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NOTES ON SOME DISEASES OF THE 

 PINEAPPLE. 



By N. a. Conn 



From an examination of three pineapple areas in widely- 

 different parts of the world I should say that the ])robable 

 course of events to be expected in the growth of such an ag- 

 ricultural industry would be as follows : 



First, the introduction of fairly good seed pines on fairly 

 good land suitable to the industry. 



Second, a period of rapid growth during which the profits 

 are satisfactory. 



Third, a period of falling off in the yields, due to the accu- 

 mulation of the pests of the crop. 



Fourth, a period of loss, followed by the closing of many 

 of the concerns engaged in the industry, a period of keen dis- 

 appointment to many having money invested in the industry. 



Fifth, a period of adjustment, during which the profits are 

 small to nearly all concerned, until such methods of growth 

 are reached as can be permanently followed with paying re- 

 sults. 



I do not believe that the main features of this program can 

 be altered. I base this belief on the fact that there is nO' 

 known way of preventing the accumulation of the pests of 

 the crop. To a large extent it is possible to repair the deple- 

 tion of the soil due to the growth of the crops, and at a 'cost 

 that still leaves a good margin of profit. It is known that to 

 a certain extent the fall in yield, where pineapples follow 

 pineapples for a series of 3^ears, is due to what is commonly 

 termed exhaustion of the soil. It is m.y belief that this loss is 

 much less serious than that due to the accumulation of disease. 

 The diseases arrive in ways that are beyond our knowledge 

 in some cases, and beyond our observation in nearly all cases, 

 and hence are to a great extent beyond our control. We can 

 delay their arrival, and we can hinder their development after 

 they do arrive, at least in the case of those whose nature we 

 understand, but that is all we can expect to do. 



This may seem a rather gloomy picture, but I have put in 

 the darks first for several reasons. 1 have seen something of 



