Gumming

Gumming (in vegetable pathology Gummosis), a disease which attacks the plum, cherry, peach, and other stone fruit-trees, often proving fatal to the limbs attacked, and ultimately also to the whole tree in virulent cases. Recent observations seem to prove that the cause of the disease is a fungus named Coryneum Beijerinckii. The mycelium of the fungus develops a ferment which transforms the cell-walls, starch granules, and other contents of the cells into gum. While in some cases the mycelium is obviously the exciting cause, in others the ferment only appears to be the contagious agent. One point seems quite clear—the fungus cannot penetrate sound healthy bark—there must be some wound or abrasion before the germ-tubes can enter the cellular tissues in which alone they can spread. Unfortunately such injuries occur from many causes in the class of trees named, and probably insects are the chief agents in carrying the contagion from tree to tree. In prescribing remedies, those that are preventive are obviously best. Wounds as soon as they are observed should be coated with a thick paste of quicklime or coal-tar. Gummed branches should be cut away without delay and burned, and the wounds dressed at once with coal-tar.—It is conjectured that Coryneum or some similar fungus is the cause of the disease that produces gum-tragacanth, and probably other gums and gum-resins.

Gumri. See ALEXANDROPOL.