NOTES ON SCIENTIFIC RESEARCH. 65 - 
Celery suffers from various fungus diseases. One of the most troublesome, known 
as “celery leaf scorch” or “celery rust’, is caused by Septoria Petroselini var. Apii 
(Sphaerioideaceae). It appears first in the form of small scattered pale green spots, 
subsequently increasing in size until the leaf is covered, which then turns brown, 
curls up and withers; in this state the disease is called “celery blight”. Finally, the 
perithecia appear as tiny black spots. If discovered in an early stage, the disease 
may be subdued with potash sulphide; all the foliage with perithecia should be burnt. 
Another disease, known as “‘celery leaf rot”, is due to Sclerotinia sclerotiorum, Mass. 
It attacks the roots and causes the heart of the plant to become pulpy, and ultimately 
kills the plant. As this fungus passes through the winter in the sclerotia stage, all 
dead portions of the celery should be burnt where the disease is prevalent. Puccinia 
bullata, Winter, also occurs on celery, as well as on dill and parsley, but is not 
serious unless. present in quantity. 
A disease attacks seedling cloves, and will also kill trees 12 to 14 feet high, but 
it has not been thoroughly investigated. The fungus causing it apparently belongs to 
the Peronospora group. There is also a disease attacking the rhizomes of the ginger 
plant, but it has not as yet been accurately described. 
The leaves of Iris and Freesia species are subject to the attacks of Heterosporium 
gracile, Sacc. (Dematiaceae). The leaves wither early and die. Puccinia iridis, DC., is 
likewise pernicious on iris. Mystrosporiwm adustum, Mass. (Dematiaceae) destroys some- 
times the bulbs of Jris reticulata. It is said that soaking the bulbs for two hours in 
a solution of 1 part of formalin in 300 parts of water will kill the fungus without 
injuring the bulb. The disease is styled “iris bulb scab”. “Iris rot” is due to Bacillus 
omnivorus, Pseudomonas viridis, P. fluorescens and P. exitiosus. The portion immediately 
below the ground becomes soft and rotten, and the disease often extends to the 
rhizomes and the offshoots. The presence of the disease is indicated by the wilting 
of the leaves, which soon become yellow and die. As soon as this is the case, the 
plants must be dug out and burnt. Superphosphate of lime is said to check the 
disease, whilst quicklime favours its development. 
The roots of the juniper shrubs are destroyed by “conifer root rot” (Fomes 
annosus, Fries, Polyporaceae), whereas Gymnosporangium juniperinum, Wint. (Pucciniaceae), 
grows exuberantly on the stem and the branches. The aecidia of the fungus grow on 
the mountain ash. Juniper is likewise attacked by G. clavariaeforme, Jacq. (aecidia on 
hawthorn and Sorbus Aria), and G. Sabinae, Wint. (aecidia on pear tree leaves). The 
latter also lives on Juniperus Oxycedrus, L., J. virginiana, L., and J. phoenicea, L. The | 
removal of the host plants from the near neighbourhood of juniper will stop the disease. 
Keithia tetraspora, Sacc. (Phacidiaceae), is also found on juniper needles, but it has not 
been regarded as a Serious pest. 
The lemon and orange trees are exposed to several fungus diseases. Colletotrichum 
gloeosporioides, Penzig (Melanconiaceae), causes a destructive disease on lemon, lime 
and orange trees. The tips and edges of young leaves are first attacked, becoming 
light green, and eventually brown, or nearly black, little heaps of spores being formed 
on both sides of the leaf. The leaf withers and the young shoots shrivel. The blossoms 
are also attacked and the young fruits then fall very easily, so that often no single 
fruit remains on the tree. Fruits can be infected if their surface is abraded, when the 
disease often develops after they have been shipped. They then are of no value at all. 
It has been recommended to wash the fruit after gathering with potassium. sulphide 
or ammoniacal solution of copper carbonate. Possibly formaldehyde would be better 
on account of its leaving no deposit. All diseased twigs and leaves should be burnt. 
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