94 JOURNAL OF AGRICULTURE OF P. R. 



equally effective. The weekly program is, however, much to be pre- 

 ferred to none at all. 



As to the strength of solution to use, 1 to 30 is that usually rec- 

 ommended. This strength is very effective for rust mite, but does 

 not kill a very large percentage of scale insects, nor is it as efficient 

 a scab preventive as is desired. 



It is therefore recommended that a strength of at least 1 to 2") 

 (concentrate at 32^ B.) be used for the second and third applica- 

 tions. Further tests may even make it desirable to use a greater 

 concentration than this, but care must be taken to prevent excessive 

 injury to young growth. It would be advisable for each grower 

 to conduct experiments of his own as to the strengths that can be 

 used without burning. 



The important thing to be remembered is to make thorough ap- 

 plications at the critical time, using the material as strong as is con- 

 sidered safe. 



The preceding lime-sulphur program may well serve for many 

 groves, but it is unfortunately true that there are others so severely 

 disease-ridden as to require a more, strenuous program. For these 

 the Florida schedule is recommended. The first spraying may be, 

 as before, of lime-sulphur (1 to 25) before the bloom appears, a 

 sort of clean-up spray to remove old scabby leaves and help pro- 

 tect the new growtn. Then the second application is Bordeaux mix- 

 ture (,3-3-50) at the height of the bloom, followed witliin a week 

 or ten days by another at the same strength or by strong lime-sul- 

 phur, depending upon the weather and other conditions. The first 

 application, however, other things considered, should be all the Bor- 

 deaux given, except in very exceptional cases, though this again 

 must be left in large part to the grower's discretion. One or more 

 additional lime-sulphur sprays may be given, if necessary, at the 

 usual intervals. 



MELANOSE (Phomopfsifi eitri). 



Melanose, a serious disease in Florida, has been reported several 

 limes from Porto Rico, but it appears that for the most part these 

 reports have been erroneous, or tliat true melanose has been con- 

 fused with greasy spot, a phenomenon of universal occurrence. True 

 melanose has been found in a few groves only, and even in these 

 cases has been confined to one or at most a few ti-ees only. The most 

 characteristic example found was cm a sweet-orange seedling, which 

 was severely infected, together with one adjoining grapefruit tree 

 partially overhung by tlie orange. It has l)een observed by Faw- 



