Imágenes de páginas
PDF
EPUB

ience of comparison, the average yield per acre of wrapper leaf is included from Table VII, which gives the methods of fertilization on each plot, total yield of all grades of leaf on each plot, etc.

Somewhat similar experiments have been made by the Pennsylvania experiment station, but were interrupted for lack of funds. The whole subject of feeding the tobacco plant is fully discussed in Chapter VI, but some further points applying specially to cigar leaf should be mentioned here. Especially would we* reiterate that the proper use of appropriate commercial fertilizers or agricultural chemicals is not injurious to either quality or quantity of the yield. On the contrary, such use improves the quality and increases the yield. But "the proper use of appropriate fertilizers" covers many things that can only be learned by long experience, and cannot be taught in books. This matter has been closely studied by practical farmers and by fertilizer experts and manufacturers, especially during the past few years. In addition to the popular fertilizers previously used with general satisfaction by careful growers, this work has resulted in bringing out some new "tobacco ash" mixtures, for which much is expected.

The first of these new mixtures to be announced was Mapes "tobacco ash constituents," designed to be used in connection with cottonseed meal or any material supplying ammonia. The raw materials generally used by the most successful tobacco growers in connection with cottonseed meal, and also employed at Poquonock, are double sulphate of potash (containing sulphate of potash and sulphate of magnesia), high grade sulphate of potash, cottonhull ashes, wood ashes and bone meal. Both wood and cottonhull ash vary in quality, and are at times the most expensive forms of potash. These materials also may contain much more magnesia than the crop requires. Jenkins declares that an excess of magnesia in the plant is known to be injurious unless lime is also abundant. An average yield of tobacco takes some 30 pounds of magnesia from an acre, and this occurs mostly in the leaf. Yet 1500 pounds of cottonhull ashes, the amount usually used per acre, supplies about 165 pounds of magnesia, and less than one-half as much lime. The double sulphate of potash, in equivalent quantities, carries about 190 pounds of magnesia. "If too much magnesia is present in the leaf, it may show in the form of the so-called 'light mold' on the leaf when it comes out of the case, greatly damaging its salability, though not materially damaging its qualities for wrappers. This is not a true mold, but is a malate of magnesia—an effloresced crystalline matter which has come out of the leaf tissue." Whether this is caused by too much magnesia in the soil or fertilizers is not definitely determined, though such is the belief of some who have given up the use of cottonhull ashes in consequence. The high grade sulphate of potash, on the other hand, contains little or no magnesia.

As a substitute for the foregoing articles, this "tobacco ash constituents" has been prepared, 1000 pounds of it supplying 150 pounds actual potash, phosphoric acid 57 pounds, lime over 200 pounds, ammonia 6 pounds, magnesia 20 to 30 pounds. The lime is in the form of a finely powdered carbonate of lime, which is preferred for the reasons fully set forth in Chapter VI. This "tobacco ash constituents" is thus intended to be free from all objectionable characteristics of the substances usually used, and 1000 pounds of it, applied with 2000 pounds cottonseed meal, will be found to supply in liberal excess all the plant food required for an acre of cigar-leaf tobacco, and in thoroughly tested forms. Such a mixture will furnish of ammonia 156 pounds, phosphoric acid 77 pounds, and potash 170 pounds; while a crop of 2700 pounds of cured leaf and dried stalks per acre will contain 118, 16 and 138 pounds, respectively, of these elements.

Another attempt in the same direction is Bowker's "tobacco ash elements without ammonia," 1000 pounds of which are guaranteed to contain of soluble actual potash 160 pounds, phosphoric acid 60 pounds, lime 300 pounds, magnesia 30 pounds. This mixture is guaranteed "to be composed principally of wood ashes and bone ash, containing potash in the form of carbonate, and the phosphoric acid largely in available form, besides carbonate of lime and magnesia in the same form as in cottonhull ashes, and with it sufficient excess of lime to meet not only the wants of the tobacco crop, but also to counteract any acid condition of the soil, and to improve its texture and mechanical condition."

It will be seen that both these mixtures are free from the substances which have proven objectionable to the tobacco crop at the Poquonock experiment station— acids, chlorine, excessive magnesia, and deficiency of lime. It is recommended to plow in such mixtures two weeks before setting plants. If the fertilizer is only harrowed in, no harm need be feared if the quantity is moderate and seasonable showers fall; but if you get caught with a dry spell after setting, more or less damage follows. "But," says Jenkins, "be the season wet or dry, the crop will be likely to get the full benefit of fertilizer which has been plowed under, for the roots will find it." Indeed, tobacco has a widespreading root system, in addition to its taproot, and this is sufficient reason for broadcast applications of manures or fertilizers plowed under or thoroughly harrowed in.

A substitute for cottonhull ashes, or other forms of tobacco ash ingredients, also a substitute for cottonseed meal, or castor pomace, is put out by Mr. Bowker as modification of his "ash elements." It has ammonia, in addition to the ash elements, serving as a general for-

[graphic]

tilizer and starter. It is recommended to use 1000 pounds of this mixture with 1500 pounds of cottonseed meal per acre, the meal and half of the fertilizer being plowed under, and the rest of the fertilizer applied as a starter, and harrowed into the soil just before the plants are set out. The Mapes tobacco starter, for tobacco beds and for plants at setting out, has also been much used, and is serviceable in giving plants a prompt start. Such a start is important, as only the earlier grown and fully matured tobacco cures light and glossy under usual conditions.

More evidence that leaf of the best quality can be raised on commercial fertilizers, is shown by the fact that the largest prices in recent years have been for Connecticut leaf manured in this way. Special attention is directed to the magnificent Andross crop of broadleaf grown in the celebrated East Hartford section, an engraving of which (from a photograph taken for this work), appears on Page 400, while the typical plant of Connecticut broadleaf shown in Plates I and II, Pages IO and 23, was from this crop. The fertilizer used was 4000 pounds of tobacco stems per acre, with 1500 pounds of Baker's castor pomace and 800 pounds of H. J. Baker & Bros.' A. A. brand of tobacco fertilizer. Another field was treated the same way the previous year, but upon it, in 189U, manure was substituted for the stems, with 2000 pounds of pomace, which was the treatment given the fields illustrated in 1895. Mr. Andros, adds: "We generally alternate between stems and pomace, and manure and pomace or cottonseed meal. Sometimes we use manure two years and stems one year. It is safe to say that we get the cleanest, healthiest and heaviest crop the year when the stems are used. In my east field, not shown in the photograph, I used manure and pomace, but it is not as heavy as the field where the fertilizer is used."

« AnteriorContinuar »