190 
Journal of Agricultural Research 
Vol. XXX, No. 2 
on the surface of wounded fruit and in 
punctures similar to those made by 
stem or thorns. 
The fruit was prepared for inocula¬ 
tion either by cutting thin slices of the 
rind just below the oil cells and into 
the white portion similar to the wound 
made by a clipper cut or by punctur¬ 
ing the rind with a knife to the depth 
of about 2 mm. The depth the knife 
was thrust into the fruit was con¬ 
trolled by wrapping tire tape around 
the blade so that it could penetrate the 
fruit only to the depth required. The 
inoculations were made by rubbing 
spores on the cut surface, where a por¬ 
tion of the rind was sliced away, and 
by dipping the knife in a mass of 
spores when making the wound by 
puncture. The spores for inoculating 
the fruit were obtained from decayed 
oranges. Since the greater part of 
this work was done under ordinary 
packing-house conditions and with the 
regular packing-house machinery, no 
attempt was made to get pure cultures 
of the fungi for making inoculations. 
Decayed oranges were selected, how¬ 
ever, as the source of spores, because 
judging from the external character 
and color (1, 8), these seemed to 
furnish practically pure cultures of the 
fungi. 5 In many cases, undoubtedly, 
the fruit was inoculated from mixed 
cultures and there was especially in the 
controls considerable possibility of 
natural inoculations when the regular 
packing-house machinery was used in 
handling the fruit. 
In the early experiments the pro¬ 
cedure was to wound the fruit, treat 
it with a 2.5 per cent solution of borax, 
either by immersing or floating it in this 
solution, inoculating it by rubbing a 
finger dipped in the blue mold spores 
on the cut surface, drying in the air, 
wrapping, packing, and storing. The 
fruit was usually stored at about 70° F. 
with a humidity of about 90 per cent. 
Controls were prepared in exactly the 
same way except that instead of being 
treated with the borax solution they 
were treated with water only and inocu¬ 
lated with the fungi. At the end of one 
week the fruit was examined, the 
decayed fruits classified and removed, 
and the remaining sound fruits allowed 
to remain for the next inspection. 
When the fruit was immersed, it was 
held about 4 inches below the surface 
of the solution by a rack. When it 
was floated no weight was used, and it 
was allowed to float freely in the tank 
of solution, from one-eighth to one- 
tenth of the rind being exposed above 
the surface. The results of the ex¬ 
periments made with blue mold fungus 
on Valencia oranges are shown in 
Table I. 
Table I shows that there is much 
more decay in the untreated fruit after 
oneweek than in any of the borax-treated 
lots. In the latter the best results 
were obtained at the higher temper¬ 
atures and when the fruit was allowed 
to remain for four minutes or more in 
the solution. In no case was there 
more than 4.5 per cent of blue mold 
in any of the lots treated at 120° F. 
except in the two lots sprayed with 
water after being treated with the 
borax solution. In these lots the decay 
caused by blue mold after one week 
was 6.1 and 7.8 per cent. Evidently 
for the best results the borax solution 
should be allowed to dry on the fruit. 
At the higher temperatures blue mold 
is apparently controlled as well by 
allowing the fruit to float in the borax 
solution as by immersing it. At the 
lower temperatures, however, floating 
did not give as good results as did 
immersion. In the lots of fruit injured 
by puncturing and inoculating in these 
wounds, practically as good control 
was obtained as when the wounds were 
superficial. 
The results of the inspections after 
two weeks show some increase in the 
amount of blue mold present in the 
treated fruit, although in the lots 
treated at 120° for eight minutes there 
was in no case more than 5 per cent 
of blue mold decay. There was little 
increase in blue mold decay after five 
to seven weeks. The amount of decay 
caused by green mold was very much 
higher during the later inspections 
than at the first. This fungus is 
apparently not so easily controlled by 
borax as is the blue mold fungus. 
Results of a series of experiments on 
the treatment of Valencia oranges inoc¬ 
ulated with green mold are shown in 
Table II. The spores for inoculating 
this fruit were obtained from decayed 
specimens which appeared to be af¬ 
fected only with green mold, although, 
of course, as in the case of blue mold 
there was probably some contamina¬ 
tion. 
An inspection of Table II corrob¬ 
orates the observation indicated by 
Table I, namely, that green mold is not 
readily controlled by treatment with 
this concentration of borax. In the lots 
of fruit wounded on the. surface and 
immersed, there was no apparent infec- 
5 Thom, C. cultural studies of species of penicillium. U. S. Dept. Agr., Bur. Anim. Indus 
BuJ. 118, 109 p., iltus. 1910. 
