Proceedings Of The National Convention Of Fruit Growers PDF Download

Excerpt from Proceedings of the Ninth Annual Convention Held in Fruit Growers Hall, Bendersville, Penna: Wednesday, Thursday and Friday, December 17, 18, 19, 1913 The wooly apple aphis is readily distinguished from the others by the fact that it becomes practically covered with a bluish-white waxy substance secreted from its abdomen. It also infests the roots as well as the tops, which is not true Of any Of the other species found on apples. It has been discovered very recently that the apple, pear and hawthorn are really only the secondary or summer hosts Of this aphid - notwithstanding the fact that its agamic forms usually remain on them throughout the year - and that the elm is the real or primary host for the sexual generation and also 0 for the first two Spring broods and part of the third, all of which have been quietly operating for years under another name. This is just the reverse Of the host relation which the apple bears to the four other species. It also makes evident the hitherto unsuspected practical fact that both nurseries and orchards should be kept at a safe distance from all Susceptible species Of elms, and under no circumstances should such elms and apples be raised in the same nursery. The insect itself varies from a light green to a dark rusty brown color, and it attains a maximum length of about two milli meters, or a twelfth of an inch. AS multiplication proceeds the colonies gradually develop into small cottony masses, which are fairly conspicuous above ground, where they occur especially on succulent twigs or round abrasions or scars left by the pruning. In these Situations their feeding usually results in Objectionable swell ings or calluses, which Often distort the twigs and delays healing. Their presence above ground almost always indicates that others are feeding on the roots, where they develop conspicuous gall-like swellings or knots. These knots usually result in the death of the affected roots in a comparatively short time unless the injury is checked. This injury is especially severe on young trees, and the insect is usually distributed on nursery stock, by means of which it has already been carried to practically every im portant apple-growing region in the world. For this reason all such stock Should be carefully inspected for the typical enlarge ments, especially on the roots and the diseased trees should either by rejected or else all Signs of infestation Should be removed and the remaining roots dipped or thoroughly sprayed. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.