C 156 ] 



XX HI. An Account of some further Experiments, made in the 

 Garden of the Society, in the year 1836, relative to the Cultiva- 

 tion of Potatoes. By Mr. Robert Thompson Under Gardener 

 in the Fruit Department. 



Read December 6, 1836. 



The results of various experiments upon this subject having 

 been already published in the Transactions, it will be proper 

 briefly to refer to them on this occasion. 



In the year 1831, experiments were made with the view of 

 ascertaining the effect of planting the sets of Potatoes much wider 

 apart than usual, in order to give the foliage a greater exposure to 

 light. Whole tubers were accordingly planted in spaces containing 

 16 square feet. The result was, that strong growing sorts, including 

 a number of Mr. Knight's seedlings, produced fully an average, 

 whilst a few gave a very great crop. But although one of the 

 latter produced at the rate of 21 1. 13 cwt. 59 lb., a weak growing 

 sort produced only 1 1. 5 cwt. 92 lb. The vigorous could avail 

 themselves of their ample space, which they occupied with their 

 stems and foliage to the full extent ; the weaker could not. Hence 

 the propriety of suiting the distance of planting to the vigour of 

 the sort.* 



In the year 1832, experiments were made with regard to the 

 relative produce of sets from whole tubers, and from single eyes. 

 The result was in favour of the latter by upwards of 7 cwt. 

 per acre, and considerably more on comparison of the clear produce 

 after deducting the weight of sets employed in both cases, f 



* See Transactions, Vol. I. Second Series, p. 153. 

 f See Transactions, Vol. I. Second Series, p. 445. 



