Pomona College Journal of Economic Botany 



27 



"You are quite right in your decision that the specimens represent injury 

 done by the wither-tip fungus, Collet otrichwm gloeosporioides. I beg leave 

 to differ with you, however, slightly in your statement that the opinion today 

 is that the wither-tip disease does not attack healthy growth. Mr. Jensen, 

 who worked on this disease last spring, maintained that the wither-tip did 

 not attack healthy growth in any part of California except certain situations 

 along the coast where the damp fogs and cold winds from the ocean seem 

 to bring about a condition which permits the fungus to act as a parasite 

 on lemons and oranges. He stated that in two places which he thought 

 wither-tip might become a parasite in California were in the vicinity of Santa 

 Paula and certain limited areas in the neighborhood of San Diego. In fact, 

 he found one place near San Diego where the fungus was undoubtedly as- 

 suming a role of a parasite and advised that the trees be sprayed with 

 Bordeaux Mixture. 



"We are very interested to learn of the additional case you describe on 

 Mr. Blanchard's trees and would suggest that the logical procedure would 

 be of course to spray with Bordeaux Mixture. 



"Would be glad to hear from you in the future in regard to developments. 



Very truly yours, 



"J. Eliot Coit, Acting Superintendent." 



With all of the past experience with wither-tip behind us and with the 

 added features already described we felt that immediate measures should 

 be taken by all to hold this disease in check. The present article, aimed for 

 the general public, is to set forth, as clearly as possible, the seriousness of 

 a problem which we may all of us have to face, and which many of us are 

 facing at the present time. Every possible bit of information has been 

 collected and included in the article so as to make it as thorough as our 

 present knowledge will allow. I am quoting very liberally from Mr. H. 

 Harold Hume, Prof. P. H. Rolfs and Mr. H. S. Fawcett, all of whom have 

 written valuable information concerning wither-tip. All correspondence rela- 

 tive to the subject has been included and in this shall be found much of the 

 latest in investigation. Mr. J. D. Culbertson, Assistant Manager of the 

 Limoneira ranch, has taken the time to give us the history and present status 

 of the work which has been, and is being, done there. Combining our own 

 observations, we trust that some value may be had from this first publication. 



HISTORY AND DISTRIBUTION 



The fact that the wither-tip had existed as a serious citrus pest in other 

 places first led progressive growers to fear it in this country. At the present 

 time it is known in practically every citrus growing section in the world 

 in spite of the fact that many hold that it can do damage only where certain 

 moisture conditions are secured. 



Of the general distribution Prof. Rolfs states, "The disease extends through 

 a large portion of Florida, the West Indies, South America, Australia, and 

 Malta. In Florida the diseases seem to be increasing in severity." Prof. E. 

 M. Underwood wrote : "This disease was found at only one point in Eake 



