52 
Journal of Agricultural Research 
Vol. XIV, No. i 
the inoculations had been made. No evidence of the disease appeared 
on any of the control plants. On August 6 virus was obtained from the 
blighted plants and used to inoculate several seedlings grown in a pot 
in the greenhouse under insect-free conditions. A similar pot of spinach 
seedlings was untreated and served as a control. On August 22 it was 
observed that the plants inoculated on August 6 had developed the char¬ 
acteristic mottled appearance of blight. All the control plants remained 
healthy. This gives definite proof that spinach-blight occurs in western 
New York as well as on Tong Island. 
Ohio. —Two boxes of diseased spinach plants of the Viroflay type were 
received from Ohio. These plants were in various stages of what ap¬ 
peared to be typical spinach-blight. In Ohio the disease is known by 
the name of “yellows” (PI. 10, A). 
Individuals of both Macrosiphum solanifolii and Rhopalosiphum per- 
sicae were present on the plants. Aphids were removed and placed on 
pots of Savoy spinach seedlings growing in the greenhouse. Similar 
plants were used as controls. Mottled leaves were removed from each 
of the plants from which the aphids were taken, and Savoy spinach 
seedlings were inoculated by mashing the mottled leaves into them. Ten 
days after inoculation it was observed that some of the potted seedlings 
were showing doubtful symptoms of blight. Six days later some of the 
inoculated plants had developed characteristic symptoms. The control 
plants remained healthy. 
At the same time the inoculations were made in the greenhouse, plants 
in one of the field cages were inoculated by mashing the diseased tissues 
from the Ohio spinach into the leaves. A number of plants were thus 
inoculated, and a similar number were pricked with a flamed needle 
serving as controls. Sixteen days after inoculation some of the plants in 
the field cage had developed typical symptoms of blight, but the control 
plants remained healthy. Six days later one of the mottled leaves was 
removed from each of the two blighted plants in the field cage. Pots 
of spinach seedlings 16 days old were inoculated by mashing the dis¬ 
eased tissues into the cotyledons of the seedlings. A similar pot of plants 
served as a control. Eight days after inoculation 14 of the plants devel¬ 
oped positive symptoms of blight, the control plants remaining healthy. 
Twelve days after observing positive symptoms of blight in the field cage 
one mottled leaf was removed from a blighted plant, and with it 16 plants 
20 days old and 29 plants 11 days old were inoculated by mashing the 
diseased tissues into the cotyledon and the first true leaves. Eleven 
days after inoculation the majority of the plants in each of the two pots 
had developed mottled leaves, but the control plants remained healthy. 
From these results it appears that the Ohio spinach is subject to the 
same disease which is present in the Norfolk section and that the disease 
is caused by the same virus which causes spinach-blight in Virginia. It 
is interesting to note that spinach-blight vims is evidently readily trans* 
