A MOSAIC DISEASE OF WINTER WHEAT AND WINTER RYE 
tling which appears to be due to faulty nutrition. This condition 
nearly always has a sequence of development on the leaves of a plant 
as follows: The flag 
leaves may show light- 
colored flecks on a 
predominatingly 
green background 
(fig. 3, B), but these 
flecks do not tend to 
follow the long axis 
of the leaf. Leaves 
next below the flag 
leaf may show a 
greater proportion of 
chlorotic surface, and 
the lower leaves may 
show very little green 
color (fig. 3, D). Al- 
though the pattern 
which develops on the 
leaves showing the 
advanced stages of 
this condition is simi- 
lar to that which oc- 
curs in cases of se- 
vere mosaic, the color- 
ation of the foliage 
differs in the two 
cases. In severe mo- 
saic the chlorotic 
areas (fig. 1, F) usu- 
ally are lemon yellow 
or faded yellow in 
color, whereas in the 
other case the chlo- 
rotic areas tend 
toward orange color. 
Cell inclusions have 
not been found in 
leaves showing the 
latter condition, but 
they are found usually 
without great diffi- 
culty in the cells of 
leaves showing the 
mosaic disease. 
1 INOCULATION) 
STUDIES 
Fig. 3. — A, Portion of a healthy Harvest Queen wheat 
leaf. B, C, D, Portions of Harvest Queen wheat leaves 
showing a mottling not caused by the mosaic disease. 
This condition appears to be caused by faulty nutrition 
or some other soil conditions. Natural size 
Six successful in- 
oculation experiments 
have been conducted in disinfected soil in the greenhouse at Madison, 
Wis., with the Currell and Harvest Queen varieties of winterj 
52843°— 25- 
