EXPERIMENTS ON THE DECAY OP FLORIDA ORANGES. 27 



Several interesting facts are evident from the data recorded in 

 experiment 1 of Table I. Perhaps the most strilving thing here is that 

 fruits treated with mold spores were but little more subject to decay 

 than those not so treated. Another important pomt that may have 

 a wide practical bearing if further experiments confom it is the fact 

 that even though three days were allowed for the incubation of the 

 oranges treated with blue mold before they were removed to a 

 temperature of 15° C. (60° F.), no case of blue-mold decay resulted 

 in the refrigerator in a total of 19 sprayed with spores. Of the total 

 number of fruits decayed, only 28f per cent were rotted by blue 

 molds, while 7 If per cent decayed by stem-end rot. Two of these 

 fruits rotting at the stem end were afterwards shown to contain a 

 very rank-growmg fungus which has not yet s])orulated in culture, 

 while the others contamed Phomopsis citri. It is also worth noting 

 that of the oranges sprayed with Penicillium spores and held at room 

 temperature throughout the experiment, 38^ per cent decayed at the 

 stem end and only 10^ per cent had blue mold. Of the total of 58 

 oranges treated with mold spores, 24 decayed; of these, 20, or 83 J 

 per cent, were decayed by Phomo])sis, while only 16§ per cent of them 

 were rotted by blue mold. 



THE SECOND TEST IN WASHINGTON. 



In order to get an idea of any change that might occur m the per- 

 centage of decay as the season advances and to study further the 

 effect of refrigeration as a preventive of rot, another test was begun 

 on March 28. Mr. Leslie Pierce, who was supervising some spraying 

 work on the prevention of melanose in Florida, picked and sent to 

 Washington, D. C, from Orlando, Fla., melanosed, ammoniated, and 

 bright oranges to be used in the experunent. 



In this case some of the fruits were sprayed with the spores of the 

 common citrus blue mold, Penicillium italicum, and others with a 

 dark olivaceous species also found on oranges and which appears to be 

 Penicillium olivaceum. But owing to the fact tliat the application of 

 mold spores seems to have had so little effect the two fungi are not 

 distinguished in the records as given in experiment 2 of Table I. 



The data in this second experiment are again rather surprising, 

 both in regard to the relative numbers of oranges decayed by 

 Phomopsis citri and by mold and in regard to the effects of only 

 moderately low temperature in checking or preventing the decay. 

 Of 30 fruits sprayed with spores and held at room temperature, 14 

 decayed; 13 of them, or 92f per cent, were decayed by Phomopsis 

 citri, and only 7^ per cent by Penicillium. Only 5 of the total 17 held 

 in a refrigerator had been treated with mold s])ores; 1 of the 5, or 20 

 per cent, had a very sliglit indication of decay at the stem end. This 



[Cir. 124] 



