22

PLANTS USEFUL IN AGRICULTURE.

was ever achieved bv all the military exploits performed before or*iooe that period*. It has not only been the means of increasing thewealth and strength of nation?, but more than once prevented a fa-mine in this coi ntry when suffering from a scarcity of bread-corn, andwhen most of the ports which could afford us a supply were shut bythe ambition of a powerful enemy.

63. BRASSICA Napus. Turnip. —Turnips afford the best feed fc*sheep in the autumn and winter months. It is usual to sow them as *preparatory crop for Barley, and now very frequently for a crop 01Spring Wheat, Turnips are not easily raised but where some kind ofmanure is used to stimulate ihe laud. In dry seasons the crop is oftendestroyed by the ravages of a small beetle, which perforates the coty-ledons of the plants, and destroys the crop on whole fields in a few hours.

Many remedies against this evil are enumetated in our books onhusbandry. The best preventative, however, appears to be the puttingmanure on the ground in a moist state and sowing the seeds with it, morder to excite the young plant to grow rapidly; for the insect does nothurt it when the rough leaf is once groun. T have this season seen *fine field of Turnips, sown mint with dung out of a cart and ploughedin ridges. The seeds which were not too deeply buried grew and escapedthe fly; when scarcely a field in the same district escaped the ravagesof that insect. Turnips are sown either broad-cast or in drills. It takesabout four pounds of seed per acre in the first mode, and about half thequantity in the second.

There are several varieties of turnips grown for cattle; the most strife'ing of which are, the White round Norfolk ; the Red round ditto ; theGreen round ditto; the Tankard; the Yellow. These varieties are nearlythe same in goodness and produce : the green and red are considered asrather more hardy than the others. The tankard is long-rooted ardstands more out of the ground, and is objected to as being more liableto the attack of early frosts. The yellow is much esteemed in Scot-land, and supposed to contain more nntrimentf. The Stone and Dutchturnips are grown for culinary purposes, and are also sometimes sown af'ter the corn is cleared, as being small and of early growth; these in suchcases are called stubble turnips, and often in fine autumns producea considerable quantity of herbage. For a further account of the cul-ture &c. see Dickson's Modem Husbandry, vol. ii. p. 639.

There is nothing in husbandry requiring more care than the savin?seeds of most of the plants of this tribe, and in particular of the Ge-nus Bras-ica. If two sorts of turnips or cabbages are suffered to gro*and bloom together, the pollen of each kind will be snlhciently mix f( *to impregnate each alternately, and a hybrid kind will be the product

* The Potatoe was introduced by Sir Walter Raleigh, on his retui* 8from the River Plate, in the year 1586.

■f* The usual season for sowing the above varieties is within a fort"night or three weeks after Midsummer.