Set-I.—The seed tubers may be planted whole or cut; a piece weighing about three ounces, or as large as a good-sized egg, and having at least one good eve, being the most profitable. It pays to dig the heaviest-yielding plants by hand and save their progeny for seed. Heavy-yielding plants will gen erally reproduce heavy yielders, and vice versa. The tubers used for seed should he sound, free from coarseness and second growth and be true to name. If planted in rows thirty-six inches apart and the plants fifteen inches asunder in the row, it will require about seventeen bushels of seed per acre.
The storage of seed is a very important factor. It should be kept in a cool, well-ventilated place to prevent much loss of weight, until ten or four teen days before planting time, when it may be spread on the barn floor or in some well-lighted place, which will e,use the seed to begin to grow before planting. The shoots made under such con ditions will be very smell. If the seed is scabby, or from scab-infested land, it may be treated with formalin. [See next page under Enemies.] Seeding.—Planting may be done by hand or machinery, the latter being by far the cheaper way, although still unsatisfactory, because there is no planter, known to the writer which will handle a seed piece of the size required. On sandy loam soils the seed may be planted three or four inches deep, and level culture adopted with profit. Under other condi tions, planting two or three inches deep and subse quent drill culture may be good practice. Where irrigation is practiced, rows are often four feet apart, but under other conditions three feet is generally considered ample.
The time of planting depends on whether an early, mid-season, or late crop is being grown. Generally the early crop is put in as soon as settled weather conies and the ground is workable. ('are must be taken that the plants are not frosted, as they are sensitive. The late crop is planted in the middle or latter part of May in the North. [The planting dates throughout the country are given in Chapter VII, pages 133-140.] Subsequent care.—Cultivation begins a few days after planting and consists of harrowing the land with the spike-toothed harrow or the weeder to destroy all weeds before they are well started, a policy that should be rigidly maintained. The weeder may then be used once a week until the plants are seven to ten inches tall. By this time the plants may have been cultivated once, with the cultivator set three or four inches deep ; they should receive subsequently about four more culti vations, each one shallower than its predecessor, the second one being not more than two to two and a half inches deep, thus giving a total of about five cultivations at intervals of seven to ten days. By
this time the tops will meet in the rows.
I n choosing a vari ety to plant, a number of factors must be consid ered. Among these may be men tioned : (1) Good cook ing quality and flavor. These are partly influenced by the soil, season, fertilizers, ability to mature before frost and other factors.
(2) Yield. This is dependent on adaptation of the variety to its environment.
(3) Ability to resist diseases. No blight-proof variety exists, but some possess more resistance than others.
(1) Color of skin and• tuber. Some markets re quire one color, others another.
(5) The nature of the skin. A netted or rough skin is preferred.
(6) The shape. Some markets discriminate in favor of a particular shape. Varieties are some times classified according to shape, as round, flat round, kidney and the like.
(7) Depth and frequency of eyes. Deep and numerous eyes are not economical in peeling.
(8) Time of maturity. In the northern states varieties are classified according to the time taken to form salable tubers ; thus, "earlies" are ready to harvest in 70 to 90 days after planting, "second earlies" in 90 to 130 days, while late varieties may sometimes continue to grow for 200 days.
(9) The character of the foliage and top. Straight upright stems bearing thick hard leaves are desired, since such are probably less liable to diseases, and are easier to spray.
(10) The vigor. The variety and the strain se cured must be vigorous and not subject to second growth of the tubers.
(11) True to name. The variety should be what it is purchased for.
Many thousand varieties of potatoes have been developed during the past hundred years. Among prominent varieties of today may be mentioned : Dulles: Bliss Triumph, Early Ohio, Six Weeks Market, Early Thoroughbred, Bovee, Reliance, Crown Jewel, Noroton Beauty, Burpee Extra-Early, Eureka, Early Rose (some strains). Second earlier: Burpee Extra-Early, Eureka, Beauty of Hebron, Polaris, Irish Cobbler, Early Rose (some strains). Late: Carmen No. 3, Sir Walter Raleigh, Rural New Yorker No. 2, Vermont Gold Coin, State of Maine, Green Mountain, Freeman, Burbank.