CHESTNUT BLIGHT IN MICHIGAN 7 
blight has been found in this vicinity since that time. The writers found 
blighted trees in 1927 near Wayne in Wayne county and near Tecumseh 
and Clinton* in Lenawee county. In 1929, the blight was found in seven 
counties in Michigan, namely: Jackson, Lenawee, Monroe, Oceana,® St. 
Clair, Washtenaw, and Wayne. (Plate IVC.) In 1930, blighted chestnuts 
were found in Oakland county. Blight infection virtually covers the entire 
range of the native chestnut in the southeastern part of the State; it is firmly 
established on planted stock in Lenawee and Jackson counties and in the 
western part of the State it has killed several planted trees in Oceana county. 
It can be seen that the blight organism has infected not only the native 
chestnut but also chestnut which has been planted beyond the natural limits 
of the distribution of this tree. 
The finding of chestnut blight on planted trees near Tecumseh in 1927 
presents evidence indicating that the causal organism had been present in 
the State probably several years previous to its discovery. One of two trees 
found to be blighted was practically dead, the other nearly half dead. 
(Plate IV, A and B.) The first tree had only a narrow strip of bark a 
few inches wide and extending up one side of the trunk for about 15 feet 
as can be seen in Plate IV B. The remainder of this tree had already 
lost all of its bark. Examination of this nearly dead tree gave ample evi- 
dence of the presence of the blight fungus previous to the death of those 
parts as well as fresh blight cankers on the remaining living area. 
Although the falling of the bark is extremely erratic and, according to 
Baxter and Gill (1), cannot in itself be used as a criterion for estimating 
the number of years a tree has been dead, it is evident that chestnut does 
not become completely decorticated for several years after death. In gen- 
eral, Baxter and Gill find that as much as 23 per cent of the bark-area on 
the first log remains seven years after the death of the wood. From this 
determination, which is based upon a great number of trees on numerous 
permanent and temporary sample plots, it seems safe to conclude that the 
chestnut blight fungus had been present in this region of Michigan several 
years prior to 1927. 
The fungus has not been reported in the valuable chestnut orchards in 
the southwestern part of the State. These orchards, however, should be 
carefully watched as the blight was found by the writers in 1927 in a chestnut 
orchard of almost 100 trees at Bristol, Indiana. This particular location is 
within six miles of the Michigan and Cass county southern boundary lines. 
Blight Symptoms 
The first evidence of this disease is to be found generally on branches 
and sprouts. If the branches are killed during the growing season, the 
leaves die and cling to the twigs in very characteristic drooping clusters. 
This condition of the dead branches persists through the winter. So con- 
spicuous is the appearance of these dead branches with their leaves still 
hanging on them that they have received the name “flags.” (Plate III.) 
These flags are visible considerable distances from the infected tree and 
offer one of the first signs of the disease to the observer. In trees which 
are planted in isolated, exposed places, the breaking of the rather brittle 
branches in wind storms is of quite common occurrence. At first glance 
7 ‘This infection was first reported by E. C. Mandenberg and H. H. Wedgeworth. 
