42 MISC. PUBLICATION 168, U. S. DEFT. OF AGRICULTURE 



Pink Mold Rot 



(Cephalothecium roseum (Ft.) Cda.) 



Pink mold rot was formerly more prevalent and destructive 

 than it is at present, because of the custom, now virtually dis- 

 continued, of piling apples and allowing them to sweat before 

 packing. While pink mold rot is usually found associated with 

 scab in the orchard, in storage, or in transit, occasionally it 

 enters the lenticels of fruit showing neither scab nor any other 

 injury. 



In its most common form, following scab, the disease has two 

 rather well marked stages with various transition stages between 

 them. In the first of these the rot appears as definitely sunken 

 brown bands about % inch wide encircling scab spots. On the 

 rotted area there is sometimes a growth of white fungus threads 

 or, under warm, moist conditions, a pink mass made up of these 

 threads and the pink spores they produce. If conditions are 

 favorable, the second or final stage of the rot soon follows. This 

 is characterized by chocolate-brown sunken areas of irregular 

 outline varying in diameter from V2 to 2 inches or even more. 

 Scattered over these areas are depressed, circular spots which 

 are lighter brown than the rotten area surrounding them (pi. 7, 

 B). Under market conditions this late stage of the rot is less 

 likely to show the white fungus threads and the pink spore masses 

 than is the first stage. At any stage the rotted areas are rather 

 firm and dry or at least are not watery, and the affected tissues 

 have a bitter taste. 



Pink mold rot is sometimes confused with fisheye rot, caused 

 by Corticiv.ru centrifugum. The two can generally be distin- 

 guished by the fact that on a fruit affected with pink mold rot 

 there may be a conspicuous white to pinkish growth of the fungus. 

 Spots of fisheye rot show very little fungus growth except under 

 conditions of high humidity, when a thin, white cobweblike mold 

 may develop. Pink mold is a shallow-growing fungus, pene- 

 trating the flesh about \q inch, whereas Corticium grows deeper 

 and in its late stage may extend to the core. 



Below 50° F. pink mold develops very slowly and is not at all 

 likely to start at new places; at 32° it is checked almost entirely. 

 Control is therefore best obtained by means of refrigeration. 

 Infection rarely spreads from one fruit to another unless scab 

 is present and the fruit is held at fairly high temperatures for 

 some time after harvest. 



(See 59, 65, lib.) 



Plum Curculio Injury 



(Conotrachelus nenuphar (Hbst.) ) 



OCCURRENCE, SYMPTOMS. AND EFFECTS 



Injury caused by the plum curculio is often found on apples in 

 the eastern half of the United States. Two kinds of punctures are 

 made : those for feeding and those for reception of eggs. In feed- 

 ing, the beetle cuts a small, round opening through the skin and 

 then eats out a cavity as deep as it can reach. When abundant, this 

 injury causes the apples to be badly deformed and misshapen (pi. 

 16). Punctures made for the purpose of laying eggs are partially 



