458 Various Blights. 
Toadstool Destruction—Trees are often destroyed through 
invasion by toadstool fungi from decaying roots or wood with 
which their roots come in contact. The injury is often not 
detected until the tree is ruined and it is too late for treatment. 
If only part is affected, the disease may sometimes be arrested 
by cutting away the diseased parts and disinfection of the ex- 
posed tissue with the Bordeaux Mixture. 
Moss, Lichens, etc., on the Bark.—It has been clearly shown 
by investigation at the University Experiment Station that the 
growth of moss, etc., upon the bark of fruit trees is a decided 
injury. All trees should be assisted to maintain clean, healthy 
bark. This is accomplished by the use of the lime, salt and sul- 
phur mixture already prescribed for scale insects. It can also 
be done by winter spraying with caustic soda or potash, one 
pound to six gallons of water. 
Blights and Decays.——There are several blights which are 
traceable to bacteria, parasitic growths which are not discernible 
as are the fungi, and not usually amenable to spray treatment, 
because they exist wholly within the tissues of the plant and are 
not reached by applications. The blights of the pear, the black- 
heart of the apricot, etc., are instances. Cutting back to healthy 
wood and burning all removed parts is the best treatment which 
can at present be prescribed. 
A local disease which has been demonstrated hy Newton B. 
Pierce, of Santa Ana, is the bacteriosis of the English walnut. 
The disease is recognized by black sunken spots on the hull of 
the voung walnut; generally worst at the blossom end and usual- 
ly first seen there early in the season; later the spots run to- 
gether and encompass considerable areas of the surface. As. 
the disease progresses the nut is transformed into a hateful black 
mass and is utterly destroyed. ‘The disease also affects the 
leaves and young wood. The fallen nuts and leaves should be 
plowed under deeply or gathered and destroyed. The tree 
should receive careful pruning to remove all diseased parts. It 
may be well to spray voung trees in the winter with the Bor- 
deaux Mixture for the purpose of disinfecting the tree as per- 
fectly as possible. 
DISEASES NOT TRACEABLE TO PARASITIC GROWTHS. 
There are a number of prominent troubles which are not 
traceable to parasitic invasion of any kind, and yet may be in 
some cases promoted by bacterial growth invited by preceding 
conditions. 
Sour Sap.—There is a fermentation of the sap, quite notice- 
able by its odor, which may be found in all parts of the tree, from 
the roct to the topmost twigs; sometimes in one part and not 
in another. Sour sap in the root is generally due to standing 
