a good start ahead of grass and weeds. Seed should be planted to a depth of about 1 inch in moist, heavy soils and 1 to 2 inches in light, sandy soils, depending on the moisture conditions at planting time.
It is generally a good idea to plant at approximately twice the desired stand and thin to single stalks at the desired spacing after the seedlings have become well established. This will allow for any reduction in seed germination and for loss of a few emerging seedlings to insects, birds and other garden pests. About a quarter pound of seed is sufficient for each 100 feet of row.
Successive plantings are recommended in order to provide a steady supply of fresh corn throughout the practical harvest season. Also, an early, followed by a full season variety, may be planted at the same time to give a prolonged harvest period.
Once the desired stand has been established, the area should be kept free of weeds by cultivation and hoeing.
Diseases: Diseases are generally not a serious threat to clean, well nourished sweet corn plantings. Those that do occur most frequently are seedling root rot, Stewart’s bacterial wilt, and common corn smut.
Root rot is caused by rot-producing fungi in the soil. It is often associated with a damp, cold soil, and may be evident as a slight stunting and irregular plant growth. Seed treatment with a fungicide provides good protection for the seedling during its early growth. Most sweet corn seeds packaged and sold commercially today have been treated with a fungicide. Use treated seeds whenever practical.
Stewart’s wilt may appear at any stage of growth, but is most noticeable when plants attain considerable size. It produces yellow to brown streaks up to an inch wide on the leaves, and may extend the entire length of the leaf. Brown discoloration and sunken cavities form in the stalk near the soil line. Plants that become infected early may wilt and die. Those infected later may be only stunted and have streaked leaves.
The disease tends to be more prevalent after mild winters and is known to be spread by corn flea beetle. There are no sprays or seed treatments effective for controlling this disease.
Where wilt is suspected of becoming a problem, resistant varieties should be planted. Most varieties developed in recent years are resistant to the disease, particularly among the full season maturity group.
Common smut is characterized by the presence of large, fleshy galls on the stalks, leaves, tassel and ears. At first the galls are silvery white and spongy. Later, they turn brown or black, rupture and release large masses of powdery black spores. Smut galls are unsightly and render the affected ears inedible. Smut is promoted by injuries to the plant during cultivation, by insects, or hail. Again, there are no chemical treatments to control the disease.
The best means of control is to avoid injuring the plants, avoid areas where smut occurred the previous year, and remove and destroy smut galls before they break open. This last step will prevent the spores from being released to infect later plantings.
Insects: Many species of insects are known to attack and damage sweet corn at all stages of its growth. Those that attack the plants early are more apt to cause serious damage, and they need to be dealt with promptly. These include the southern corn rootworm, cutworms, white grubs, wireworms and flea beetles. You can get some protection against the rootworms, wireworms, and grubs by using seed treated with a combination fungicide-insecticide. Cutworms and flea beetles may require an application of insecticide for control.
Insects attacking sweet corn later in its growth are corn borers, army-worms, aphids and the corn earworm. Several insecticides are available to control them. Recommendations for specific compounds to use and rates of application can usually be obtained from a reputable garden supply center.
Once the sweet corn becomes established and attains most of its plant growth it can withstand a surprising amount of insect feeding without drastic loss of yield. Earworms that begin feeding on the silks and burrow into the ear tips are difficult to control. Unless the infestation is extremely high and damaging, most gardeners choose to ignore the worm at the tip of the ear, merely clipping off the ear tip and any damaged kernels when the corn is husked.
Most State agricultural experiment stations publish current recommendations for controlling insects on sweet corn. These bulletins and circulars can be obtained by writing to your State Agricultural Extension Service.
Sweet corn should be harvested when the kernels are in the milk stage. At this stage the silks are brown and dry beyond the end of the husks and the ear has enlarged enough to fill the husks tightly to the tip. The kernels are about as large as they will become, but they are still soft, tender and filled with an opaque milky juice.
With some experience the optimum maturity for harvest can be recognized by sight and feel. The husks should never be disturbed to peek at the corn as this will permit insects and birds to invade the ear.
