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CLOVER-SICKNESS. 
infestation in otherwise clean fields may thus be easily accounted for. 
The spread of attack from one of these may be prevented by digging 
a trench a foot or two deep round the infested area. 
As a measure of direct remedy , the application of sulphates of various 
kinds has been found to be attended with great success. 
In 1887, Mr. John Elder, of Uphall, Linlithgowshire, who has 
devoted careful attention to effect of treatment on Eelworm-attacked 
crops, applied as a dressing to “stem-sick” Clover a mixture of 
sulphate of ammonia, 4 parts; sulphate of potash, 1 part; steamed 
bones, 2 parts; this was given at the rate of If cwt. of the mixture 
per acre. This was followed up by a dressing of 2 cwt. per acre of 
sulphate of ammonia, and the result gave so luxuriant a growth that 
in little more than a fortnight after the second dressing the unhealthy 
plants (if any remained) had ceased to be noticeable. 
In the treatment of the attack of stem-sick Clover at Rothamstead, 
of which the identification is given at p. 5, sulphate of ammonia and 
sulphate of potash applied together, and also sulphate of iron as a 
dressing without mixture, were found to be very useful. 
The following is a copy of the report of the above experiments with 
which I was favoured, sent me from Harpenden on May 14th, 1889, 
by Mr. John J. Willis :— 
“ On April 3rd, two measured portions of the field were taken, each 
of which contained many affected plants of Clover, and the disease 
appeared to be spreading. To these the following manures were 
applied as a top-dressing in quantities per acre :— 
“ No. 1. Sulphate of iron, 2 cwt. 
“ No. 2. Sulphate of potash, 3 cwt.; sulphate of ammonia, 1 cwt. 
“ No. 3. On April 4tli, to another portion of the same field was 
applied 1 cwt. sulphate of iron per acre. 
“ No. 4. On April 30th, over the whole of the worst-affected part 
of the field (viz., the strip of land previously referred to, which had 
received the fish-manure in 1888) a dressing of 1 cwt. sulphate of iron, 
1 cwt. sulphate of potash, and 1 cwt. sulphate of ammonia per acre 
were applied. This mixture was sown so as to overlap the diseased 
and the healthy portions. 
“ The plants which I now send were collected this day (May 14th)- 
from the junction of the diseased and the healthy portions of the field. 
“ On experiment No. 1 and No. 2 the disease has entirely ceased, 
and the Clover is growing most vigorously; No. 2 seems the most 
effectual, and the Clover on this plot has made the most growth; not 
a blank is now to be seen. No. 3 has been less effectual than No. 1 in 
stopping the spread of Tylenchus. 
“ I send the plants from the edge of No. 4 for your opinion upon 
their condition. 
