INJURIOUS INSECTS OF I909 AND IQIO. 163 
leaves. A contact insecticide must be used, the spray being thrown 
against the lower surface of the leaves. 
Lear Spot: There are at least two distinct fungi causing leaf 
spots on currant. The spots are usually circular in outline with a 
grayish brown center. The leaves may finally fall in serious cases, 
causing great damage. 
To control the disease, spray with bordeaux as soon as the leaves 
unfold, and continue at intervals of ten days or two weeks until five 
applications have been made. 
Powvery Mitpew: ‘The fungus produces grayish. cobwebby 
patches at first. These later become brown and felt like. Leaves, 
fruit and stem are attacked. 
Potassium sulfide used at the rate of 1 ounce to 4 gallons of 
water is the most efficient spray. Spraying should be begun just 
as soon as the leaves begin to appear, and should be continued at ten 
day or two week intervals until at least five applications have been 
made. It may be necessary to add one or two more applications. 
CANKER: The canker is produced as reddish eruptions on the 
stems; these eruptions may become dark later in the season. Twigs 
may be killed; in any case vigor is greatly reduced. Pruning may 
be necessary. However, since the disease enters largely through 
wounds, care in covering them or spraying with bordeaux, when 
such wounds occur, will be beneficial. 
Rust: Usually the rust is not very injurious. No extensive 
experiments in controlling the pest have been made, so that only the 
destruction of affected parts can be recommended. 
Ginseng. 
Buricgut: The leaves and stem are both attacked. Large, 
watery patches are produced on the leaves, and brown cankers are 
formed on the stem. The disease may spread rapidly and become 
very destructive. Infection in the spring seems to be caused by the 
spores which are on the ground. The plants are attaked as they 
come through the ground, the disease first appearing on the stems. 
In order to properly control the disease, it is necessary to spray the 
beds with copper sulfate, used at the rate of 1 pound to Io gallons 
of water, before the plants come up. Then, as soon as they push 
above ground, they should be again sprayed. This should be done 
every other day until the plants are fairly well along. Resin bor- 
deaux will adhere better than the ordinary mixture., 
