CONTRIBUTIONS FROM THE WISLEY LABORATORY. 6oi 



Table III. showing the Characters of Tubers planted in Pots in ordlr 



of Weight and Size. 



Tuber 

 number 



Weight in 

 grammes 



Number 

 of eyes 



Eyes 

 shallow or 

 deep 



Groupiug 



of 

 sprouts 



Sprouts 

 injured 

 or not 



Number of 

 sprouts 

 removed 



Situation of 

 sprout left 



Skin smooth 

 or rough 



Skin injured 

 or not 



Texture of 

 the tuber 





I 



202 



TA 



t m 1 s 



1 si 





0 



j 



j- 



1 



T 



m 





! 



I90 



II 



t m 1 s 



t si 1 si 



- 



3 



t 



r 



+ 



m 







I95 



9 



t m 1 s 



1 si 





3 



1 

 1 



r 



+ 



m 



CO > 



\ 



S5 



10 



tm 1 m 



.". ... 





J 





r 





f 



a * 



5 



83 



5 



tm 1 m 



tgr 







t 



r 



+ 



f 





6 



86 



7 



tm 1 m 



... 1 si 





0 



1 



r 





m 



7 



50 



8 



t m 1 s 



tsi ... 





0 



t 



m 





f 



in £ T3 



8 



56 



8 



tralm 



tsi ... 





2 



t 



m 



+ 



f 



- O +j 



CO 1- £ 



9 

 10 



5i 



39 



6 

 7 



t m 1 s 

 t m 1 s 



tsi ... 

 tsi ... 





I 



0 



t 

 t 



m 

 r 



+ 



f 

 f 



S. 1 



ten : 

 pla 



11 



38 



6 



tmlm 



tsi ... 





0 



t 



r 





m 



*I 



12 



37 



6 



tm 1 m 



tsi ... 





0 



t 



sm 





i 





13 



3i 



6 



tmlm 



tsi ... 



+ 



0 



I 



r 



+ 



so 



CO 



>- CO 



14 



26 



7 



tmlm 



t si 1 si 





2 





sm 





m 



Tub 

 piec< 



15 



25 



7 



tmlm 



tsi ... 





O 



t 



m 





f 



d = deep f = firm gr = groups 1 = lateral m = medium r = rough 

 s = shallow si = single sm = smooth so = Soft t = terminal 

 -f = injured — = not injured. 

 Numbers printed in heavy type indicate that the tubers in question produced 

 bad plants. 



resembled that of the bad plants grown in the open (see section A). 

 By May 2 only five plants remained with green uninjured foliage — 

 tuber numbers 1, 2, 3, 4, and 6, Table III. — originating from the 

 heaviest sets by weight. In fact, all the tubers, with one exception, 

 above 80 grammes by weight produced good plants, all below 60 

 grammes by weight bad plants. 



D. — Relation between Soil and Leaf -blotch. 



Experiments were made to ascertain the effect of planting sound 

 tubers in soils from different localities — the " climatic " conditions 

 being constant. 



This experiment was commenced early in February in order that 

 it might be possible to exhibit some of the plants raised at the Inter- 

 national Horticultural Exhibition held in May 1912. It was, of 

 necessity, on a small scale, owing to the difficulty of obtaining quantities 

 of imported soil. 



The soils chosen and actually used were as follows : 



1. Sandy soil from the R.H.S. Gardens, Wisley, not previously 

 used for potatos. 



2. Reddish loam from the Dunbar potato fields ; a small percentage 

 of bad plants was produced, at Dunbar, in this soil, in 1910. 



3. A light-coloured clay from the experimental grounds of the 

 S.E. Agricultural College, Wye; bad plants were produced on this 

 soil in 1911. 