Another way to estimate harvest time is to note the date of silk emergence on the earliest plants in a row, then harvest those ears 17 to 24 days later. The number of days from silk emergence to prime harvest will vary according to weather conditions. If days and nights are exceptionally warm, prime maturity may be reached 17 or 18 days after silking. If cooler weather prevails during this period, it may require 22 to 24 days. After picking a few ears, you usually can make an accurate determination about harvesting the remainder of the corn at its prime maturity.
Sweet corn passes through its prime maturity very quickly. With uniform hybrid varieties the harvest of a single planting will last only about 4 to 5 days. If harvest is delayed the kernels become tough, starchy and lose their sweet flavor.
Sweet corn also loses its quality rapidly after it has been picked from the plant. For best quality, the corn should be picked early in the morning and refrigerated immediately. The sooner it is prepared for serving the better, but it can be held in a refrigerator (35 to 40° F) for 2 to 3 days with only a moderate reduction in eating quality.
To harvest corn, break the ear shank as close to the ear as practicable without breaking the main stalk or tearing the entire shank from the stalk. Grasp the car with one hand near its base and bend it sharply downward or to one side with a rotary motion of the wrist. The inexperienced may need to use both hands; hold the shank with one hand and use the other to snap the ear off. With practice and a strong grip, the ears of most varieties can be snapped off with one hand.
Many of the modern hybrids under optimum fertility and growing conditions will produce two nice ears per plant. The top ear will be the dominant one, and it will reach prime maturity a day or so ahead of the second ear. Under such conditions a 100-foot row should yield 100 to 120 nice ears.
Most gardeners will regard sweet corn as an essential item in their garden and take great pride in the good nutrition and eating pleasure it affords.
Corn (Zea mays) is a member of the grass family, which includes other cereal crops such as wheat, oats, barley, sorghum, and rice. Corn is conveniently divided into six types based on its use and kernel characteristics. These are dent corn, sweet corn, popcorn, flint corn, flour corn and pod corn. They are all of the same species but differ genetically. Dent corn, sweet corn, and popcorn are the most commonly grown for their food and feed value throughout the world.
Sweet corn is believed by most authorities to have originated in North America as a mutation from field corn. The first references to sweet corn date from 1779; an 8-rowed, red-cob type called Susquehanna, or Papoon, was introduced that year near Plymouth, Mass. In Thomas Jefferson’s Garden Book (1810) "shriveled corn" is mentioned, which is obviously sweet corn.
By 1828 "sugar corn" was listed in New England seed catalogs. Also, evidence indicates sweet corn was being grown by the American Indians of the upper Missouri by 1833. Another early reference to sweet corn appeared in the Travel Letters (1821) of Timothy Dwight as being the most delicious vegetable of any known in this country.
Sweet corn as a specific crop must have come into existence at least by 1820 and reached sufficient popularity by 1828 to be in a seed catalog. The subsequent history of sweet corn is one of variety development. By 1900 there were no less than 63 varieties, and the first F1 hybrid was introduced about 1924. Today, there are well over 200 varieties and hybrids available to sweet corn growers and gardeners.
Sweet corn differs from the other types of corn primarily by its ability to produce and retain greater quantities of sugar in the kernels. This characteristic is conditioned by a single recessive gene called sugary-1, symbolized su1. Other less pronounced differences are its tender kernels at edible maturity, refined flavors, a tendency to produce suckers at the base of the plant, and wrinkled seeds when dried. Dent corn is considered the "normal" type with all the other types being genetic variation (mutations) of it. Popcorn, for example, has very hard starch in the kernels that expands explosively when heated, thus producing the fluffy white popcorn kernel.
In recent years a new kind of sweet corn has come into use that is sweeter than the standard sweet corn. Its sweetness is not conditioned by the sugary-1 gene but by a similar genetic factor designated shrunken-2 (sh2). This gene conditions an even higher level in sugar in the kernels, giving them a sweeter taste and prolonging the edible state by three or four days.
The different types of corn should never be planted together at the same time. Pollen from dent corn or popcorn will contaminate sweet corn, causing the kernels to be starchy and not sweet. Likewise, the standard sweet varieties should not be inter-planted at the same time with the extra sweet (shrunken-2) varieties, as the pollen from one will contaminate the other¿destroying the quality of both. If both types are to be planted they should be separated by at least 400 yards distance, or one planted about four weeks after the other so they are not pollinating at the same time.
