452 Report oF THE HorRTICULTURIST OF THE 
should be combined with-the Bordeaux mixture. A second 
brood of this insect usually appears in August. The only thing 
to be done is to spray when the indications are that the slugs are 
numerous enough to be injurious. On low trees they are some- 
times treated with air-slaked lime or road dust, by throwing the 
dust or lime over the trees. 
GENERAL TREATMENT AGAINST DISEASES AND INSECTS WHICH ATTACK THE 



PEAR. 
When to spray. What to use and what the treatment is for 
1. Just before blossoms open. ...... Bordeaux mixture#6 against the scab, 
leaf blight, leaf spot and canker dis- 
ease. 
2. Just after blossoms fall. Bordeaux mixture46 against the scab, 
leaf blight, leaf spot, ete. 
Paris green4? against codling moth 
and leaf-eating insects generally. 
3. From ten to fourteen days after 2. | Bordeaux mixture46 against the scab, 
leaf spot, leaf blight, ete. 
Paris green47 against codling moth 
and leaf-eating insects generally. 



For treatment of fire blight, bud moth, case bearers, etc., con- 
sult the special notice of these subjects on previous pages. 
PLUM DISEASES. 
BLACK KNOT. 
(Plowrightia morbosa (Sehw.) Sace.) 
Description.— This disease causes swellings underneath the 
bark, finally rupturing it and developing a spongy texture covered 
46 Use Bordeaux mixture, 1-to-11 formula. Directions for making and ap- 
plying are given in Bulletin 121. The Paris green or other arsenicals may be 
mixed with the Bordeaux mixture if desirable to apply both at one time. 
47 Use Paris green at the rate of 1 pound to 150 gallons of water, with 
about two pounds of fresh slaked lime added to make it adhere, and to pre- 
vent injury to foliage. Green arsenite of copper, arsenite of lime, or other 
poisons may be used instead of Paris green, as directed in Bulletin 121. 
These arsenicals may be mixed with Bordeaux mixture instead of water, at 
oe same rate as given above. In that case, not much extra lime need be 
added. 
