628 
Journal of Agricultural Research 
Vol. XXXI, No. 7 
At temperatures ranging between 27° and 30° C. a large proportion 
of inoculations were negative. While parallel agar cultures carried 
at these temperatures showed growth and development, the progress 
made was comparatively slow and the appearance of the culture 
was more or less abnormal, the growth of S. intermedia being more 
inhibited than either S. minor or S. libertiana. With the exception 
of S. intermedia , which stops growing at 30° to 31°, each of these 
cultures has shown ability to make slight growth on potato-dextrose 
agar at 32° to 33°. 
To determine the ability of these fungi to produce infection at high 
temperatures, freshly cut young carrot roots were inoculated and 
placed in a high temperature chamber. For the nine-day period of 
the experiment the temperature varied between 31° and 34°, with 
a mean of 32°. No growth was found in any culture. After these 
cultures were held for five days at room temperature there was 
no evidence of life. Control cultures run at room temperature showed 
vigorous growth and decay of the carrots within a few days, so there 
can be no question as to the viability of the organisms. Apparently, 
these fungi are unable to grow enough to establish themselves in the 
tissues of the host plants at a temperature of 32°. 
The amount of Sclerotinia decay found under transit, storage, 
and market conditions is necessarily dependent upon the extent 
of infection in the field. Once the product is contaminated with 
spores or mycelium of the fungus and has started on its way to 
market, the most effective method of controlling the amount of decay 
is by refrigeration. As experiments have shown, however, this 
method of control is somewhat limited. Under the present methods 
of refrigeration a car which maintains a temperature of 40° F. at 
the bottom and 45° to 46° at the top is considered a good refrigerator, 
but unfortunately Sclerotinia will develop and cause decay at these 
temperatures. The writer’s experiments show that S. libertiana , 
S. minor , and S. intermedia can infect freshly made wounds in suit¬ 
able host plants and cause ‘appreciable decay at these tempera¬ 
tures. In fact, the experiments conducted in cold storage show quite 
clearly that infection of freshly wounded tissues can take place even 
at 32° F. It is therefore manifestly impossible to get absolute con¬ 
trol of these fungi by any practical method of refrigeration which 
would not also be disastrous to the produce. From a practical 
viewpoint, however, the experiments snow that although incipient 
infections or contaminated wounds present at shipping time may 
develop decay at a temperature of 40° to 45° F., little spreading 
from one plant to another or development of decay in unwounded 
tissues is to be expected during the ordinary transit period. 
The most effective method of preventing Sclerotinia decay in 
transit is, of course, to prevent the loading of infected produce or 
badly wounded produce that has had a chance to become con¬ 
taminated. Clean, carefully graded vegetables will carry well under 
present methods of refrigeration at temperatures of 40° to 45° F. 
The precooling of vegetable produce is advisable whenever possible, 
however, on account of the fact that without precooling it takes from 
one to three days in the refrigerator car to reduce the temperature 
of the product to a point which is really effective in controlling 
Sclerotinia decay. Small lesions or contaminated wounds present 
