44 Influence of Size of Seed on Yiet.d of Potatoes. [Apr., 



distance between the sets was 15 in. and between rows 30 in. 

 Tubers were not cut. 



It is realised that in order to obtain reliable and accurate 

 results in respect to cropping, it is rightly accepted that each plot 

 should be repeated several times and the probable error calcu- 

 lated; this has not been done. Notwithstanding, there is evi- 

 dence that a very considerable degree of accuracy may be 

 ascribed to the results obtained. Thus when the ware sized 

 tubers were used as seed, Classes 5-7, the resulting crops are 

 12.0, 11.2, 11.8 tons per acre respectively, which is not 

 only a closely similar result, but one which previous experience 

 would suggest. The very striking similarity between the average 

 of the analysed results of the eight crops with that derived from 

 mixed unselected seed of the same variety (Table IT), would 

 further suggest that the crops as shown in each of the eight 

 classes cannot vary much from their true modes. Without 

 therefore, wishing to stress unduly the results arrived at, the 

 writer feels considerable confidence that the outstanding features 

 which will be shortly detailed may be accepted as a general 

 guide to the solution of the problem in hand. 



In Table I the actual weight and number of seed of each of the 

 eight classes employed are shown. In addition the weight of 

 the crop returned; the ratio of yield to seed v/eight; the yield 

 per acre ; the weight of seed used per acre ; the weight of ware 

 tubers of 4 oz. weight and over, and the net crop after deducting 

 the weight of seed used are shown. ^ 



TABLE I. 





73 













o 







CD 









lass of Se( 

 Tuber. 



Weight of 

 Set. 



Weight of 

 Seed Used 



Number o 

 Sets. 



Weight of 

 Yield. 





atio Seed i 

 Yield. 



Yield per 

 Set. 



Yield per 

 Acre. 



O . 



f. « 



are per Ac 

 oz. and ov 



eld per Ac 

 less Seed. 















Pi 







$ 











oz. 



lb. 





lb. 







lb. 



tons 



tons 



tons 



tons 



1. 



36:11b. ... 



•44 



8-5 



304 



280 



1 



33 



•92 



5-7 



•17 



2-15 



553 



2. 



12:11b. ... 



1-33 



29 



348 



504 



1 



17-4 



1-45 



9-0 



•51 



2^45 



8^49 



i'. 



12:Ulb. ... 



2- 



3] 



248 



553 



1 



18 



2-23 



13-8 



•77 



436 



130 



4. 



12:21b. ... 



2-66 



73 



438 



756 



1 



10-3 



1-73 



10-7 



1- 



3^67 



9-7 



5. 



12:3 1b. ... 



4- 



16-5 



66 



128 



1 



7-8 



1-95 



12-0 



1-5 



2-64 



10^5 



6. 



12:4 1b. ... 



5-33 



47-5 



142 



256 



1 



5-4 



1-8 



11-2 



2-1 



3-55 



9-1 



7. 

 8. 



12 : 411b, 

 12 : 41 lb. ) 



5-66 



50 



141 



264 



1 



5-3 



1-9 



11-8 



2-2 



2^82 



9^6 





Secondary / 

 growths ) 



6- 



20 



53 



123 



1 



6-1 



2-35 



14-6 



2. 



8^8 



12-2 



























From this table two facts are evident : — (1) That it is tubers of 

 2 oz. weight which give the best return of crop, excepting the 

 large tuber sets with secondary growths. When, however, the 



