i9i i.] Experiments in Potato Growing. 



895 



possible way. Where fresh stock of Up-to-Date, British 

 Queen, and Northern Star were compared with worn-out 

 strains, we obtained respectively 9-J, io|, 12J tons increase, 

 and where a stock of Factor, which had been on the farm in 

 seasons 1903 and 1904, was compared with produce of sets 

 purchased in the Lothians in the spring of 1905, the fresh 

 seed produced an increase of five tons. But the most instruc- 

 tive figures in the above table are those contained in the 

 last lines. In the spring of 1904 potatoes which had been 

 grown in Cambridge in 1902 and 1903 were sent to be 

 planted on a light loam soil at Field Dalling, near the north 

 coast of Norfolk, in a district in which many potatoes are 

 not grown, and at the same time another lot was sent to 

 Cromarty, on the north-east coast of Scotland, to be grown 

 on a loamy red sandstone soil specially adapted for the 

 production of vigorous potato crops. From both districts 

 sets were sent back to Cambridge in the spring of 1905, and 

 planted side by side with the original stock. It was found 

 that in neither case did the potato plant benefit markedly 

 from the change. The contrast between the crop grown 

 from Lothian seed that had not previously been in the 

 south, and the crop that had been but one year in the 

 north of Scotland, was very striking throughout the grow- 

 ing season. 



In 1906 experiments on change of seed occupied 56 plots, 

 and a great deal of useful information was obtained. The 

 chief experiment was on the effect of climate on Up-to-Date 

 seed obtained from the north-east and south-west of Scot- 

 land, the north of Ireland, North Wales, and from Kent. In 

 all these cases the seed had been grown for at least two years 

 in the district from which it came. 



The following results were obtained : — 



Total 

 crop. 



Variety. Tons. Cwt. 



Up-to-Date. Grown in Cambridge for at least five years ... 7 3 

 ,, one year, previously in 



Cromarty ... ... ... ... ••• *4 12 



Grown in Cromarty for six years 16 19 



Dumfries for two years 16 o 



,, Co. Tyrone for two years 15 18 



,, Carnarvon for four years 9 1 3 



,, Kent for two years ... ... ... 8 4 



Similar results to the foregoing were got from Northern 



