Cir. 124— C] 



EXPERIMENTS ON THE DECAY OF FLORIDA ORANGES. 



By J. G. Grossenbacher, Pnthnlogist, Fruit-Disease Investigations. 



INTRODUCTION. 



The oranges that dropped and decayed in many groves in Florida 

 during the past season probably amounted to half of a medium- 

 sized crop, but the trees had been so heavily loaded to begin with 

 that the citrus gi'owers generally had a very profitable year. Drop- 

 ping and some decay first became very noticeable in severely ammo- 

 niated - groves during the latter part of October and gradually 

 increased until the first part of December, 1912, when not only was 

 the ground beneath the trees of ammoniated and melanosed groves 

 covered with moldy fruit, but many trees had large numbers of 

 decaying oranges still attached. The musty, moldy smell of such 

 groves was noticeable at some distance. In a few small sections 

 of the State melanose and ammoniation were practically absent. 

 In these sections the "drops" were compai-atively few, and decay, 

 both on the trees and in transit, seemed no greater than in other 

 years. As might have been suspected, the heavy losses from decay 

 in shipping were chiefly confined to the sections and groves in which 

 the dropping of fruit and decay, both on the ground and on the 

 trees, had been great. During most of December it was not uncom- 

 mon to hear reports of 20 to 60 per cent of decay in transit to market 

 from such sections, and sometimes as high as 80 per cent decayed. 



The causes of this great loss by dropping and decay are, perhaps, 

 several and may be very complex, but it seems likely that the con- 

 ditions responsible were, at least in part, the same as those causing 

 decay in transit. While the most active agents of decay apparent 

 in the groves during fall and early winter were the blue molds, it is 

 not so evident how these rot organisms gained entrance to the fruits, 

 except ui so far as rinds had spht or had been broken in some 

 other way. In October and again in December, many oranges in 

 very early stages of decay were found still attached to trees, and 

 by careful examination with an ordinary hand lens it was sometimes 

 possible to find one or more very minute clefts in the rind near the 



1 Issued May 3, 1913. 



2 The words " amnion iai ion " and "melanose" are frequently used in Ihis paper for lirevity in referring 

 to groves having ammoniation or die-back spots and melanose roughenings on the fruit. ' 



[Cir. 124] 17 



