283 JOUfiNAL OF THE EOYAL HOETICULTUEAL SOCIETY. 
Minister School Farm. 
Covered ground. 
Sound tubers . . 95 
Diseased . . . nil. 
Uncovered ground. 
Sound tubers . . 76 
Diseased . . . 15 
If the soil is not thoroughly stirred and the drills loose, with plenty of 
soil on the top, the tubers will when expanding force their way to the 
surface, in the direction of leasb resistance, and many of the tubers 
will be exposed to the lighl. and become green or sunburnt, and thus 
unmarketable except for seed. 
Organic matter in a soil is of the greatest importance, because it helps 
to conserve moisture and thus supplies the plants with water ; it also 
keeps soils free and open and prevents them from becoming hard and 
unworkable. In a wet season it promotes drainage. 
We will now take up the results obtained from the experiments at 
Holmes Chapel. The first portion of the work consisted in testing nearly 
all the new varieties introduced, in oi-der to ascertain the yield and main 
characters of each variety. This experiment is carried out with each 
variety for three years, in plots 21 yards long by | yard wide. Those 
varieties which are promising are then S3lected and planted on another 
set of plots one-twentieth of an acre in size, and the next year they are 
planted on larger plots half an acre in area: by this method we can 
thoroughly test each variety, and we find they vary very much in yield. 
This year the minimum yield on the small plots from 7 lb. of seed in 
the case of Second Early Rounds was 40 lb., the maximum yield on the 
same sized plot with another variety being 194 lb., or almost five times 
this yield. 
In the case of First Early Kidneys, the heaviest yield was 133 lb., and 
the smallest was 22 lb., or only one-sixth of the yield. This shows 
clearly the vast difference in yield in different varieties. 
The second point was to test whole sets versus cut sets. This is a 
question which has caused a considerable amount of controversy ; and even 
yet we find people who are not decided about which is the better to plant. 
In some districts in the United Kingdom only cut sets are ever planted ; 
in other districts we find nothing but whole sets planted. It would be 
quite an easy matter to prove that cut sets are better, and equally as easy 
to prove the opposite. It depends upon several conditions : — 
1. The variety of potato. White-blossomed varieties are usually soft 
and much more easily injured, and therefore likely to miss when cut ; but 
coloured-blossomed varieties stand cutting well. 
2. Varieties which produce usually only one or two sprouts, that is 
haulms, are much more liable to miss than those which produce many 
sprouts or haulms. 
3. If the sets are cut thin and weak from small tubers they will only 
produce puny buds and stunted plants, and if not very carefully treated 
