RASPBERRY DISEASES 413 
blight no insect burrows are found. The disease has also 
been confounded with drought and winter-injury. Drought- 
injured canes dry up slowly and more uniformly ; blighted canes 
die suddenly. Winter-injured canes do not put out new leaves 
on the affected portion; blighted canes | 
develop new leaves on the affected parts. 
The berries dry up as a result of cane- 
wilt (Fig. 120). They are also susceptible 
to direct attack. This is evidenced by 
the fact that a single berry in a cluster, 
or even one side of a berry, may be dis- 
eased. The normal green color is slightly 
tinted as if ripening prematurely; fi- 
nally, the tissues gradually turn brown 
and a dry rot results. 
Cause. 
The brown mass of reproductive bod- 
ies, already mentioned, which ooze out 
on the affected bark are the conidia 
of the causal fungus, Leptospheria Con- 
tothyrium. These spores are dissem- 
inated from plant to plant probably Ge Gee 
by insects (tree crickets), wind and gene on paepbErky cars, 
dashing rain, by pickers, pruners and 
cultivating tools. The spores germinate on the canes, and 
evidently the germtubes are capable of penetrating the un- 
broken epidermis of the canes. The fungus also enters the 
canes through wounds; stubs left exposed in heading-back 
and injuries made by the snowy tree cricket (Ecanthus niveus) 
are common points of entrance. Berry-infection doubtless 
occurs through the flowers and very young fruit. The mycelium 
works between and within the fleshy parts of the drupelets, 
but not in the embryo or stony part. It passes from the 
fruit down the pedicels and thence upward to other berries of 
