46 Pomona College Journal of Economic Botany 



I think it is practical to use the solution for circulation in the water jacket, 

 but it will require to be cleaned out occasionally, and probably will not be 

 as satisfactory as where clear water is used. 



We have been in the habit of dissolving about 50 pounds of sulphur at 

 a time, using a galvanized iron wash tub, and making our fire at any point 

 where it is most convenient to mix the material, but I believe it would be 

 better to have a central place for boiling, using a large cauldron. 



In regard to the effectiveness of this spray on the "wither-tip" I am not 

 wholly sure, though I have great faith in it. We are preparing to begin at 

 once using the Bordeaux Mixture on part of our orchard. Simply enough 

 to demonstrate whether there is any advantage in its use over the sulphur 

 sprays. I think that we have seen "wither-tip" years ago upon grapefruit 

 without in the least realizing what it was. During the years when we 

 sprayed with sulphur it disappeared. But for the past three years we have 

 been fumigating with the consequence that not only the "wither-tip" but 

 red spider, and even a little silver mite, have begun to reappear. So that 

 in any event a sulphur spray has become a necessity. 



I have not yet noticed any such dropping of green leaves in our orchards 

 as you speak of. I should be very glad indeed to have you send me the 

 bulletin on "wither-tip." 



Very truly, 



R. C. Allen." 



Instead of sodium sulfide spray we used the potassium sulfide, obtained 

 in the same way except that caustic potash was used as a solvent instead 

 of caustic soda. We believed that its value as a fertilizer over against the 

 negative value of the sodium as a soil constituent more than justified its 

 use even at a considerable increase in cost. This will explain Mr. Allen's 

 reference to the caustic potash. 



The sudden dropping of leaves mentioned of one portion of the orchard 

 extended more slowly to the entire orchard. June 17, 1909, I made the 

 following note : "Through lower half of orchard wither-tip generally dis- 

 tributed." 



July 12. — Prof. P. H. Rolfs, Director of the Florida Agricultural Experi- 

 ment Station and author of the Government Bulletin No. 52 on wither-tip, 

 addressed a meeting of the Southern California Lemon Men's Club at the 

 Chamber of Commerce in Los Angeles. He had spent a few days looking 

 through the orchards in the vicinity of Los Angeles and Whittier where he 

 found the fungus generally distributed. He considered it hardly necessary 

 to spray for the twig withering as he found it here, but he did advise the 

 spray for the leaf-spot and lemon-spot, as these manifestations of the fungus 

 result in loss of foliage and fruit. Florida experience in later years had 

 proven that the Bordeaux Mixture as weak as 4-4-50 solution was preferable 

 to any other spray known. 



Two days later Prof. Rolfs visited the Limoneira orchard. Like Dr. 

 Woods and Mr. Powell, he was surprised that the fungus has been able 



