G8 
FLORIDA STATE HORTICULTURAL SOCIETY 
ture, which will keep the disease in 
check. They should be sprayed just 
when the young leaves are coming out, 
and at least twice afterward at intervals 
of two weeks. The fallen leaves should 
be gathered and burned. By carefully 
following out this line of prevention, 
there will be no difficulty in holding the 
disease in check, as it is not of a serious 
nature, though when left to itself it 
causes a very considerable amount of 
damage. 
STRAWBERRY LEAF SPOT. 
The leaf spot disease of the strawberry 
must be regarded as the most serious fun¬ 
gous diseases of that crop in our State. 
In fact, it is the only fungous disease at 
present known to the writer which 
causes any amount of damage to the 
plant. 
The disease affects the foliage and the 
first marks of its presence is the appear¬ 
ance of minute, purplish spots upon the 
leaves. These spots gradually enlarge 
and change in color, becoming a light 
gray in the center, but the periphery re¬ 
mains purple in color or with the inner 
edge shaded into brown. The spots are 
of different sizes, some are as much as 
three-quarters of an inch in diameter, 
though frequently a number of them co¬ 
alesce, forming blotches of irregular sha 
and of considerable extent. In the nat¬ 
ural process of the disease the substance 
of the leaf is destroyed. It becomes 
withered, brown and at length dry and 
dead throughout. If the season is in 
any wise unfavorable for the develop¬ 
ment of the plants, they are usually killed 
outright. If, however, this is not the 
case, the vitality of the plant is sapped, 
and the same quantity and quality of 
fruit need not be expected from affected 
plants. 
The disease is caused by a fungous 
parasite, Sphaerella fragariae (Tul) Sacc. 
Two kinds of spores are produced; those 
commonly known as summer spores are 
born upon conidiophores, which are pro¬ 
duced in tufts. These are to be found 
upon the discolored areas. The other 
spores are commonly called winter 
spores and are produced in small spore 
cases called perithecia. Both kinds of 
spores serve to spread the disease, and 
the latter (those produced in the peri¬ 
thecia) are useful in carrying the disease 
through unfavorable periods. The dis¬ 
ease exists upon the strawberry plant 
throughout the whole year in Florida, so 
that winter spores can scarcely be con¬ 
sidered as necessary to its continued ex¬ 
istence in the State. 
METHODS OF CONTROL. 
Two or three different methods have 
been recommended for the control of 
this disease. For old plantations, some 
writers have recommended the burning 
over of the crop. This, however, is not 
feasible, after the plants commence to 
bloom or are making growth previous to 
the blooming period. In small beds the 
diseased leaves should be cut off when 
first noticed, and if a little attention be 
given in this way it is not likely to give 
much trouble. In larger plantings, 
however, this is not feasible, and these 
should be sprayed. The results of my 
experiments at the Experiment Station 
this past season have been very satisfac¬ 
tory. In October forty-five different va¬ 
rieties of strawberries were planted. The 
leaf spot disease soon made its appear¬ 
ance and was allowed to run its course 
