40 
Colorado Experiment Station 
STRAWBERRY. 
Leap Spot or Leaf Blight. —Although this disease is of 
frequent occurrence in strawberry beds, it rarely becomes serious. 
It attacks the leaves principally and may be recognized by the char¬ 
acteristic white spots bordered by red or purple. At first the spots 
are purplish. The degree of susceptibility of a variety toward the 
disease varies with the locality. 
Control .— (i) Remove and destroy all diseased leaves when 
setting new plants. 
(2) The fungus winters over on the leaves. Hence, after the 
picking season, mow the bed and burn it over. 
(3) Although seldom necessary, it will pay to spray in bad 
cases. Use Bordeaux mixture. Spray 2 or 3 times early in the 
season, and, if necessary, once later. 
(4) Resistant varieties for a locality may usually be found. 
Black Root. —Many plants have been sent to the Station af¬ 
fected with a disease, which we have called “black root.” There is 
a blackening and dying of the roots. As a rule, two-year-old plants 
are the worst affected, and the disease usually becomes evident in 
the spring. In a few cases, the trouble has appeared at the begin¬ 
ning of the winter season. No causal organism has as yet been 
associated with the disease. It seems to be most prevalent on soil 
that is poorly drained, or in bad physical condition, or on land that 
has been continuously cropped with strawberries without proper 
rotation with some legume. However, it has been noted in soil 
apparently in good condition. 
TOMATO. 
Fungous (Piisariiiin) Bijght.— -In this disease the first in¬ 
dication is a yellowing of the lower leaves, followed by their wilt¬ 
ing and dying. The trouble may progress slowly, or within a week 
the entire plant may be dead, depending upon weather conditions 
and the severity of the attack. In a section of a diseased stem, the 
woody portion is blackened. Very often the fruit remains attached 
to the plant and ripens earlier than usual. This is probably the 
same fungus that is responsible for a part, at least, of wilt in po¬ 
tatoes. 
Control .— (i) Spraying is useless. 
(2) Remove and burn infected plants. A single diseased plant 
may be the source of infection of a large crop. 
(3) The disease may live in the soil from year to year. Prac¬ 
tice a crop rotation system in which tomatoes and potatoes do not 
come oftener than once in four years. 
