CALIFORNIA AA^OCADO ASSOCIATION 



15 



one of the plantings. This fungus has been studied in several dif- 

 ferent culture media and has been inoculated in three different 

 avocado fruits to date. One of these fruits was already well ad- 

 vanced with other types of infection when inoculated, and satis- 

 factory results were not secured. 



"One fruit, which was a very beautiful ripe specimen of the 

 Topa Topa, was inoculated on October 13th at two points by intro- 

 ducing some of the fungus below the skin. At this writing, October 

 18th, these two spots are showing distinctly lighter areas about an 

 inch in diameter, and it is very evident that the fungus is producing 

 in this fruit the same type of rot as was found in the original fruit 

 of the Chappelow. AVe have, therefore, apparently proven that this 

 particular fungus is the cause of the very menacing-looking case 

 which was making its appearance on the Chappelow fruit. 



"That this decay is a serious matter is very evident from the 

 rapidity with which it spreads in the fruit and its effect in the 

 flesh. Several days after the first examination the original spot 

 was cut into and it was found that the flesh was affected to the 

 axis of the fruit. Although not very strikingly changed in appear- 

 ance, this flesh darkened more rapidly than the unaffected part of 

 the fruit and had a very disagreeable, mildly bitter and disgusting 

 flavor. 



"It will be of great interest to know what this fungus shall 

 prove to be from further study. According to present indications 

 it is not distinguishable from the fungus causing the black rot of 

 apples in the middle states. The same fungus also causes a very 

 destructive type of canker on the twigs and limbs of apple trees, 

 and from reports received from orchardists and friends in the mid- 

 dle states I judge it constitutes one of the most important factors 

 in the killing out of the farm orchards in that region. The same 

 fungus has been found in twigs of apple by Mr. Carrol Rodgers, of 

 Watsonville, and cultivated and studied by him while a student in 

 our laboratory. Apparently owing to the climatic conditions pre- 

 vailing in Cahfornia, this fungus is not so destructive here as in 

 the middle states, but it is evident that it exists here. Abundant 

 moisture and warmth at the same time are conditions which prob- 

 ably favor its development, and a combination of moisture with 

 cool weather is probably not so favorable to it. 



"Professor Fawcett has called attention some years ago to the 

 fact that this black rot fungus of the apple is closely related to the 

 very destructive decay organism of citrus fruits which causes the 

 greenish black rot of lemons and other citrus fruits. It is also inter- 

 esting to notice that in a recent report by Professor Earle and Mr. 

 Rogers, from the Isle of Pines, this second fungus is reported as 

 the most serious one with which they have to deal in the Isle of 

 Pines on citrus fruits, causing a stem-end infection of the fruit and 



