648 
Joumal of Agricultural Research voi. xxviii, No. 7 
CONTROL 
Investigations as to the possibility of the control of the various field rots of 
strawberries by spraying and dusting are now in progress. The results which 
have apparently been obtained by a few growers indicate the possibility of 
success but it will be several years before definite recommendations can be made. 
Covering the ground with a mulching of pine needles is occasionally practiced 
in Florida, and apparently results in a lessening of the rot caused by the 
Rhizoctonia. 
SUMMARY 
A fruit rot of strawberries found to be important in central Florida is caused 
by a fungus which in its mycelial characters resembles Rhizoctonia solani Kuhn 
as commonly found on cultivated plants. 
When the berry is first attacked by this fungus the cells of the invaded tissues 
become somewhat hypertrophied. Later the cells of the decaying tissues gradu¬ 
ally collapse and the mycelium of the fungus which is at first intercellular be¬ 
comes both inter and intracellular. 
The “hard brown rot” caused by this Rhizoctonia is characterized by the 
fact that it regularly starts on the under side of the berry, advances slowly and 
shows a definite line of demarcation between the brown decayed portion and the 
normal uninfected pulp. In addition the berry is often distorted or “one-sided” 
in shape and particles of soil usually adhere tightly to the affected area. 
The “tan rot” caused by Pezizella lythri is confined to a somewhat cone-shaped 
region, the base of which appears as a tan-colored, slightly sunken spot on the 
side of the berry. This rotted portion may readily be separated almost intact 
from the sound tissue. 
The leather rot, caused by a species of Phytophthora is easily distinguished, 
if the fruit is cut open, by the fact that the vascular tissue becomes markedly 
discolored being a much deeper brown than the affected pulp. Berries rotted 
by this fungus are very bitter to the taste. 
The Botrytis or grey mold rot is not localized in any part of the berry as the 
fungus grows readily in all tissues. Berries affected by Botrytis are brown and 
rather tough without either the marked vascular discoloration or localized 
decay which are characteristic of one or more of the other brown rots discussed 
in this paper. 
