177 



at Svalof. Here each sort occupies from two to four different plots which 

 are alternated with some standard sort such as Magnum Bonum, as a check. 

 Formerly each plot occupied 25 Kvm. (269 sq. ft.), but this was later reduced 

 to 12.5 Kvm. (134.5 sq. ft.) on account of the difficulty of finding soil of 

 sufficiently even quality over so large an area. Each plot of the area indi- 

 cated accommodates nine rows of five hills each making 45 hills in all. The 

 nine rows are 0.60 m. (23.6") apart while the hills are .45 m. (17. 7") apart 

 in the row. All sorts which seem promising are included in the above com- 

 parative trials as soon as possible. 



Some idea of the division and extent of the work with potatoes is afforded 

 by the following table, which gives the identity and exact number of the 

 different cultures operated with during the years 1904-1911 inclusive: 



Potato Work at Svalof from 1904-1911 inclusive (24 p. 216). 



In view of the ease with which the potato is affected by the character /, om ; sor i 

 of the soil in which it grows, local trials of different sorts have been con- trials. 

 ducted on rather an extensive scale. The locations for these trials have 

 been very carefully chosen so that the main types of soil where potatoes 

 can be grown at all successfully have been occupied. Thus, trial plots have 

 been placed on the sand tract which extends from Landskrana towards 

 Vombsjo south of Svalof a-nd on glacial clay soils, rich in humus and in good 

 culture lying north of Svalof. The soil at Svalof itself is, as previously 

 explained, a rather light, sharp clay loam. The above trials have not only 

 proven useful in connection with the regular work, but have revealed many 

 interesting and valuable peculiarities of the potato plant. They have 

 shown, for example, that under certain conditions the yields may be greater 

 than under others, while at the same time the starch may be lower. Thus 

 at Boketofta the starch content of tubers has been found to be almost uni- 

 versally lower than at Svalof, although the yield is usually higher. From 

 this it is inferred that the internal development of the Boketofta grown tubers 

 is not so far advanced or perfect as in the case of tubers grown at Svalof 

 despite the superiority in size of the former. 



A noteworthy exception of the above case was afforded during the cold 

 wet year of 1907, when the yields at Boketofta were much more seriously 



