292 
JOUEXAL OF THE ROYAL HORTICULTURAL SOCIETY. 
These were carried out in duplicate plots. 
Artificial manures produced a heavier yield than no manure. In the 
case of ' British Queen ' the crop was more than doubled, giving an actual 
increase of 7 tons 1 cwt., valued at *'18. 4.s. 3J. per acre. In the case of 
' Hough Giants,' the increase was not so great, being 8 tons 1;^ cwt., 
valued at i."7. 8s. Gd. per acre. 
The artificial manures produced a much stronger haulm and broader 
leaves of a dark green colour. The potatos ripened later, and the per- 
centage of saleable tubers showed an increase of 4*6 per cent., while the 
percentage of small was proportionately reduced. The saleable potatos 
were larger where artificial manures were applied. 
Farmyard manure gave a heavier yield than no manure in both 
varieties tried. In the case of ' British Queen,' the total yield was increased 
by 9 tons 18^ cwt. per acre : of this increase 9 tons 12 cwt. were sale- 
able potatos, the net gain being £24. 14.s. per acre. In the case of 
' Hough Giants ' the increase was 7 tons 10 cwt., valued at * 16. Is. 
per acre. 
On no-manure plots the haulms were short and the leaves small and 
crumpled, so much so that the general character of the foliage was quite 
difterent from that of those growing on the farmyard manure plots 
adjoining; nearly every person who saw these plots thought that those 
potatos which received no manure were a different variety. The potatos 
also ripened fully a month earher than those which received farmyard 
manure. 
On farmyard-manure plots the haulms were very strong, the leaves 
broad and of a dark green colour. The saleable potatos on no-manure 
plots were nearly all seconds or seed size, small undeveloped tubers, 
whereas those on the farmyard-manure plots were much larger. 
The application of farmyard manure increased the percentage of 
saleable potatos by 10-3 per cent., and reduced the percentage of small 
accordingly. Xo-manure plot had the lowest percentage of saleable 
potatos. 
Farmyard Manure versus Artificial Manures. 
Farmyard manure gave a much larger yield than artificial manures. 
In the case of ' British Queen ' the increase was 2 tons 17^ cwt., leaving 
a net profit of i6. 10s. Sd. ; with ' Hough Giants ' the increase was 4 tons 
8J cwt., leaving a profit of £8. 12s. Qd. per acre. 
The eftect of farmyard manure shows clearly that the yield of crop 
does not depend entirely upon the chemical ingredients used, but that 
the mechanical condition of the soil influences the yield to a large 
extent, as in both cases the same manurial ingredients were applied. 
The farmyard manure undoubtedly made the soil more open and 
more easily worked, and at the same time it conserved moisture and 
supplied the potatos with water, and no doubt the increased yield is due 
to these properties, which artificial manures have not. 
The farmyard manure produced a stronger haulm and much larger 
tubers than the artificial manures. The percentage of saleable potatos 
was increased by .r7 per cent. 
