CELERY AT WISLEY, 1916. 
IO9 
CELERY AT WISLEY, 1916. 
Fifty stocks of Celery were included in the trial of Celery in 1916. 
The seed was all sown on March 20 in pots under glass ; the seedlings 
were pricked out into boxes on April 11, and transplanted into the 
trenches on June 6. The ground had been occupied partly by early- 
flowering chrysanthemums, partly by winter greens in 191 5 ; it was 
not dug, but trenches about 12 inches wide and 6 feet apart were 
taken out ; into each trench (36 feet in length) two wheelbarrow 
loads of manure were worked. The plants were set out in a single 
row 9 inches from plant to plant, and made very good progress 
until the last week in August, when the Celery leaf -spot disease (due 
to the fungus Septoria Petroselini var. Apii, see Journal R.H.S., 
vol. xxxvii. p. 115, and xl. p. 476) made, its appearance in three 
varieties and quickly spread to others. The three varieties, which 
were very badly attacked, viz. Nos. 21, 22, and 33, were dug up and 
burned, and are not described below. Curiously enough, they were all 
varieties which had received awards in previous trials, seed of which 
had been purchased for comparison with newer varieties. 
The seed sent in was examined when received, and as it was found 
in several cases to be infected with the fungus above referred to, it 
was treated by steeping for two hours in a solution of hydrogen per- 
oxide (20 vols.) ; some of the Celeriac seed also was found to be in- 
fected, and this too was steeped. The seed was subsequently dried 
before sowing, and in no case was the germination adversely affected. 
Unfortunately, at the time of the treatment, hydrogen peroxide was 
difficult to get and probably some used was less good than the rest, 
which may account for the outbreak in the three varieties mentioned. 
There is no doubt that the handling in removing side shoots pre- 
paratory to earthing up and the like assisted in the spread of the 
fungus, which imposed a serious check upon the plants. Its progress 
was stopped by spraying on four occasions with Burgundy mixture, 
different strengths as follows being used on different dates : 
Sept. 1. — Copper sulphate, 1 J lb. ; washing-soda, 1^ lb. ; soap-powder, 25 oz. ; 
water, 50 gallons. 
,, 7. — Copper sulphate. i| lb. ; washing-soda, if lb. ; soap-powder, 25 oz. ; 
water, 50 gallons. 
14. — Copper sulphate, i| lb.; washing-soda, 2 lb.; soap-powder, 25 oz. ; 
water, 50 gallons. 
» S°- — Copper sulphate, 2 lb.; washing-soda, 2 Jib. ; soap-powder, 25 oz. ; 
water, 50 gallons. 
Owing to the check imposed by the disease and the heavy rain- 
fall in. October earthing up was much delayed. It was commenced 
in the first week in October, a second earthing was given in the last 
week of that month, and a final one in the third week in November, 
