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sylvania Station between seed from threshing machines and that selected by hand.1 At the Tennessee Station, with two varieties, while in general the yield was in favor of the larger seed, it was not uniformly so. The evidence showed that the largest grains usually came from the largest spikes, but the seed from the largest spikes did not always give the largest yield.2 Middleton, at the University College of Wales, obtained nearly double the yield of wheat from large seed than from small seed.* Lubanski has experimented in Russia with winter wheat, barley, oats and sugar beets, and finds the yield, and to some extent the quality, influenced in favor of large seed.4 Desprez, at Grignon, France, has conducted experiments with several varieties for several years, the general results being in favor of the large seed. Different weights of seed were sown with each variety, but the same weights of large and small seed were sown: thus no two plats received the same number of seeds.5 In 1900, Deherain reports from the same station but slightly better results from large seed.6 Cobb reports tests of various sizes of wheat grains and concludes that the superior yield from large, plump grain is sufficient to justify the cost of first-class cleaning machinery.7
The results of foreign experiments are rather uniformly in favor of large seed: some experiments showing rather striking results. A careful analysis of all American experiments appears to show that where large and small seed are obtained by the use of the ordinary fanning mill the yield has been only slightly if at all increased on account of the seed, while apparently, where greater care is taken in the selection, a moderate increase
1 Penn. Rpt. 1893, P-It2
2 Tenn. Bui. Vol. XIV, No. 2 (1901), pp. 42-47.
'University College of Wales Rpt. 1899, pp. 68-70.
* Selsk. Khoz. i Lyesov. 200 (1901), Mar., pp. 611-617. (E. S. R. XIV, 432.) S Jour. Agr. Prat. 2 (1897), No. 37, pp. 416-420.
• Ann. Agron. 26 (1900), No. r, pp. 20-23. (E. S. R. XII, 233.) 'Seed Wheat, pp. 1-60: Sidney, 1903.
in the yield has been obtained. In a number of experiments the influence of the number of seeds per acre has not been eliminated.
If the grains of the spikelets of wheat be designated by numbers according to the distance from the spikelet, it has been found that grains occupying the second place are the heaviest; that those in the first and the third place are about equal in weight; while grains in the fourth and the fifth place, if any, are still lighter. It is also found that of grains occupying the same relative position, those on the lower half of the spike are the larger. The following table gives results with two varieties of wheat:1
It would thus appear that small and large grains come from the same plant, varying in size because of their position, as do the grains of maize on the ear. If the plant and not the individual seed is the unit of reproduction, small seeds from productive plants will be better than large seeds from unproductive plants, provided productivity is due to heredity and not to environment, except in so far as large seeds may give the plant a more vigorous start in life. (43) It has been shown, however, that on an average, the larger spikes contain the larger grains, so that in selecting the larger grains the larger number of them would come from the larger spikes.8
134. Treatment of Seed.—Before sowing, the seed should be carefully screened in a fanning mill, or wheat grader, or
1 Kurt Rumker: Jour, of Landw. 38 (1890), p. 309.
2 Seed Wheat, pp. 1-60: Sidney, 1903.
preferably both, not only to eliminate all small and undeveloped grains, but to remove weed seeds and diseased grains, if any.
If seed comes from plants that have been affected with stinking smut (149), the seed should be immersed in cold water and
stirred, when the smut balls will rise to the surface and can be skimmed off. The seed should then be sprinkled or immersed thirty minutes in a solution of formalin mixed at the rate of fifty gallons of water to one pound of formalin (forty per cent solution of formaldehyde). Blue stone solution or hot water may be used in place of the formalin. (149) In case wheat has been affected with the loose smut the wheat may be given the modified hot water treatment. (148) It is necessary in such case to use one-half more seed to replace seed injured by treatment. Since loose smut is usually not very destructive, it will probably be rarely advisable to resort to treatment of seed for loose smut.
135. Wheat Seeding Machinery.—For broadcasting small areas, the hand grass seeder will do satisfactory work when it is not too windy. The usual horse broadcast seeder is not unlike the wheat drill, except the wheat is scattered directly from the hopper onto the surface of the ground instead of being conveyed by means of hoes underground. Standard widths are eight,
\ seed wheat grader suitable for use by wheat growers. Wheat is sorted according to size of grains and not according to specific gravity. The screen is a cylinder of perforated sheet metal, actuated by the crank E. A brush, AA, an important feature, is held against the screen by the springs, BB. Meshes ranging from two to three millimeters may be used; where only one size is supplied, 2.5 millimeters (one-tenth inch) should be used for American wheat. (After Cobb.)
The broadcast grain seeder.
eleven and fourteen feet. The wheat drill is made in three general forms: (1) hoe drills, (2) disk drills, and (3) drills with runners or shoes. The drill with runners also usually has a wheel behind each runner which is designed to press the earth firmly about the seed. Wheels are also sometimes used on disk drills. Where these wheels are used they are known as press drills.
The first form of drill is made with shovels, called hoes, which open the ground and permit the seed to be introduced in a stream into the soil behind each hoe. The hoe drills will operate
under a larger number of conditions, but are heavy of draft and are liable to clog when the soil contains much rubbish. The disk drills draw easier, and are not so liable to be clogged with rubbish, but are not so well adapted to stony or hilly land and will not work so well in wet soil. The drills with runners have not been extensively employed. The hoes are made so as to run either seven or eight inches apart. When the hoes are seven inches apart, nine, ten and eleven hoes, and when eight inches apart, six and eight hoes, are standard sizes.
There is no evidence to show that one width of seeding is better than another. Eight-inch drills are less liable to clog with rubbish than seven-inch, although the zigzag arrangement on both sizes lessens the importance of this difference.
Wheat drills may be purchased with and without grass seeder attached, and with and without fertilizer drill. The grass seeder
scatters the seed broadcast either in front or behind the drills as preferred, while the fertilizer is conveyed into the ground by the same channel as the grain. There are a number of different methods of conveying the grain and the fertilizers from their The hand seeder. respective hoppers, most of which are
satisfactory. Those forms which vary the amount sown by means of variation in the sizes of cog wheels used are probably the best. These drills are usually intended to sow the seeds of all ordinary field crops.
136. Cultivation.—The cultivation of wheat much as we cultivate maize in this country was formerly vigorously advocated and somewhat practiced in England. This practice has never been common in the United States, and only one station (Alabama) out of seven which have reported trials has found it beneficial as compared with the usual method. In most cases it has been found decidedly detrimental. A number of stations have reported in favor of harrowing wheat drilled in the ordinary manner one or two weeks after seeding. The Ohio Station reports that harrowing winter wheat in the spring did no harm.
137. Rolling.—Winter wheat may be rolled in the spring, when there is much heaving of soil, in order to pack the soil about the roots. The cost of thus smoothing the surface may often be repaid by the increased facility with which the crop can be harvested. When grass seed is sown with the grain, rolling should never be neglected.