May, 1890. 
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the grass from under a tree that had been 
very thoroughly sprayed and subjected it to 
a chemical analysis, with the result that on 
ly .4 of a grain of poison was found. This is 
much less than a poisonous dose for any do- 
mestic animal. We therefore feel safe in 
asserting that there is not the least danger 
in pasturing an orchard immediately after 
it has been sprayed. 
Conducted bt Prof. F. Lamson Scribner, 
Botanist, Experiment Station, Knoxville, Tenn. 
Plum It ot or tlie IHonilia of Fruit. 
The Monilia, or as it is sometimes called, 
the Oidium, of fruit ( Monilia fructigena) is 
a fungus widely distributed in this country 
and is especially destructive to stone fruits, 
peaches, plums, etc., in the Middle and 
Southern States. It was particularly pre- 
valent in this vicinity last summer seriously 
injuring the peach crop. At the time when 
the peaches were ripening there were al- 
most daily showers and the weather was 
hot and sultry, conditions especially favor- 
ing the growth of the Monilia. Frequently 
the entire product of a tree was attacked 
and practically destroyed before the fruit 
was ready for harvest, and of some of the 
choicer early varieties it was often difficult 
to secure for eating a single peach whol- 
ly free from the fungus. In a single coun- 
ty in Maryland the loss of peaches in 188s 
from this rot, was estimated to be 400,- 
000 baskets or $200,000. When we con- 
sider that this parasite attacks plums 
cherries and apricots as well as peaches, the 
moneyed loss to the entire country which 
it may occasion, and which it annually 
does occasion , must be very great. With- 
out data we can make no definite estimate 
of the amount but we already know enough 
to appreciate the gravity of the disease and 
the importance of using every effort to com- 
bat it. 
The Monilia appears upon the surface of 
affected fruit as mealy or grayish white 
patches of greater or less extent, usually 
on the side most exposed to the light. Ex- 
amined closely these patches are seen to be 
made up of a number of little tufts, form- 
ing an unevenness of surface in the larger 
patches, of fungus growth. This growth 
consists for the most part of spores which 
are borne in chains or one above another on 
comparatively short stalks (see fig 267). 
which is designed to illustrate one of the 
tufts above mentioned). The mycelium of 
the fungus grows among and through the 
cells composing the tissue of the fruit, turn- 
ing them brown. Wherever this mycelium 
comes to the surface spores are formed, by 
a constriction of the mycelium threads, in 
great abundance. It would seem that the 
fungus in a single affected peach or plum 
might produce many thousand and perhaps 
millions of spores. These spores, blown 
about by the wind or washed by rain 
from fruit high up on a tree to that lower 
down, may each one of them infect healthy 
fruit. If the temperature is high and the 
spores fall in a drop of water on the surface 
of a healthy peach or plum they will quick- 
ly germinate and the germ tube will bore its 
way through the skin of the fruit, thus in- 
fecting it and rot will 
follow. If the skin of 
the fruit is broken in 
any way, infection is 
made more certain and 
rot follows more quick- 
ly. In the case of the 
apple it appears to be necessary to infection 
that the skin be previously broken. 
Fie. 267. 
The fungus lives over the winter season 
in the fruit which it has destroyed through 
the summer, and possibly also in the twigs 
of the trees as these are sometimes infested 
by it. On the first of last January, the 
weather at the time being unusually warm 
and damp, we found this fungus producing 
spores on dried peaches that were still ad- 
hering to the trees. We inserted some of 
these spores in two slight incisions, about 
two inches apart, in an apple, and at the 
same time placed some of them in a drop 
of water on the apple where the skin was 
unbroken. The apple was then placed un- 
der a bell-jar where it was kept moist. In 
two days the spores in the incisions had 
germinated and the mycelium had grown 
sufficiently to produce new spores. Two 
of these mycelial threads bearing spores are 
shown in figure 
266, an’d to the 
rv left is shown a 
single spore 
which has push- 
| Q\ed a germ-t u b e . 
On the third day 
after inoculation 
the tissue imme- 
diately about the 
,inci s i o n s had 
commenced to 
turn brown and 
within a week 
this discoloration, 
extending from 
each incision had 
met, forming one large brown “rotien” 
spot. The mycelium of the fungus was 
found throughout all the tissue between the 
points of infection. The spores planted on 
the uninjured skin failed to develop. 
In regard to the action of this Monilia on 
the twigs of the peach Mr. Erwin F. Smith, 
(in the Journal of Mycology Vol. 5. No. III.) 
says: 
“When the rot appears in the twigs it is 
commonly called ‘blight’. I first discover- 
ed this blight in the summer of 1887, in Del- 
aware, where it was unusually prevalent. 
Trees thus attacked present a very peculiar 
appearance, quite suggestive of blight in the 
apple and pear, only in the peach the des- 
truction appears to be confined principally 
to the twigs, the injury seldom extending 
Fig. 266. 
to branches which have formed more than 
two annual rings. * * * In summer and au- 
tumn the blight of peach stems is always, 
or almost always, traceable to infection 
derived from mycelium. * * * This myce- 
lium originates in the rotting peach; bores 
through the pedicel into the stem; ramifies 
in the latter, especially near the place of 
entrance and quickly destroys all the distal 
portion of the branch. * * * The earliest 
varieties blight most, and trees not in fruit 
never blight at this time of year. * * * In 
wet seasons it [this twig blight] sometimes 
does more injury than the rot, because 
when many branches are destroyed the tree 
is not only injured, but the next year’s crop 
is proportionately reduced.” 
Treatment . — Owing to the rapid develop- 
ment of this fungus, and the fact that its 
presence does not become manifest until it 
is in the act of multiplying itself by spore- 
production, little can be accomplished by 
direct treatment. The spore formation may 
be checked somewhat by the application of 
sulphur but the destruction of the fungus 
growing within the tissues of the fruit, can 
only be accomplished by the complete des- 
truction of the fruit itself. Possibly, if the 
fruit is sprayed before infection has taken 
place, with some fungicidal solution that 
will adhere well to it, like the ammoniacal 
solution of carbonate of copper, the disease 
may be prevented to some extent. We 
deem this worth trying. 
As. a means of guarding against the dis- 
ease, and one which ought always to be 
practiced, all affected fruit should be gath- 
ered as soon as observed and destroyed or 
buried deeply in the ground. No diseased 
fruit should be left on the ground or hang- 
ing to the tree for it is from these that the 
fungus is able to breed disease in a succeed- 
ing crop. When the twigs are affected they 
must be cut off and burned, for in them the 
parasite may live from year to year. To be 
wholly successful this course of treatment 
must be vigorously and persistently follow- 
ed, not only by individual fruit growers 
but by all concerned. The spores of Monilia 
allowed to form in the orchard of the neg- 
ligent, may be wafted by the wind or car- 
ried by insects to that of the thrifty , and 
all the care and labor of the latter may thus 
be lost. Those in peach growing districts 
can ill afford to neglect this subject or rest 
in their efforts until a concert of action is 
enforced. 
'I lie ^miit of Onions. 
In the Annual Report of the Connecticut 
Agricultural Experiment Station, Dr. Ro- 
land Thaxter, the Mycologist, gives an ex- 
ceedingly interesting and well illustrated 
account of the more important fungus dis- 
eases of the onion. His report on the smut 
of onions is particularly full and valuable 
although it is modestly “presented as a re- 
port of the preliminary investigation” of 
this disease. We venture to make here 
some extracts from this report feeling sure 
that the information they convey will be of 
value to a number of our readers. 
The onion smut fungus is botanically re- 
