YOUNG WALNUTS AFFLICTED WITH BLIGHT 
The walnut industry of California has been seriously threatened by a bacterial disease, 
against which no remedy has yet been found. It has been discovered, however, 
that great differences exist among individual trees, in their resistance to this 
infection; and by propagating the most resistant trees, it is believed that groves can 
be created which will be practically immune to the disease. 
taken place, ranged from 6% to 95%, 
while the average amounted to 47.4%. 
These percentages are not given with the 
idea of expressing the exact amount of 
injury caused by this disease, as many 
nuts which are slightly blighted remain 
on the tree and may yield a commer- 
cial product. In calculating the extent 
of this disease, every nut which was 
blighted in the least was counted as dis- 
sased, and thus the comparisons are 
thought to be a fair indication of the vari- 
ation of the blight on the individual 
trees, but not necessarily an estimate of 
the damage to the grove. From our 
present knowledge it is very apparent 
that the disease resistance of individual 
trees varies considerably from year to 
year and under different soil and cli- 
matic conditions. The thorough test- 
ing of resistant varieties will require con- 
siderable time. 
64 
(Fig. 5.) 
Nut Characters.—The nuts are as var- 
iable as the trees themselves, not only in 
the exterior appearance but in the char- 
acter.of the meats as well. The ideal 
commercial nut should be of medium 
size, as 148 to 1% inches in diameter, of 
a regular oval form somewhat elongated, 
smooth surface, and light brown color, 
and uniform for these characters. The 
cracking quality of the nuts is quite as 
important as their exterior appearance. 
The nuts should be well sealed so they 
will not crack open in shipping. The 
shells should be thin but strong so the 
nut may be easily opened and the whole 
meat taken out intact. The pellicle 
should be light tan colored or silvery 
brown with a glossy waxed appearance 
attractive to the eye. The meat should 
be smooth, filled uniformly throughout 
the nut, averaging 50°% or more of the 
total weight, and with a mild, pleasant 
