'JZ STATE POMOLOGICAL SOCIETY. 



made during the winter of 1906 and 1907 in Iowa. In the 

 course of the investigation over 30 bushels of fruit were very 

 carefully examined. These 30 bushels, including specimens of 

 30 leading varieties, were obtained from different parts of the 

 state, some coming from sprayed and some from unsprayed 

 orchards. The fruit was grown on a variety of soils, under 

 different orchard conditions, picked at varying degrees of 

 maturity, handled in different ways, and examined at different 

 times so that the results obtained may be considered as fairly 

 representative. These 30 bushels of apples contaified 3918 

 fruits, 788 (or 20%) of which were either partially or entirely 

 decayed. Approximately 18% of these 788 fruits were decay- 

 ing with soft rot or blue mold; 9% with pink mold; 5% with 

 brown rot; 5% with an unnamed rot (some species of Alter- 

 naria, Macrosporium, or Cladosporium) ; 4% with black rot; 

 and less than 1% with bitter rot. In most of the remaining 

 58% decay was just starting and no fruiting forms of the fungi 

 were visible so it was impossible to identify them with certainty. 

 Without doubt at least 90% to 95% of these unidentified forms 

 would have developed into some of the diseases enumerated 

 above had opportunity been offered. In several test cases these 

 forms did develop into the above easily recognized decays. 

 Thus, it will be seen that blue mold, pink mold, brown rot, the 

 unnamed rot. and black rot were causing practically all the 

 decay of apples in Iowa, their percentages becoming 43, 21, 12, 

 12, and 9 respectively. The percentage of loss from others was 

 so small that it was almost negligible. 



Of these 5 diseases or 5 classes of disease blue mold was by 

 far the worst, doing nearly as much damage as all the rest put 

 together. Now let us inquire how this disease gets started in 

 the fruit. In 120 (or 96%) of the 125 cases of soft rot found 

 the point of infection was a bruise in which the skin of the fruit 

 had been broken. In two instances for a little more than 2%) 

 the fungus had entered through scab wounds. In two other 

 instances entrance had apparently been made through the 

 unbroken epidermis. It should be stated, however, that both 

 of the apples infected through the unbroken epidermis were 

 lying right against other apples decaying from blue mold and 

 it is possible their skins were softened by the juices and lique- 



