Potatoes.
The varieties of the potato cultivated in Britain, having been chiefly derived from Ireland, where the plant is nearly secure from frost from the middle of April till the end of November, the want of new and more hardy varieties has long been felt; and the Horticultural Societies both of London and Edin burgh have offered premiums for the production of such varieties. A hardy potato is, however, still a desideratum.
Various new kinds, some of them possessing de sirable properties, have indeed, of late years, been raised by cultivators in different parts of the country ; but to particularize these seems unnecessary. It may, however, be remarlred, that while the Ash leaved and American Earlies are the kinds with which the Edinburgh market is principally supplied in the months of July and August, a superior early variety abounds even in the neighbouring town of Perth. This is called the Royal Dwarf. The plant is distinguished by its broad shining leaves, and by the first tubers forming a cluster of three or four immediately at the bottom of the stem. This last circumstance renders it easy to rob the plant of the earliest and largest potatoes, without disturbing the roots, leaving it to produce a sufficient crop of se condary tubers for seed-stock. The royal dwarf is a dry potato, or rather mealy than waxy ; but this is a quality which recommends it to many persons. It is generally fit for use a fortnight earlier than the ash-leaved or the American early. It may be re marked, that the most desirable early varieties are such as do not show a disposition to send forth flowers ; that portion of the substance and vigour of the plant which would go to the formation of flowers, being diverted to the production of tubers.
A very important fact in the cultivation of pota toes was observed, about the year 1806, by the late Mr Thomas Dickson of Edinburgh, viz. that the most healthy and most productive plants were to be obtained by employing as seed-stock tubers which had not been thoroughly ripened, or even by plant ing only the wet or least ripened ends of long-shap ed potatoes. Mr Knight has likewise clearly shown the advantage of using, as seed-stock, potatoes which have grown late in the preceding year, or have been only imperfectly ripened. It is important to know, that if a valuable kind seem to be exhausted or to have lost its good qualities, it may be restored mere ly by planting the tubers late in the summer, and preserving the produce of this late-planting for seed stock.
The forcing of early potatoes on hot-beds has long been practised ; but it is attended with considerable trouble and expence. Small supplies of young po tatoes are now commonly produced, during winter, in boxes placed in the mushroom-house, in the shade at the back of a hot-house, or in a common cellar, if beyond the reach of frost. In October, old pota toes are placed in layers in the boxes, alternating with a mixture of tree leaves, sand, and light mould, until they be full. Vegetation soon proceeds ; and there being no opportunity for the unfolding of stems and leaves, the energies of the plants are expended in the production of young tubers. Before mid winter, these often attain the usual size and appear ance of early potatoes; but they are much inferior, being of a watery taste, and having little or no flavour.
It is much to be wished that we should be ac quainted with improved modes of storing the princi pal autumnal crop, so as to preserve the quality un altered till the following summer. The Reverend Dr Dow, of Kirkpatrick-Irongray, has devised a mode which certainly merits attention. In the au tumn, the potatoes are put into small pits, holding about two bolls each. These pits are formed under the shade of a tree, or on the north_ side of a high wall ; and they are covered with straw and earth, according to the usual mode of pitting potatoes. In the end of April, or beginning of May of the follow ing year, the potatoes are examined ; all buds are rubbed off, and such as show any tendency to spoil are thrown out. The pits being cleaned out, are nearly filled with water ; when this has been absorb ed, the potatoes are returned into them ; at the same time, every quantity is watered as it is laid in, and the whole covered with earth, as before. The pits must, in this way, long remain cool. The abundant supply of moisture is, however, contrary to establish ed prejudices as to the mode of keeping potatoes ; and on this account, many have probably been de terred from adopting the Doctor's plan. But, in this way, we are assured, the potatoes are kept not only plump and unaltered in taste, but the dry kinds, after being seven months in the pits, come out unimpaired, and appear on the table as mealy as ever.