Climatic Needs
Sweet corn will grow satisfactorily on a wide range of soil types as long as they are friable and well drained. However, a deep, loamy, naturally rich soil is preferred. Soil should be only moderately acid (pH 5.8 to 6.8). If the pH is lower than 5.8, lime should be applied. Have soil tests made to determine the proper kind and amount of lime and fertilizer to apply. Consult your local Agricultural Extension Agent since most States have laboratories that provide a soil testing service.
Available plant nutrients are especially important early in plant growth. If the plants become nutrient-deficient and stunted, they never fully recover and the yield will be reduced. Commercial fertilizers are recommended for sweet corn on just about all soils throughout the country. Fertilizer recommendations for sweet corn vary for different sections of the country and from one soil type to another. Again, depend on soil testing for specific recommendations.
Some general fertilizer recommendations for typical soils follow:
On soil of average fertility in the Northeast, apply 15 to 18 pounds of 5-10-5 per 1,000 square feet of area prior to planting and about 3 pounds of the same fertilizer banded per 100 feet of row at the time of planting.
In the more fertile valleys of the West and Pacific Northwest and on the rich soils of the Midwest corn belt, apply in bands 3 to 5 pounds of 5-10-5 per 100 feet of row at the time of planting.
The broadcast applications are usually worked into the soil before planting. The band applications should be made when the seedbed is prepared, about 3 inches to the sides of the row of seed and 1 to 2 inches deeper than the seed is planted. The above rates are based on rows spaced 3 feet apart.
Moisture Needs
In the South and Southwest, after the tassels show, the plants need rain or irrigation every week. For these areas, and where soil moisture is likely to be depleted, it is advisable to provide some supplemental irrigation. Furrow irrigation is satisfactory in most soils where runoff can be controlled.
Sweet corn varieties differ in the way their growth is affected by day length. Early maturing varieties developed for the North are not recommended for the South. They are adapted to the long, cool summer days in the North and do not make satisfactory growth in the deep South. Conversely the southern varieties are not adapted to the North. When planted in the North they may not silk and tassel until they reach 8 to 12 feet in height, and it is too late for them to produce edible corn before frost. Therefore, specific varieties are recommended for different sections of the country.
Hybrids
Sweet corn variety trials are conducted each year by many State agricultural experiment stations, and lists of recommended varieties are published based on these trials. Contact your State agricultural extension service for a list of varieties recommended specifically for your area.
Sweet corn requires plenty of space and is adapted only to larger gardens exposed to full sunlight. It does best planted in rows 30 to 36 inches apart with single plants spaced 12 to 16 inches apart in the row. Overcrowding the corn will reduce the ear yield drastically. Planting four or more short rows is better than one long row to insure complete pollination. If the prevailing wind is across the row, pollen will be carried away from the silks and result in poorly filled ears.
To conserve space in the garden, corn may be planted next to vine crops, such as cucumber and cantaloupe. As the vines grow, they will grow between the corn plants.
Proper seedbed preparation is important for sweet corn in the garden since herbicides are generally not used. A clean freshly worked seedbed enables the seedling to emerge rapidly and get off to a good start ahead of grass and weeds. Seed should be planted to a depth of about 1 inch in moist, heavy soils and 1 to 2 inches in light, sandy soils, depending on the moisture conditions at planting time.
It is generally a good idea to plant at approximately twice the desired stand and thin to single stalks at the desired spacing after the seedlings have become well established. This will allow for any reduction in seed germination and for loss of a few emerging seedlings to insects, birds and other garden pests. About a quarter pound of seed is sufficient for each 100 feet of row.
Successive plantings are recommended in order to provide a steady supply of fresh corn throughout the practical harvest season. Also, an early, followed by a full season variety, may be planted at the same time to give a prolonged harvest period.
Once the desired stand has been established, the area should be kept free of weeds by cultivation and hoeing.
Diseases: Diseases are generally not a serious threat to clean, well nourished sweet corn plantings. Those that do occur most frequently are seedling root rot, Stewart’s bacterial wilt, and common corn smut.
Root rot is caused by rot-producing fungi in the soil. It is often associated with a damp, cold soil, and may be evident as a slight stunting and irregular plant growth. Seed treatment with a fungicide provides good protection for the seedling during its early growth. Most sweet corn seeds packaged and sold commercially today have been treated with a fungicide. Use treated seeds whenever practical.
