Journal of Agricultural Research 
Vol. XXIX, No 2 
92 
tamination, where the fungus attacks 
vigorous growing plants to some 
extent, occurring much more frequently 
on aging plants and on plant trash. 
3. The fungus has a wide tempera¬ 
ture range, its minimum lying below 
—2° C., its optimum between 22° and 
25° C, and its maximum at about 30° 
to 33° C. Infection was obtained 
experimentally throughout the tem¬ 
perature range of the fungus. It is 
obtained more readily below the 
optimum than above it. The rate of 
development of lesions is greater below 
the optimum than above it. 
4. The temperature reactions of the 
fungus are essentially the same on 
both agar and bud scales. Mycelium 
can cause infection without wounds at 
all temperatures within its tempera¬ 
ture range, whereas wounds are neces¬ 
sary for infection by spores. 
5. Moisture is the principal limiting 
factor for both spore and mycelium 
infection. High humidity followed by 
a decrease in humidity leads to sporu- 
lation. Temperature and especially 
moisture conditions in the artichoke- 
producing section of California are 
favorable for the growth of Botrytis 
with consequent contamination of the 
buds. 
6. Control involves field sanitation 
and possibly protective spraying or 
dusting of the buds; also careful 
handling to avoid unnecessary wounds 
in harvesting and packing. 
7. Control also involves the main¬ 
tenance of low humidity and of 
temperatures of about 5° C. in transit, 
although even at this temperature 
complete control is not possible after 
infection has occurred, because the 
decay, when once started, progresses 
at —2°, the freezing temperature of 
the buds. 
8. Responsibility for losses in transit 
or in storage is not single, but generally 
rests severally upon growers, packers, 
shippers, carriers, and storage men, 
each of whom could contribute some 
measure of prevention. 
