DISEASES OF CULTIVATED PLANTS 369 
Pk.,) which attacks both fruit and branches and is a bar to successful maturity 
of Northern Spy, Smith’s Cider and some other varieties at certain times. It 
also invades storage apples and this rot is the most universal one in ordinary 
cellar storage. With varieties adapted to climatic conditions, methods of hand- 
ling by sprays and destruction of cankers and mummy fruits should prove as 
effective as with bitter-rot. Unfortunately the varieties which most commonly 
suffer from black-rot are those growing beyond their safe range of conditions. 
Brown-Rot. There is a rarer rot fungus (Sclerotinia (Monilia) fructigena 
(Pers.) Schrt.) than that of black-rot, which also attacks the apple in some 
parts of the United States. For our region it is little known on the apple and 
probably less important than either of the preceding. 
Brown Spot or Dry-Rot of Baldwin. Very frequent complaint is made of small 
sunken spots in fine specimens of Baldwin and some other varieties. Internally 
these sunken spots are dry and somewhat bitter, leading to general breakdown 
of the apple. These spots have been referred toa particular fungus, (Phyllachora 
pomigena (Schw.) Sacc.,) but the case is not proved. This internal brown 
spotting also occurs in Northern Spy and in Fameuse, and we hear complaint 
of losses from it. The causes of the internal spotting are probably the same in 
all cases and must in part be regarded as physiological breakdown. New 
Hampshire Experiment Station (Bulletin 45) succeeded in controlling the form 
of this. dry-rot on Baldwin by the use of Bordeaux mixture. Some irregularity 
in results from spraying for it have been recorded elsewhere. 
Canker. These diseased conditions upon branches may oocur in the propaga- 
tion of. bitter-rot, but are more commonly referable to the black-rot fungus, 
(Sphaeropsis malorum Pk.,) or to the 
blight bacterium (Bacillus anylovor- 
ws Burr.) (See Bulletin 163, New 
York Experiment Station and Bul- 
letin 235, Cornell Experiment Sta- 
tion) although other fungi are 
common in Europe as the cause of 
canker. Among these are species 
of nectria. Probably the canker 
due to the black-rot fungus must 
contest with that due to the blight 
bacterium for first place in Ohio, 
and its control is interwoven with 
the control of the black-rot on fruit. 
Canker-like dying of the external 
bark may, and sometimes does, 
occur without immediate penetra- 
tion to the inner bark layer or 
injury to the branch. All these 
cankerous developments are, how- 
ever, a source of danger and call 
for continuous watchfulness. The 
conditions of the fungus attacks are Fig. 29. Apple branches attacked by canker. 
those of possible rifts in the outer 
bark followed by the localizing of the fungus development. Those for the blight 
canker are more extended and include blossom spurs. (See twig blight and 
pear blight). Itseems probable also that the power of resisting attack varies 
with the vigor of the branches. Up to this time our remedies have been largely 