Stewart’s wilt may appear at any stage of growth, but is most noticeable when plants attain considerable size. It produces yellow to brown streaks up to an inch wide on the leaves, and may extend the entire length of the leaf. Brown discoloration and sunken cavities form in the stalk near the soil line. Plants that become infected early may wilt and die. Those infected later may be only stunted and have streaked leaves.
The disease tends to be more prevalent after mild winters and is known to be spread by corn flea beetle. There are no sprays or seed treatments effective for controlling this disease.
Where wilt is suspected of becoming a problem, resistant varieties should be planted. Most varieties developed in recent years are resistant to the disease, particularly among the full season maturity group.
Common smut is characterized by the presence of large, fleshy galls on the stalks, leaves, tassel and ears. At first the galls are silvery white and spongy. Later, they turn brown or black, rupture and release large masses of powdery black spores. Smut galls are unsightly and render the affected ears inedible. Smut is promoted by injuries to the plant during cultivation, by insects, or hail. Again, there are no chemical treatments to control the disease.
The best means of control is to avoid injuring the plants, avoid areas where smut occurred the previous year, and remove and destroy smut galls before they break open. This last step will prevent the spores from being released to infect later plantings.
Insects: Many species of insects are known to attack and damage sweet corn at all stages of its growth. Those that attack the plants early are more apt to cause serious damage, and they need to be dealt with promptly. These include the southern corn rootworm, cutworms, white grubs, wireworms and flea beetles. You can get some protection against the rootworms, wireworms, and grubs by using seed treated with a combination fungicide-insecticide. Cutworms and flea beetles may require an application of insecticide for control.
Insects attacking sweet corn later in its growth are corn borers, army-worms, aphids and the corn earworm. Several insecticides are available to control them. Recommendations for specific compounds to use and rates of application can usually be obtained from a reputable garden supply center.
Once the sweet corn becomes established and attains most of its plant growth it can withstand a surprising amount of insect feeding without drastic loss of yield. Earworms that begin feeding on the silks and burrow into the ear tips are difficult to control. Unless the infestation is extremely high and damaging, most gardeners choose to ignore the worm at the tip of the ear, merely clipping off the ear tip and any damaged kernels when the corn is husked.
Most State agricultural experiment stations publish current recommendations for controlling insects on sweet corn. These bulletins and circulars can be obtained by writing to your State Agricultural Extension Service.
Harvesting
With some experience the optimum maturity for harvest can be recognized by sight and feel. The husks should never be disturbed to peek at the corn as this will permit insects and birds to invade the ear.
Another way to estimate harvest time is to note the date of silk emergence on the earliest plants in a row, then harvest those ears 17 to 24 days later. The number of days from silk emergence to prime harvest will vary according to weather conditions. If days and nights are exceptionally warm, prime maturity may be reached 17 or 18 days after silking. If cooler weather prevails during this period, it may require 22 to 24 days. After picking a few ears, you usually can make an accurate determination about harvesting the remainder of the corn at its prime maturity.
Sweet corn passes through its prime maturity very quickly. With uniform hybrid varieties the harvest of a single planting will last only about 4 to 5 days. If harvest is delayed the kernels become tough, starchy and lose their sweet flavor.
Sweet corn also loses its quality rapidly after it has been picked from the plant. For best quality, the corn should be picked early in the morning and refrigerated immediately. The sooner it is prepared for serving the better, but it can be held in a refrigerator (35 to 40° F) for 2 to 3 days with only a moderate reduction in eating quality.
To harvest corn, break the ear shank as close to the ear as practicable without breaking the main stalk or tearing the entire shank from the stalk. Grasp the car with one hand near its base and bend it sharply downward or to one side with a rotary motion of the wrist. The inexperienced may need to use both hands; hold the shank with one hand and use the other to snap the ear off. With practice and a strong grip, the ears of most varieties can be snapped off with one hand.
Many of the modern hybrids under optimum fertility and growing conditions will produce two nice ears per plant. The top ear will be the dominant one, and it will reach prime maturity a day or so ahead of the second ear. Under such conditions a 100-foot row should yield 100 to 120 nice ears.
: Sweet Corn That Home Garden Favorite For Good Nutrition - Sweet corn is a common item in most American home gardens. It provides a delightful addition to everyday meals, and in season the roasting
