114 Cultivation of Arable Land. Potatoes. Dtfeafes of. Curl. 



And as it has been found that the produce of fuch potatoes as have been once 

 effected with the curl will, when planted on the fame land, uniformly continue to 

 afford curling plants, a change of the feed of the potatoe may in all fituations be 

 more effentially requifite than that of moft other forts of crops. 



It has likewife been remarked, that on taking up the potatoes in a field that had 

 been partly planted with fuch feed as had been produced on the land, and partly 

 by that from a colder climate, and confequently a later, that the produce in the 

 former cafe was at leafl in the proportion of three to one lefs than in the latter.* 



In the idea that the difeafe is produced by the devouring attacks of infects on 

 the fets, it feems not improbable but that advantage might alfo be derived from 

 the impregnation of them with fuch liquid fubflances as they are found to avoid, 

 or which are noxious to them, in the way of fteeps. In performing this, great 

 care mould, however, be taken that fuch materials be not employed as have a 

 tendency to injure their vegetative quality. 



Befides thefe, it may be of great utility in guarding againft the difeafe to be 

 particularly attentive to the preparation of the ground, the proper feafon of plant 

 ing according to the nature and fituation of the land, and to the accurate after 

 culture of the crop; as there is reafon to fuppofe, that where thefe points are 

 either wholly neglected, or performed in an incomplete manner, the crops arc 

 more liable to be injured by the curl. f 



In Mr. Chappie s experiments, confiderable advantage feemed likewife to be 

 derived from felecting the bed and moft perfect potatoes for feed, from fuch as 

 had been grown upon a piece of ground fet apart for the purpofe at a diftance from, 

 the others, and during the after-culture of the crop picking out the difeafed 

 plants. J 



It has alfo been lately fuggefted, that by ufing the dark-brown coloured ex- 

 crefcence that grows to the fize of a large horfe-bcan on the haulm orftraw of the 

 potatoe near to the ground, or what is termed ira fome places potatoe bean t for 

 feed, the curl may be prevented. Thefe beans have the form of the potatoe, and 

 prefent a number of eyes, from one of which two fmall leaves generally iffue. 



In an experiment made with thefe, in order to afcertain their vegetative pro 

 perty, it was found that they produced a large number of potatoes of the or 

 dinary fize, but of inferior quality. Thefe, however, on being cut and planted 

 the following year, afforded potatoes of an excellent quality, and in great abun 

 dance. Encouraged by thefe trials, a fufficient proportion of this fort of fets has 

 been annually collected and planted for the purpofe of fupplying feed for the en- 



* Farmer s Magazine, vol. III. and Bath Papers. 



f- Communications to the Board of Agriculture, vol. II. \ Bath Papers. 



