Fungous Diseases oe Coeorado Crop Plants 
45 
(3) Set out only healthy plants. 
(4) In severe cases spray young canes with Bordeaux mix¬ 
ture, 4-5-50 formula, with 2 pounds of resin-fish-oil soap added to 
act as a sticker. 
(a) First application, when canes are uncovered. 
(b) Second application, when new canes are 8 to 10 inches 
high. 
(c) Later applications, one or two more sprayings there¬ 
after at intervals of to to 14 years. 
Spur Blight. —This disease (Plate XVI) is found on the 
young canes and leaf-stalks. On the lower half of young green 
canes chocolate-brown discolorations are produced chiefly at the 
leaf attachments. Later this discoloration spreads, causing some 
buds to dry, shrivel and die. Other buds are so weakened that the 
newdy developed spurs die soon after starting. No fruit is devel¬ 
oped on the lower half of diseased canes. In later stages the dis¬ 
ease spreads and discolors the whole lower third of the cane a pur¬ 
ple-brown. In this stage the bark often cracks, causing drying of 
canes. Such stems are brittle and easily broken. Infection on leaf¬ 
stalk at first is in the form of a small chocolate-brown spot. The 
fungus spreads from this spot into the cane. Infected leaf-stalks 
are weakened and later collapse, causing the leaf to droop and 
dry up. 
Control .— (t) vSpray with Bordeaux mixture, 3-2-50 formula, 
with 2 pounds of resin-fish-oil soap added to act as a sticker. This 
mixture should only be applied to the young canes and not tO' the 
fruiting canes. 
(a) First application, last part of May or early June when 
canes are 8 to 12 inches high. 
(b) Second application, two weeks later. Regulate some- 
wdiat according to the ripening period of the fruit so as 
not to discolor fruit. 
(c) Third application, two weeks after the second. 
(2) Remove and burn old fruiting canes as soon as the berries 
have been gathered. 
Orange Rust. —This is a common disease attacking the 
leaves and canes. The under surface of infected leaves becomes 
covered with a mass of orange-red spores. The growth of leaves 
is retarded, and they become curled and distorted. Affected canes 
are weakened and stunted. They are non-productive and finallv 
die. The fungus lives in the plant from year to year. 
Control .—Pull up and burn all diseased plants. 
