309 
1868. Huu, E. 5, (Alton, Ill.) Cryptogamous diseases, 
and root-pruning the pear—a preventive of blight. Trans. 
ll. Hort. Soc. for 1868, p. 35. [24 pages. } 
Same in part in Rep. Ind. Hort. Soc. for 1870, p. 42. 
[2 pages. | 
‘* Blight is induced by an extremely minute fungus.” The spores of it 
enter the tree by the pores of the bark. It ‘‘may be collected by a damp, 
-camel’s hair brush, and when macerated in water and placed in contact with 
the alburnum, as in budding,” produces a change which leads to ‘‘fermen- 
tation in the affected part.” The root-pruning remedy for blight was prac- 
ticed by him “‘some eighteen years ago.” The supposed physiological action 
is fully explained. Explicit directions for root-pruning are given; it is to 
be performed from November to April. A circular trench at least three feet 
deep is cut (and then refilled), eighteen inches from the trunk of a tree that 
is one foot in circumference, and three inches in girth. This is to be re- 
peated once in two years, adding three inches to the diameter of the trench 
each time. This forces the trees ‘‘to form their terminal buds . . . by 
the time the blight first appears,” which in that region is from May 25 to 
June 1. ; 
1868. Wuirr, Wm. N. Gardening for the South, rev. ed., 
1868, pp. 399, 428. [14 page on blight. | 
‘‘The great obstacle in pear culture is the blight, a disease whose virulence 
is almost peculiar to this fruit tree.” The frozen sap theory cannot be true, 
as the sap never freezes in the warm southern climate. Different methods 
of cultivation do not seem to affect it. Free use of the saw and knife is the 
only successful remedy. ‘‘Whenever the leaves begin to wither, or the tree 
ceases growing, at once examine the trunk and larger limbs for the gangrened 
spot, which is sure to be on one or both,” and when found amputate at once; 
“it will result in death to the tree if you let it go on.” A query is raised if 
this disease is not inherited from the quince by working on that stock, and 
continuously transmitted by seeds and grafts. ‘‘The quince is subject to the 
blight, like the pear.” 
1870. Huu, E. 8. (Alton, Ill.) Twig blight of the apple. 
Trans. Ill. Hort. Soc. for 1870, p. 220. [2 pages. ] 
‘‘Several small slices of bark going deep enough to include a thin slice of 
wood” were taken from some diseased apple shoots sent by a correspondent 
(E. Daggy), and inserted into succulent pear shoots as in budding. This 
was done during a period of hot, but dry weather. They were not looked 
at till a lapse of thirty-four days, when all were found blighted, it having 
extended from a half to two inches above and three to fourteen inches be- 
low the wounds. The conclusion is drawn that ‘‘the fungi causing pear 
and apple tree blight are identical.” In free growing trees twig blight 
often extends into the larger limbs and kills them. ‘‘There are many causes 
which retard blight, such as non-cultivation, drought, seeding the ground 
under the trees to grass, over-cropping, root-pruning, etc.; in short, any- 
thing inducing early maturity, or tending to arrest the rapid flow of sap.” 
An instance is given of the harm done an apple orchard by too severe prun- 
ing, inducing rapid growth and great destruction from blight. 
PEER 
1872. Barry, Patrick. Fruit Garden, 2nd ed., 1872, p. 
449. [1 page on blight. | 
Same, new ed., 1883, p. 474. [1 page. | 
Treated under headings: ‘‘Fire blight of pear, apple and quince,” ‘‘twig 
