70 



Problems in Potato Growing. 



[may, 



trials, and this superiority — which in itself needs to be further 

 tested — can hardly be due to greater immaturity, if that charac- 

 teristic be attributable to growth in a colder climate, unless all the 

 Scottish seed came from the south of Scotland, and all the Irish 

 seed from the north of that country, which is improbable. If Irish 

 seed generally be really less mature than Scottish seed, it must 

 be so in consequence of the greater dampness of the Irish climate, 

 and not on account of greater coldness. 



But, as a matter of fact, is Scottish seed less mature than 

 English, and is Irish seed less mature than Scottish ? The 

 question should be answerable by the careful examination of a 

 number of samples. So far as premature sprouting may be 

 regarded as a test of immaturity, my own experience is that 

 seed grown on my farm, and taken from a crop raised just after 

 the skins of the tubers were fully set, was much less mature 

 than seed obtained from Scotland, and yet the latter gave a much 

 greater yield in several trials. 



The best test of the point at issue yet made public was carried 

 out for the University of Leeds and the Yorkshire Council for 

 Agricultural Education last season. Seed from portions of a 

 crop raised when the haulm was quite green and the skin of the 

 tubers tender in 1905 was tried in 1906 against seed from portions 

 of the same crop raised after the tops were quite dead and the 

 skin of the potatoes had become tough. The yields of two 

 varieties of boxed mature seed were 12 tons 10 cwts. and 11 tons 

 11 cwts. per acre respectively, while those of boxed immature 

 seed of the same varieties were 11 tons 5 cwts. 3 qrs. and 11 tons 

 14 cwts. Again, unsprouted mature seed of one of the two varie- 

 ties yielded 10 tons 12 cwts. 1 qr., against 9 tons 2 cwts. 1 qr. 

 obtained from unsprouted immature seed. In a similar trial 

 carried out in the preceding season, whole sets of two varieties 

 showed an advantage to immature seed and one variety a dis- 

 advantage ; while with cut sets two results out of three were in 

 favour of mature seed. 



Potato Scab. — The report giving these results also describes the 

 results of experiments for the prevention of scab in potatoes, a 

 problem requiring further elucidation. It had been noted that the 

 disease was more prevalent in light than in heavy soils and in dry 

 than in wet seasons. Therefore, various substances which tend to 

 increase the water-holding capacity of a soil were applied to land 



