. The bitter rot of apples. Apples; Bitter-rot. Fig. 2.—Diagram showing how the bitter-rot fungus decays an apple. The brown coloration of the spots on the apple frait is an indication of the decayed condition of the tissues immediately under the spots, in which region the threads of the bitter-rot fungus are bringing about changes in the firm tissue of the fruit which make it appear decayed. The lateral progress of the disease, evidenced by the increasing diameter of the brown area, is accompanied by a corresponding prog- ress of the disease into the fruit (figs. 2 and 3). The rotted mass, wh
. The bitter rot of apples. Apples; Bitter-rot. Fig. 2.—Diagram showing how the bitter-rot fungus decays an apple. The brown coloration of the spots on the apple frait is an indication of the decayed condition of the tissues immediately under the spots, in which region the threads of the bitter-rot fungus are bringing about changes in the firm tissue of the fruit which make it appear decayed. The lateral progress of the disease, evidenced by the increasing diameter of the brown area, is accompanied by a corresponding prog- ress of the disease into the fruit (figs. 2 and 3). The rotted mass, which is an inch in diameter at the surface, usually extends inward to the core of the fruit. The rotted mass shrinks somewhat in volume, hence the sunken character of the spot outside. There is usually a sharp dividing line between the rotted mass and the sound tissue. In this respect the bit- ter rot differs from the black rot of the apple. The size of the diseased areas on the fruit increases rapidly after an infection, and eventually the whole fruit may be affected. Where two or more separate infections take place the diseased masses fuse (PI. I). The separate rings of fruiting bodies join and the two sets of hyphse then grow on just as if there had been but one. The completely rotted fruit appears considerably shrunken, especially if there have been several cen- ters of infection. The fruit hardly ever deca}Ts entirely, as do apples attacked by the black rot; as a rule there are small patches of healthy cells which hold out a long time. The affected fruit falls from the tree during all stages of the disease. (See PL III.) In this case, as in other instances of fruit diseases due to fungi, a hastening of the ripening proc- ess takes place. The diseased fruits are heavier than ripe fruits, and are readily shaken from the trees. There are proba- bly other changes taking place in a dis- eased fruit which influence its condition and much as with fruits stung by various insects.
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherwashi, bookyear1903
