. Bulletin. Agriculture -- New Hampshire. Dec, 1909.] SOME APPLE DISEASES. 113 The majority of the scab infections are made early in the season, but there is often a second spread of the disease in August. The young scab spots on the fruit at gathering time are evidence of this late attack. They do not, however, show the total amount of damage done by a late spread of the disease, as young scab colonies may continue to develop in storage and unsprayed apples apparently free from scab may develop the disease in storage if taken from an orchard in which a late spread of scab occurred. These scab
. Bulletin. Agriculture -- New Hampshire. Dec, 1909.] SOME APPLE DISEASES. 113 The majority of the scab infections are made early in the season, but there is often a second spread of the disease in August. The young scab spots on the fruit at gathering time are evidence of this late attack. They do not, however, show the total amount of damage done by a late spread of the disease, as young scab colonies may continue to develop in storage and unsprayed apples apparently free from scab may develop the disease in storage if taken from an orchard in which a late spread of scab occurred. These scab spots that develop in stor- age must have their origin either from colonies that were too small to be noticed at the time of picking or from spores carried into the barrel with the fruit. The scab fungus, like most other plants, is greatly checked in its growth by low temp eratures. Its greatest de- velopment 0 n stored fruit can therefore be ex- pected in bar- rels from cellar storage or which were delayed in reaching the cold storage plant. In some sea- sons there has been considerable loss from the development of scab on cold storage apples. One familiar with the disease as it occurs in the orchard is inclined at first sight to call the storage trouble a separate and distinct disease (Fig. 3). The fungus makes an unusual de- velopment beneath the cuticle before breaking thru and the mycelium is very dark in color. Consequently black, sunken spots develop on the apple and sometimes attain a diameter of one quarter of an inch before any break is evident in the skin (Fig. 4). The cuticle is finally ruptured and the usual form of spore and sporophore exposed (Fig. 5).. Fig. 3.—Scab on cold storage Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original New Hampshire Agricultural Experiment Station. [Hanove
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