234; Cause of Curl in Potatoes, 



tained in a ripe and in an unripe tuber ; the former is preferred, 

 while the latter is rejected, by the parent insect. It is now 

 confirmed by experience, and has become a rule in practice, 

 to prefer unripe sets to fully ripe ones, as a preventive where 

 the curl is dreaded; and this, I can aver, it has constantly 

 proved in my own practice, and therefore I can confidently 

 recommend its adoption to every cultivator of the potato. 



Besides being a security against the curl, the use of unripe 

 sets has, as I mentioned in a former letter, an advantage of 

 incalculable value to all who either cultivate potatoes, or to 

 •whom they are a necessary of life. To the cottager, to the 

 serving or commercial gardener, and to the agriculturist, the 

 obtaining of a crop a month or six weeks earlier is a result of 

 great importance, and, one would think, only requires to be 

 known, to be universally followed. 



At some future opportunity I shall beg to trouble you with 

 some observations on the culture of the strawberry, which may 

 not, I flatter myself, be unworthy of the attention of your 

 readers. I am. Sir, &c. 



April 10. 1S28. A Denbighshire Gardener. 



Note by Mr. Main. — It is now near forty years since it 

 was discovered, that a waxy set of a partly ripe potato was 

 less liable to curl than a mealy one. This fact pointed out 

 the propriety of obtaining sets from bleak or moorland dis- 

 tricts, where it is necessary to take up the crop before the tubers 

 are thoroughly ripened. This change of seed, as they are 

 called, being attended with success, suggested the idea, and 

 induced the expedient, of taking up the potatoes intended for 

 the next year's sets before they were ripe, and hardening them 

 by exposure to the sun and air, to fit them to be stored safely. 

 Many conflicting opinions have been stated respecting the 

 cause of the curl, as well as on the rationality of the means 

 taken to prevent it. Mr. Knight deems the property of meali- 

 ness an over-maturity of the plant, and therefore seems to 

 conclude, that a perfectly healthy plant can hardly be expected 

 from a mealy set. Others, with much more reason, have 

 supposed the curl to be an endemical attack, happening in any 

 district a certain number of years after the introduction of the 

 potato, from neglecting to change the kind, or from some at- 

 mospherical influence not easily accounted for. The history 

 of the plant shows that the curl is only a local and temporary 

 disease ; and many districts formerly subject to it, as the 

 neighbourhood of London, for instance, are now free from its 

 ravages, without any care in preparing the sets, or other pre- 

 caution, save only in an occasional change of seed-sets. If, 



