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vigorously. The vitality may be injured and the seed still sprout. The less the percentage of seed sprouting, the less the vital power. The Illinois Station found in the case of sweet maize that when ninety-five per cent of the seed grew in the greenhouse, but seventy-five per cent of the seed which grew in the greenhouse grew in the field; while where fifty-two per cent grew in the greenhouse test, only fifty-five per cent of those which grew in the greenhouse grew in the field. A perfect stand of vigorous seedlings is an important element in successful culture of maize. (303) The New York State Station reports :
“While in germination, in one trial, the vitality as expressed in per cents was precisely the same as between two lots of 500 seeds each, the one corn from the crib and the other thoroughly dried over a radiator, viz., 94 per cent, yet when the same corn was planted in the earth the difference became very marked, the corn from the crib giving but 20 per cent vegetation and the same corn kiln-dried giving 80 per cent vegetation. The difference was even more marked in the growth, che corn from the crib attaining a height of only three inches, while that from the kiln-dried seed had reached the height of five inches in the same time."
270. Germination.–Sturtevant has shown that the different types of maize would germinate at a temperature of 41° to 43.7° F. in from ten to twenty days. When the temperature varied from 48.5° to 58.5° F., from five to nine days were required for germination. At these temperatures sweet maize required somewhat longer time to germinate than the other types. Sachs and Ward give the highest temperature at which maize will germinate, 115° F., and 91° to 93° F. as the temperature at which germination is most rapid.
271. Treatment of Seed. There are four purposes for which seeds have been treated with chemicals; viz., (1) to hasten germination; (2) to protect the seed from insects and other animal pests; (3) to prevent the attack of fungi, and (4) to furnish plant food. The evidence as to the influence of chemicals in all of these directions as relates to maize seed is more or less conflict
1 N. Y. Rpt. 1886, p. 40. 2 Bul. Torr. Bot. Club Vol. XXI, No. 8, p. 234.
ing, but in practice it is not generally desirable to treat the seed in any way.
272. Method of Testing Seed.— If the plumule and radicle of the embryo are carefully exposed by means of a sharp knife, these parts will be white and plump. Any discoloration or wilting is evidence of injured vitality. To determine vitality definitely, seed should always be tested before using. This may be done by any method
Homemade germinating apparatus: consists which furnishes proper condi of a shallow tin basin, which is given two tions of heat, moisture and air.
coats of mineral paint to prevent rusting.
The bottom of the basin is covered with A satisfactory method is to fill water and a small flat-bottomed saucer of any receptacle similar in size
porous clay is placed inside. Seeds are
placed between two layers of moist blotand shape to a dinner plate ting paper or flannel cloth. A, complete; with sand. Pour on water until B, section. (After Hicks.) it covers the surface of the sand. Gently drain off water. Place grains in the moist sand, thoroughly covering them, and
cover receptacle by inverting a similar one over it to prevent too rapid evaporation and place in a temperature of 80° F. If ninety-five per cent of the seed fails to germinate in five days, the seed is unsatisfac
tory. If shelled grain is to be tested, Cigar box used for testing germina- take 1oo grains after thorough mix
tion of maize. Grains may be placed ing. If ears are to be tested, take between moistened newspapers or cloths, preferably flannel. (After three grains from each of twenty-five Holden.)
to fifty ears, taking a grain from butt, middle and tip. In some cases it may be desirable to test each ear separately by taking ten grains from each ear. In no case should an ear be used in which nine out of the ten grains failed to germinate under conditions named. ,
273. Seed from Different Parts of the Ear.-Grains on an ear equally represent inherent qualities of the plant which produced them. They should, under favorable conditions, produce plants having similar characteristics. The butt grains being larger and the tip grains smaller, differences in the food supply exist which it was thought might modify the ability of the seed to survive unfavorable conditions or cause variation in the vigor with which the young plant was started upon an independent existence. It has also been suggested that the grains on the middle of the ear are more likely to be fertilized with pollen from the same plant and that this closer breeding might tend to decrease the yield from plants grown from such grains. In no case have any considerable differences in yield been obtained from using grains from different parts of the ear. The results given below seem clearly to demonstrate that there is no advantage in planting grains from any special portion of the ear, provided equal stands are obtained.
Average Yield per Acre of Seed from Different Parts of Ear
The Kansas Station found that under field conditions eightysix per cent of the butt grains, ninety per cent of the middle grains and seventy per cent of the tip grains produced plants. The Iowa Station found that when all the grains of an ear
1 Kan. Bul. 64, p. 238. 2 Iowa Bul. 68, p. 278.
were used in the corn planter, the number of grains dropped at one time varied from one to six grains, the planter dropping three grains to the hill sixty-six times out of a hundred. When only the middle grains of the ear were used, the planter dropped two grains eight times and three grains ninety-two times to each hundred hills. Since uniformity of stand is essential to maximum yield, it is therefore good practice to discard the largest of the butt and the smallest of the tip grains. It is also found that in order to secure uniformity of stand it is essential to select ears having grains of uniform size. It was found that when long and short grains were mixed together, the planter dropped three grains seventy-five times out of one hundred; while when planted separately with proper plates for each, the planter dropped three short grains ninety-five times out of one hundred and three long grains ninety-two times out of one hundred.
274. Limited Distribution.—That there is a wide difference in distribution of maize as compared with other cereals is shown in the following table giving average production in million bushels by continents for five years, 1898-1902 inclusive:
The fact that sixty-six per cent of all the maize raised in the United States is grown in seven maize surplus States—Ohio, Indiana, Illinois, Iowa, Missouri, Nebraska and Kansas—is a further indication of its limited distribution. It is this limited distribution, coupled with the fact that maize will produce about twice the food nutrients of any of our other cereals per acre, that makes lands especially adapted to the culture of maize command relatively high prices.
275. Causes Limiting Distribution.—Among the causes limiting successful cultivation are temperature and sunshine, rainfall and physiographical features, including soil. It is only when these several factors are properly combined that the culture of