FIRE-BLIGHT, or PEAR-BLIGHT. One of the most destructive diseases of pears, apples, and other pomaceous fruits. While not as regu lar in its attack as some other plant diseases, no other is more destructive when it does appear. Fire-blight is a contagious bacterial disease due to Mieroeoecus amylovorns, which gains entrance through the soft tissues of new growth such as twigs and young fruits, through wounds made by insects or otherwise, but especially through the nectaries and stigmatic snrfaces of the blos som, from which point of infection the bacteria rapidly spread, killing the tissues as they progress. The leaves are sometimes attacked, but usually they die as a result of the destruction of the twigs, and they remain dried and attached to the brandies. forming one of the most striking fea tures of the disease. The part attacked is the cambial layer of the twigs, down which the dis ease passes to the branches, and finally to the trmik. Its rate of progress is not very rapid. and. 11111`11 it has run its course, the line of demarkation between sound and dead wood is easily seen, Upon bearing trees the first place of attack is usually in the blossoms, the germs being spread from flower to Clover and from tree to tree by bees and other insects. The disease may be recognized by clusters nf blessoms turn ing black. From these the disease spreads. It seems to winter over in infections that have oe eurriA Pale in the summer. The infected bark is
moist, and in the spring gum exmles from the diseased area. This is especially attractive to bees, which carry the germs from the gum to the flowers. Rapid growth of the trees, which may he caused by severe pruning or by too much nitro genous food in the soil, favors the spread of the disease. Anything that will cheek the growth of the trees, such as withholding cultivation and nitrogenous fertilizers, should be adopted. The most satisfactory treatment is to cut out and burn all blighted limbs while the trees are dor mant. All parts suspected of infestation should be carefully examined and severely pruned back six inches or a foot below the line of separation between sound and diseased wood. The best time to do this is in the autumn, when the contrast between the diseased and sound branches is most striking. A careful inspection of the trees should be made several times during the summer, and all new infections should be cut out and burned. If all pear, apple. quince, crab, hawthorn, and al lied plants be looked after in this way, the serious spread of the disease may, to a great degree, he prevented.
For a full account of this disease, consult Waite, in United ,States Department of Agricul ture Yearbook for 1895 (Washington, 1896).