190 fnjiiienee of Seed Weight, etc. on the Potato Crop 



significance, and one is tempted to sec in this reduced yield a confirmation 

 of the conclusions reached by Middieton* that in general, cut sets were 

 inferior in cropping capacity to whole tubers. 



As in 1920, so again in 1921, the realised crops from each class were 

 analysed in the following manner: 



A ]() lb. sample was weighed out on a spring balance and was then 

 sorted into the following classes: 



Tubers weighing 



It was found that when this subdivision was made and the individual 

 groups summated, they always came to a figure within a little of lOi lbs., 

 the excess being due to error of the balance in weighing small lots. It is 

 for this reason that the relative proportion of the different classes sliown 

 in Figs. 3 and 4 is calculated to lOj lbs. It should be realised that in 

 each of these classes into which the crop has been subdivided, the tubers 

 are practically of exactly equal weight and size. The actual figures are 

 given in Schedule II. 



Although in all the sani])les, division into all the 1 7 classes was carried 

 out — as far as the material in each case allowed — it was found that for 

 practical purposes it was better to re-group the findings into four classes: 



1. Tubers of 3-33 ozs. and over. 



2. ,, over 2 ozs. and under 3-33 ozs. 



3. ,, „ I oz. „ 2 ozs. 



4. ,, under 1 oz. 



As regards classes B, C, D and G, the mean value of each weight 

 group in the crop was readily determined, always, however, taking the 

 mean of the determination where two examples of a class occurred in 

 one and the same of the four rows in the experimental plot. 



In regard to A, E and F. the same method in determining the mean 



' Middleton, T. H. Guide. In K.r/ierinnnis conilurlcd nl liiiiyni/iic's Fartn, etc, (amb. 

 Univ. Dept. (if Agriciilliiri', I'.KIT. 



