280 



HISTORY OF THE VEGETABLE KINGDOM. 



two shoots. It is to be considered also, that the 

 poor people's sowing of potatoes seldom com- 

 mences until May, and continues but a short 

 time; so that were they to plant nothing but 

 sprouts, their stock of potatoes should be much 

 larger, to produce a sufficiency of sprouts, than 

 they generally possess, or have occasion for at 

 that season. 



Sprouts are fit for planting at any time after 

 they acquire roots sufficient to support them- 

 selves, independent of the mother-potatoes, which 

 they generally do when about three inches long. 

 Sprouts may be planted successfully in aU the 

 various methods by which potatoes are usually 

 planted; but it is not advisable to have the 

 sprouts cut in pieces. It is better to plant them 

 whole, be they ever so long, or have ever so 

 many series of roots and joints. When left 

 whole, they may be planted at greater distances. 

 They answer best when laid horizontally/, cover- 

 ing them in every instance as potato-sets are 

 treated. 



It is said that potatoes, and the sprouts of po- 

 tatoes, have been planted on the same day, and 

 that sprouts came up about three weeks sooner 

 than the potatoes. It is likewise maintained 

 that sprouts will produce as good, if not better 

 crops, than potato-sets, and more seldom fail of 

 growing; so that this branch of the subject still 

 requires additional investigation.* 



The young plants are kept fi-ee from weeds, 

 and when they are about half a foot or a foot 

 high, some earth is drawn around the lower part 

 of the stem ; little or no farther care is required 

 tUl tlie taking up of the crop. The plants are 

 suffered to remain until the roots attain to their 

 fuU growth. Tliis state is indicated by the stalks 

 beginning to decay, which usually takes place 

 at the commencement or latter end of October, 

 when the roots should be dug up for the winter 

 store. Some careful cultivators pinch oif the 

 blossoms as they appear on the plant. The good 

 effijcts of this practice have been very often 

 proved, it being supposed that the weight of the 

 tubers of each plant is increased an ounce in con- 

 sequence, or considerably above a ton per acre. 

 The cause of this result has been thus explained : 

 the fluid or sap gives sustenance alike to the tu- 

 ber and blossom, and, therefore, if a portion be 

 diverted from the formation of the blossom, it 

 will be exerted for the enlargement of the root. 



This plant may be propagated also from cut- 

 tings or layers of the green shoots ; but this is 

 not at all advantageous for any culture, except 

 in some instances, when it is required to multi- 

 ply as quickly as possible a rare sort. 



The tubers obtained from seeds are at first 

 very few and very small, and therefore seed cul- 

 tivation is by no means advisable to " the grower" 



* Sir Jolin Sijiclair on tlie Potato. 



of potatoes; but it is of great service to "the 

 breeder," who seeks to improve its quality. 



On the other hand, by cultivation from the 

 tubers a good variety may be extended and pre- 

 served after it has been once obtained ; as the 

 plant from the tuber is not a new plant, like that 

 which is procured by the operations of flowering 

 and seeding, but an identical part of the old one. 

 Though the planting tubers will not lead to any 

 new variety, it may have effects every way as 

 advantageous, for no plant profits more by 

 changes from one district to another. 



Besides improvement in quality which a judi- 

 cious change produces, it likewise often prevents 

 the most destructive disease to which the po- 

 tato is liable. That disease is known by the 

 technical name of the curl, or the curl-top, a 

 name by no means inexpressive of the appear- 

 ance of the plant when under its influence. The 

 top leaves begin to shrink just about the time 

 that the tubers should form, the young shoots 

 cease to expand, and the whole plant assumes 

 very much the appearance of the tip of a cherry 

 twig when the under leaves are assailed by 

 aphides. From the moment in which tliis dis- 

 ease appears, all farther growth in the plant 

 ceases, and though it may linger in a yellow and 

 sickly state until autumn, the produce, if any, 

 is little, and that little is of a bad quality. If, 

 as soon as the disease shows itself, the tuber 

 which has been planted be taken up, it will be 

 found much firmer and less exhausted than those 

 of the plants of the same age that are in a healthy 

 state. This at the same time points out at least 

 one cause of the disease, and suggests its remedy. 

 The old tuber has been too compact for yielding 

 to the vegetative powers of the plant. 



The curl first made its appearance in this 

 country in the year 1764, in Lancashire, where 

 potatoes had been first introduced into British 

 field culture, and had been propagated without 

 any change of seed. From Lancashire this dis- 

 ease spread over all the potato districts of Bri- 

 tain, and as the cause and cure were equally un- 

 known, there was a general apprehension that 

 the plant would be exterminated. Premiums 

 were offered by different agiicultural societies to 

 those who should point out a remedy for a dis- 

 ease so destructive; in consequence of which 

 many speculations and theories were raised, 

 which, however, led to very little practical uti- 

 lity. 



The discovery of at least a temporary preven- 

 tive, and therefore of the probable cause, was 

 made, as is believed, more from accident than de- 

 sign, in the neighbourhood of Edinburgh. Some 

 of the growers in that situation were in the habit 

 of procuring seed potatoes from the cold moor- 

 land districts, and fields planted with these were 

 free from the curl. Upon inquiry it was found 

 that in those bleak and humid situations tlie po- 



