CITRUS DISEASES. 



10; 



making: it apparent that conditions other tlian fungus attacks ar(> 

 primarily responsible. Observations show that the chief factor in 

 volved is the moisture supply, the drier the weather prevailing v.i 

 the critical time the greater the drop. Fruit lost under these con- 

 ditions would naturally be attacked by the omnipresent anthrac- 

 nose fungus, which is responsible for the browning and gunnning 



OIL BUENING OF FRUIT. 



Avery common form of injury to citrus fruits is one marked 

 by a sinking of the tissue between the oil cells, causing them to 



project prominently. The sunken areas 



arc normal in color at first, but finally 

 become brown. The spots produced are 

 irregular, may be one or several in num- 

 ber, and vary in size from the extent of 

 a few oil cells to large portions of the 

 surfac(\ This type of injury, although 

 noted on oranges, has been most serious 

 on grapefruit. 



The amount of fi-uit affectd varies 

 fi'oiii grove to grove and from time to 

 time, being correlated with the amount 

 of moisture jiresent. and the nature of 

 file handling received. It is commonly 

 observed that the spotting occur-s most 

 seriously during wet weather, and thai 

 green fruit is more subject to it than 

 that fully mature. It has been demon- 

 strated in California, and verified by ex- 

 periments here, that this tyi)e of blem- 

 ish is due to the injurious action of the 

 oil of the fruit itself, when liberated by bruising or othei- surfaci- 

 injury, in the presence of moisture. Even very minute quantities 

 are sufficient to cause the burning. 



After the initial burning there are no further developments un 

 less rot sets in. Ultimate disposition of fruit of this character d» - 

 pends upon the packing-house numagement. Tn some instances when 

 shipping ]-ot is very prevalent it is discarded, but it is generallv 

 merely placed in tlie lower grades, and has Ix^en found to carry 

 very well. The edibility of the fruit is, of course, not harmed. 



l'''i(;. HI. — Oilluirniiiu on 

 grHpofniit. 



