191 1.] Experiments in Potato Growing. 



897 



heavier than that from the Scotch seed, and in other years the 

 reverse. Two experiments, one in 1908 and the other in 

 1910, tend to prove that seed from the west, north-west, 

 and south-west parts of Ireland is distinctly better and pro- 

 duces heavier crops than seed obtained from the east side of 

 that country. 



A potato grower then, in the east of England, may reason- 

 ably expect an increased yield of potatoes of from 2-3 tons 

 per acre if he changes his seed every two years, and he will 

 be equally safe in purchasing his stocks either from Ireland 

 or Scotland, provided fie uses his judgment in making in- 

 quiries beforehand. 



Size of Sets, — The effect of the size of sets has been tested 

 on the University Farm for four years, with the result that 

 medium sets about ij- to if in. in diameter would seem to 

 be the best. Such sets will weigh from 15 cwt. to 18 cwt. 

 per acre, if planted 14 in. apart in 28-in. rows. 



The following figures give the results of the first of these 

 trials in 1905. The variety was Factor. 



Weight 













planted. 



Total crop. 



Ware. 



Diseased. 



Cwt. 



Tons. 



Cwt. 



Tons. 



Cwt. 



Tons. Cwt. 



iof 



9 



15 



6 



4 



I 4 



1 6i 



10 



IO 



6 



13 



I 8 





11 



17 



6 



12 



2 7 



56 



13 



14 



6 



8 



2 12 



Sets between \\ and \\ ins 



„ i\ and if ... 



if and 2 ... 

 2 J ins. and over 



Two interesting points may be noticed in this experiment. 

 The large sets produced a relatively low percentage of ware, 

 and they also seemed to produce a high percentage of 

 diseased tubers. The prevalence of disease where larger sets 

 are used is associated with the more luxuriant haulm. 



In the later experiments of 1906 and 1907 the effect of 

 large sets on the percentage of ware was again noticeable, 

 the following figures showing the averages obtained from 

 three sets of plots in each year. These represent a total of 

 tw T enty-four plots. 



Sets between i\ and if ins. 

 „ if and 2| 



Weight 

 planted. 

 Cwt. 

 18 



37 



Total crop. 

 Tons. Cwt. 



11 O 



12 3 



Ware. 

 Tons. Cwt. 



8 8 

 8 11 



The most noticeable thing here is the extra weight of 

 potatoes planted, amounting to practically 20 cwt. per acre, 

 giving as increase only 3 cwt. per acre of ware or marketable 



3 R 



