Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/391

Rh LOOT CDOPS.] with snow in an ice-house for many months. Seeds and plants when kept in this way during winter, and then brought into the warm air of summer, germinate and grow with great rapidity. Mr Stewart had also made experi ments with animals, and he found that the chrysalis so treated produced a moth in eleven days after being brought into the atmosphere, while another chrysalis of the same moth did not do so for three or four months after. In arctic regions the rapid growth of plants during the short summer was well known. Professor Simpson alluded to the importance of similar experiments being made on the different kinds of grain. He referred to the rapidity of harvest in Canada and other countries where the cold lasted for many months, and he was disposed to think that if grain was kept in ice-houses during the winter, and sown in spring, there might be an acceleration of the harvest.&quot; The suggestion for the treatment of seed corn is cer tainly deserving of trial ; but the known difficulty of hinder ing the premature germination of potato sets in the ordi nary method of storing them seems to point to them as the peculiarly appropriate subjects of such an experiment. Potato drills should not be less than 30 inches wide, nor the sets less than 10 or 12 inches apart in the rows. The usual practice is to take the sets to the field in sacks, which are set down at convenient distances for replenishing the baskets or aprons of the planters. When a large breadth is to be planted, a better way is to have the sets in carts, one of which is moved slowly along in front of the planters. A person is seated in the cart, who has by him several spare baskets which he keeps ready filled, and which are handed to the planters in exchange for empty ones as often as required. This greatly economises the time of the planters, and admits of a greater amount of work being accomplished by them in a day. Single-bout drills are quite sufficient, so far as the success of the crop is concerned. So soon as the young potato plants are fairly above ground, the drill- grubber should be set to work and followed up without delay by hand-hoeing. Mr Wallace, North Berwick Mains, a most successful cultivator of potatoes, has for many years taken off all the shoots, save one, from the potato sets as they appear above ground, and the prunings are used in filling up blanks; the result has been that the produce of the solitary stem is both larger and of more equal size and quality than when the shoots are all left. A turn of the horse-hoe and another hand-hoeing after a short interval are usually required, after which the common practice is to earth up the rows by the double mould-board ploughs. There is reason to believe that this latter practice usually does harm rather than good. It no doubt prevents the uppermost tubers from getting greened by exposure to the light, but it is believed that the injury inflicted on the roots which spread into the intervals betwixt the rows far more than counterbalances any benefits that result, or have been supposed to result, from this earthing up. After the plants are a foot high, a slight stirring of the surface to keep down weeds is all the culture that is admissible con sistently with the well-doing of the crop. When the crop is matured, which is known by the decay of the tops and the firmness of the epidermis when the tubers are forcibly rubbed by the thumb, advantage is taken of every dry day in harvesting the crop. With small plots, the fork is certainly the most efficient implement for raising the tubers; but on the large scale, when expedition is of great consequence, they are always unearthed by the double mould-board plough. Alternate rows are split open in the first instance, and then the intervening ones, as the produce of the first is gathered. When a convenient breadth has thus been cleared, a turn of the harrows is given to uncover such tubers as have been hid from the gleaners at the first going over. This work is now very 3G5 generally accomplished by means of a bulking-plough divested of its wings, and having attached to its sole a piece of iron terminating in radiating prongs. This being worked directly under the row of potato plants, unearths the tubers, and spreads them on the surface by one opera tion. The potatoes are gathered into baskets, from which they are emptied into carts and conveyed at once to some dry piece of ground, where they are piled up in long narrow heaps and immediately thatched with straw. The base of the heaps should not exceed a yard in width, and should be raised above the surface level rather than sunk below it, as is very usually done. As the dangers to be guarded against are heating and frost, measures must be taken with an eye to both. The crop being put together in as dry and clean a state as possible, a good covering of straw is put on, and coated over two or three inches thick with earth, care being taken to leave a chimney every two yards along the ridge. By thus keeping the heaps dry and secure from frost, it is usually possible, even yet, to preserve potatoes in good condition till spring. Such diseased ones as have been picked out at the gathering of the crop can be used for feeding cattle or pigs. The fact that pigs fatten appa rently as well on diseased potatoes when cooked by steaming or boiling, as on sound ones, is certainly a very important mitigation of this dreaded calamity. There are several varieties of the potato, such as &quot; yams,&quot; &quot; lumpers,&quot; &quot;mangel-wurzel potato,&quot; &amp;lt;fec., which, although unfit for human food, are much relished by cattle, and which, from their abundant produce, healthiness, and great fattening quality, are well deserving of being more generally cultivated for the purpose of being used in combination with turnips and other substances in the fattening of cattle. The turnip crop of recent years has been nearly as much diseased as the potato crop, and as one remedy against &quot; fingers-and- toes&quot; in the former is to let longer intervals of time inter vene before their recurrence in the same field, and as it has been ascertained that an acre each of beans, potatoes, and turnips will produce more beef than three acres of turnips alone, it is worthy the consideration of those con cerned whether it would not be prudent to substitute a crop of these coarser potatoes for a portion of their turnip crop on fields or parts of fields that have borne diseased turnips in previous rotations. Eight tons per acre is a good crop of potatoes. Section 2. Turnips. The introduction of turnips as a field crop constitutes one of the most marked epochs in British agriculture. To the present day no better criterion exists by which to estimate its state in any district, or the skill of individual farmers, than the measure of success with which this or other root crops are cultivated. We have already, in our section upon fallowing, described in detail the process of preparing the soil for drilled green crops. Referring the reader to what is there said, we now proceed with our description of turnip culture. Previous to the introduction of bone-dust and guano, farm-yard dung formed, in the majority of cases, the only available manure for the turnip crop. It was almost in variably formed into heaps in the field to which it was to be applied, and repeatedly turned, as great stress was laid on having it well rotted. The introduction of these invalu able portable manures has, however, not only immensely extended the culture of the turnip, but has materially modified the course of procedure. On the first introduc tion of bone-dust the practice was to use the fold-yard dung as far as it would go, and to apply bone-dust alone, in quantities of from sixteen to twenty bushels per acre, to the remainder of the crop. Guano, too, for a time was used to some extent on the same principle; but now it is