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242. Dent Maize is that type in which the split grain shows the embryo, the glossy endosperm on each side, and the white endosperm extending to the top. The grain is indented on the top, evidently because the soft endosperm shrinks in the central portion as the grain ripens, while the denser endosperm holds the sides in a straight line. The relative position and amounts of the soft and dense endosperm cause differences in the character and extent of indentation, varying from a ragged dent or projecting flap to a mere dimple or circular depression. Occasionally the grains toward the tip of the ear do not indent, although retaining their dent structure. While there is a wide variation due to climate, season, soil and variety (210), the plant usually varies in height from eight to twelve feet, generally bears but one ear and is not given to suckering unless thinly planted. This type is characterized for its deep grains, rather large diameter of ears and large number of rows, as high as fortyeight rows having been reported for individual ears. Variety differences range from eight to twenty-four rows, sixteen to twenty being the most common. Ears vary in length from five to thirteen inches, and in diameter from one and one-half to two and one-half inches. A good sized ear is eight to nine inches long and from six and one-half to seven inches in circumference at two-fifths its length from the butt. Ten inches is rather long for a dent ear, while seven inches is a good length for smaller
Dent maize: ear one-third natura1 size; grain about natural size.
varieties. It is a good ear that weighs three-fourths of a pound. It takes about 100 good ears to make a bushel of shelled maize. One hundred ears of early maturing dent maize will weigh about fifty pounds; of medium maturing, sixty-five pounds; and of late maturing, eighty pounds. One hundred selected ears will weigh sixty, seventy-five and ninety pounds respectively.
Usually the grains are wedge-shaped and deeper than broad. A typical dent grain is five-eighths of an inch deep by three eighths broad and one-sixth of an inch thick. The most common colors are yellow and white, although red grains or those striped with red or similar colors occur in some varieties. Sports of this sort are not uncommon in yellow and white varieties and in some instances this character has been fixed by selection. There is considerable variation in weight of grain: a range of thirty-five to forty-five grams per 100 grains, or from 1,000 to 1,300 grains per pound, is common.
The season ranges from ninety to 150 or even 160 days. There is a wide variation in the same variety in different latitudes and different seasons in the same latitude. In the maize belt States early varieties usually mature from 100 to 115 days, medium varieties from 11o to 135 days and late varieties from 130 to 145 days in ordinary seasons. Dent and flint types furnish all the commercial grain of maize, as well as practically all of the maize fodder and maize ensilage. Only a small fraction of the total is furnished by the flint type.
243. Description of a Good Dent Ear.—While variety differences are permissible, there are certain characteristics that are more or less desirable in all varieties. It should be borne in mind that while these ideal characteristics are desirable, other things being equal, their lack of perfection may not prevent a variety from producing high yields or having in other particulars desirable qualities. Cows without horns are desirable, but this does not prevent cows with horns being good milkers. The ear should taper uniformly from butt to tip and should be as near as possible cylindrical. Such an ear holds the largest amount of grain and contains the largest percentage of grain in proportion to cob, other things equal. Both the butt and tip should be well filled for same reasons and because this indicates full development and maturity as well as adaptation to soil, latitude or season. (217) Excessive length is not desirable when obtained at the expense of poorly filled butt and tip. A good proportion between circumference and length is three to four, or a circumference of six inches for an ear eight inches long. A good size for the circumference of the cob is from three and twothirds to four and one-third inches. The cob should be neither too large nor too small. It is evident that of two ears of equal size and compactness, the one with the small cob will contain the more grain. On the other hand, while small cobs usually at fifty-three to sixty-three pounds of grain for seventy pounds of air-dried ears have been noted.1
objectionable, as they usually carry large percentages of water, thus lowering the keeping quality of the grain and its vitality for seed. This is likely to be true of ears with enlarged butt and ears that are distinctly tapering, as well as making them more difficult to husk on account of the size of the juncture with the shank In a good ear the shelled maize will occupy the same space as the ear before it was shelled. It is a good relationship where the depth of grain is one-half the diameter of the cob or the circumference of the ear twice the circumference of the cob. The legal standard in most States is seventy pounds of ears and fifty-six pounds of grain per bushel, or a ratio of cob to grain of one to four or a trifle more. Variations
Shamel states that grains with thin tips have low vitality and are low in per cent of fat and protein and high in starch.2 While it is evident that, other things equal, wide sulci or space between rows will reduce the percentage of grain to cob, it happens that some varieties, as, for example, Hickory King, with large space between rows, have relatively small cobs; hence large' percentage of grain although small weight per ear. The roughness of the ear is dependent upon the character of the indentation of the grain. Grains which cause rough ears are usually longer but somewhat less compact than those causing smooth ears. While a smooth ear is pleasanter to husk, there are some excellent varieties whose ears are rough. Aside from its influence upon husking, its importance would seem to be due to the cause which produced it. If a rough ear was caused by lack of proper development and resulted in chaffy, loose grains, it is to be looked upon as undesirable.
244. List of Varieties of Dent Maize.—Four white and three yellow varieties have been recognized as distinct varieties by the Illinois Corn Breeders' Association, as follows: (White) Boone County White, Silver Mine, White Superior; (Yellow) Learning, Reid's Yellow Dent, Riley's Favorite and Golden Eagle.
Following is a list of varieties of dent maize recommended principally for grain production by the stations indicated, including, where possible, the color of the grain of each and the number of years tested:
1 Miss. Bui. 33, p. 76.
I Manual of Corn Judging, p. 63.