CITKUS DISEASES. ,j_L 



fere, replanting almost immediately is entirely feasible, following 

 ?. thorough working over the soil. 



In addition to this type of trouble, due for the most part to faulty 

 drainage, there has been present in a number of grapefruit groves 

 a condition for which it has been impossible to locate a cause. Af- 

 fected trees become unthrifty, there is a gradually increasing amount 

 of dying back, and after a number of years, death. Older trees only 

 are affected, and in so far as noted only those growing on the lighter 

 sandy soils in the Manati and Garrochales districts. Individuals may 

 be attacked, or small groups. In the latter case the disease progresses 

 outward from the center, attacking approximately a new line of 

 trees each year. There is some tendency on the tw^igs to multiple 

 buds, but no gumming, and no fungi are constantl}^ associated with 

 the trouble. A number of measures, particularly variations in fer- 

 tilizing and cultivation methods, have had no effect. Very severe 

 pruniugs have only delayed the inevitable death. Where it has been 

 possi])le to make examinations, the roots have been to a considerable 

 extent dead. 



Some observers have associated, this malady with Florida blight, 

 which it resembles in some respects, though differing in others. It 

 is not improbable that it is at least a closely related phenomenon. 

 Blight was at one time the most dreaded of all Florida citrus diseases, 

 and caused heavy losses. The cause was never ascertained, and but 

 one recommendation was made with, regard to it. to remove and 

 destroy all affected trees as soon as possible. The same advice will 

 apply here. 



rOOT-ROT OK MAL-DT-GOMMA. 



Tliis is one of the best known and most wide spread of all citrus 

 diseases, having been first noted in the x\zores as early as 1834, since 

 which time it has gradually spread to practically all other citrus- 

 growing regions. The damage caused by this one disease in the 

 various y)arts of the world, where it has l)een jiiwalent, will total 

 millions of dollacs; the loss in m sixteen-year period (1862-1878) 

 in Italy alone being estimated at two million dollars. Florida has 

 suffered very heavy losses. 



The disease has long been known in Porto Rico, it having heen 

 in fact the first malady to cause appreciable loss to the industry. 

 Many of the earlier groves, particularly lemon i)lantings, suffered se- 

 verely, even to the extent of the loss of a large percentage of the 



