8 9 4 



Experiments in Potato Growing. [fee., 



to be to put the seed into sprouting trays. It was the practice 

 to place early varieties in the "boxes" at the end of the 

 year and the main crops or later kinds about the end of 

 February. 



Change of Seed. — The source of his seed potatoes is the 

 most important point which the potato grower has to con- 

 sider. The benefits due to change are well known, but the 

 reasons for these benefits are not so clearly appreciated, and 

 very contradictory opinions are given as to the merits of 

 certain districts for seed production. Before discussing this 

 question, it will be well to examine the evidence which our 

 experiments afford on the subject of change. Our earlier 

 experiments with Scotch seed compared seed grown locally 

 for one year with seed fresh from Scotland, and in 1903, in 

 conformity with local opinion, we found that seed grown one 

 year in Cambridge was quite as good as, indeed, rather better 

 than, Scotch seed. 



In 1904 a comparison was made between seed originally 

 purchased in Scotland, which had been grown two years and 

 one year respectively in Cambridge; and again, in accord- 

 ance with the usual experience, we found that the latter gave 

 the best crop. The results were : — 



Tons. Cwt. 



Factor potatoes one year from Scotland ... ... 13 4 



,, two years ... ... 10 18 



Difference due to newer seed ... ... ... 2 6 



In the season 1905 further experiments on "change of 

 seed" were made, and the following figures were obtained 

 for four varieties : — 









Total 



Increase due 









crop. 



to change. 



Variety. 



History of seed. 





Tons. 



Cwt. 



Tons. Cwt. 



Up-to-Date. 



Five years in Cambridge ... 





4 



17 







Fresh from Cromarty 





14 



J 3 



9 16 



British Queen. 



Three years in Cambridge ... 





5 



3 







Fresh from the Lothians ... 





15 



13 



IO IO 



Northern Star. 



Three years in East Anglia 





4 



15 







Fresh from the Lothians ... 





17 



13 



12 18 



Factor. 



Three years in Cambridge ... 





10 



10 







Fresh from the Lothians ... 





15 



8 



4 18 



Factor. 



Grown in Cromarty, 1 904, 



from 











Cambridge seed ... 





11 



12 





j» 



Grown in Norfolk, 1904, 



from 











Cambridge seed ... 





9 



6 •■ 



2 6 



Here we have the benefits of change shown in the clearest 



