This vegetable of American origin, developed from common field corn or maize, is of great commercial importance. It is very generally grown throughout the country and our markets are well supplied from July until cold weather. It is also grown extensively for canning, immense areas being planted annually in some sections for this purpose. With the improvement of varieties consumption is increasing.
There is a long list of early varieties regarded as desirable by vegetable growers.
Adams Early is not a true sweet corn, but its quality is much superior to that of field corn. It is valued because of its hardiness and earliness. It may be planted at least 10 days earlier than the true sweet corn.
White Cob Cory is very prolific. It is a favorite with many growers.
Fordhook is very early and is planted extensively.
Golden Bantam is generally recognized as the most superior variety in cultivation in regard to quality. It is not quite as early as the better-known early varieties, but may be had throughout the season by planting in succession. It is especially desirable for the home garden, and is rapidly gaining popularity for commercial purposes. There is usually some objection to the color, which is creamy yellow when the ears are ready for market, but the consumer seldom objects to the color after the corn has once been sampled. Other popular early varieties are Stabler, Crosby, Sheffield, Red Cob Cory and Minnesota.
Some of the best early varieties are often planted in succession to meet the demands of midsummer. When this is not desired the following second early varieties may be selected: Cosmopolitan, Sweet Orange (regarded as equal in quality to Golden Bantam) and Kendal Giant.
Country Gentleman and Stow-ell Evergreen are the most popular and extensively grown late varieties and are used largely by the canning factories. Regarding their merits, the Maryland Station (Md. Sta. Bul. 120, p. 47) makes the following statement: "Stowell Evergreen gives a larger yield an acre and packs more cases a ton than most varieties. It usually commands about $2 less a ton in price than the Country Gentleman. The latter variety gives a more desirable canned product and brings more money a case".
The results, whether the corn is grown for the cannery or for market, depend largely upon the quality of seed planted. Some growers maintain special breeding plats. The reader should refer to Bulletin 183 of the Maine Experiment Station, and the circular prepared by Director Charles D. Woods, entitled "Practical Suggestions Regarding the Growing of Sweet Corn for Packing and for Seed." It is just as important for sweet corn growers to use high-grade, well-bred seed as for farmers to plant the best field corn. Experiments made at the Maryland Station (Md. Sta. Bul. 120) indicate that northern grown seed possesses no value over southern grown, but that acclimatization is essential to the best results.
With the use of paper pots it is thoroughly practical to start part of the crop under glass, and transplant to the open ground after danger of frost. The roots should not be disturbed, so that pots must be employed to make this method successful. Starting sweet corn under glass is not generally practiced, but if there is reasonable assurance of good prices the increased earliness will more than make up for the extra trouble and expense of starting the plants. It is doubtful whether the corn should be planted more than three weeks in advance of field planting. Any good compost may be used to fill the pots. About six grains should be planted in a 3-inch paper or earthen pot, and thinned to three or four plants, which later are set in the open ground. Cold frames may be used to start the plants, if a greenhouse is not available.
Soil well adapted to common field corn will produce good sweet corn, which thrives on heavy, clover sods plowed in the fall or early in the spring. Rotten or fresh manures of all kinds may be used to advantage. Eight or 10 tons of stable manure an acre applied on clover sod provides the most favorable conditions. Commercial fertilizers are also used in large amounts for the sweet corn crop, the applications varying from a few hundred pounds to a ton an acre. It is not uncommon for expert growers operating near good local markets to apply 1,500 pounds or a ton an acre, although 1,000 pounds is considered liberal treatment. The mixtures used for this crop generally contain 3 to 5 per cent of nitrogen and 7 to 10 per cent each of the mineral elements.
Sod land is invariably the best for sweet corn. Other fertile soils, cultivated the preceding year, may be used with success. Fall plowing of sods in northern sections is often desirable for the very early varieties. If plowing be deferred until spring, there should be no delay. The harrow should be used promptly after plowing and often enough to conserve moisture and to prepare a thoroughly pulverized soil before planting time.
When grown for market early planting is particularly important. It may be the means of getting a third or a half better price for most of the crop. Prices often decline very rapidly and a difference of several days earlier in reaching the market may make the average price for the season materially larger. In regions where sweet corn is grown for packing, late frosts sometimes catch the crop, and in such localities it is better to plant early and take risks of spring frosts, when replantings can be made if necessary, rather than to risk a total loss of the crop from autumn frosts.
It is customary to plant early, second early and late varieties at the same time, although some growers, especially those who produce their own seed, prefer to grow only one variety, planting at intervals of about 10 days to insure a succession of ears. There is no danger of mixing if only one variety is grown and this is a great advantage when a breeding plat is maintained.
Sweet corn is often grown in hills, but drills are preferred. Plants of the lower growing varieties may stand 10 inches apart, or perhaps slightly closer, while I foot is not too much space for vigorous sorts like Stowell Evergreen. The space between rows varies from 30 inches to 4 feet, depending upon the height of the plants. Three feet or less is ample for the early varieties, while the rank late varieties should have about 4 feet. A good stand is exceedingly important. It is best to seed freely, and thin if necessary to reduce the number of plants. Crowding is just as objectionable as to have a poor stand. When planted in hills, more than four plants should never be allowed to remain. With the larger varieties three will probably give a better yield of salable ears.
If rain falls after planting and before the plants are up, a weeder (Figure 6) should be used to break the incrustation. This implement may be employed with good results until the plants are a foot or more high. An occasional plant will be damaged, but the benefits are much greater than the injuries. The damage will be least if the weeder is used in the middle of the day, when the plants are less rigid, than earlier or later. Various other tools, the spike-tooth type and the riding cultivators, are employed in caring for the crop, and some hand hoeing is usually required.
Suckering is not as beneficial as some growers suppose, but it is generally regarded as a profitable operation. Some varieties sucker much more freely than others.
Sweet corn is often harvested before it is ready. The kernels should be plump, but not hard. It pays to exercise care in regard to this matter, for uniformity in size and degree of ripeness is an important factor in commanding remunerative prices. The crop is shipped in barrels, hampers and crates of various sizes.
Sweet corn, under favorable conditions, is a profitable crop. Prices paid by the packers range from $9 to $12 a ton, and about $3 more when the husks are removed. Maine canneries pay 2 cents a pound for the corn cut from the cob. This is the fairest way to sell sweet corn. It also encourages good breeding. Prices on the market vary from 5 to 25 cents a dozen ears. Gross receipts have been known to run as high as $350 an acre, but this is very unusual. A gross return of $100 makes corn a profitable crop, especially when the fodder is used properly on the farm. Many general farmers, who grow sweet corn on a large scale for market or for packing, cut the fodder into silage as soon as the crop is sold.