By John Lindley, Ph. D. 



447 



the stems. Thus Lankman's Potatoe, a tall sort raised some years 

 since in Flanders, was planted in rows four feet apart, with its 

 tubers six inches from centre to centre : and it yielded 18 tons, 

 14 cwt, 70 lbs. on an acre of ground. 



On the other hand the Ash-leaved Kidney Potatoe in which the 

 stems are very short was planted in rows two feet apart, with its 

 tubers nearly in contact with each other; it yielded 24 tons, 6 

 cwt, 98 lbs. per acre. An amount of produce really enormous if 

 compared with ordinary crops which do not usually average more 

 than 10 or 11 tons an acre. 



In his next communication Mr. Knight further illustrated his 

 method by such practical remarks as experience had continued to 

 suggest. Finding that destroying the blossoms of potatoe plants 

 increased the quantity of their tubers, he inferred that sorts which 

 do not blossom are more productive than others, and accordingly 

 recommended such kinds to be cultivated in preference. He men- 

 tioned that those varieties which vegetate earliest afford the largest 

 produce, but do not keep so well as less excitable sorts ; he ad- 

 vised that varieties with stiff stems capable of sustaining their leaves 

 in a proper position should always be selected; he explained the 

 method of raising seedling Potatoes, and he reported the result of 

 his method in a high and cold situation where the ground was not 

 rich to be, 22 tons, 8 cwt, 64 lbs. of Lankman's Potatoe per acre. 



In his last communication, Mr. Knight explains the probable 

 cause of failure in obtaining crops corresponding in magnitude with 

 his own, by the fact that exhausted varieties are too often culti- 

 vated: it appears from his experiments that old varieties gradually 

 become unproductive; and that vigorous seedlings with very 

 early habits will yield the largest crops. As much as 34 tons, 

 8 cwt, 107 lbs. are mentioned as the produce per acre of such a 

 kind, and he gives it as bis opinion that more than 1000 bushels, 

 or nearly 36 tons, may and will be obtained from an acre of ground. 



