district which was at that time already causing considerable loss. 

 Since that time much attention has been given to the disease, several 

 reports have been prepared^ (75) and extensive field observations 

 and laboratory studies are under way. 



Since the initial observations were made the trouble has not only 

 continued its ravages in the original territory, but has greatly enlarged 

 its boundaries so as to include an area extending from near Bayamon 

 to Anaseo, or approximately a quarter of the Island. As to how long 

 the disease had been present before the first report was recieved it 

 has not been possible as yet to ascertain, but certainly a 3'ear, so 

 that as near as is now known it has been active about three years. 

 The disease is as yet confined to the upper reaches of the river val- 

 leys, to smair inland valleys, and particularly to fields among the foot 

 hills. The broad stretches of the coastal plain, but little above sea 

 level, are still free of disease, although they are planted to the sus- 

 ceptible varieties of cane, and form great continuous areas. The 

 rolling stretch of country between Arecibo and Aguadilla, a region 

 M^hich suffers much from drouth has been the most severely infected, 

 ai)d hundreds of acres have been abandoned to cane culture. 



Losses. — The loss occasioned is very difficult to estimate since the 

 diseased fields will show a variation of from one to a hundred per 

 cent of infection. There appears to be a regular course followed 

 by the disease. A few stools are infected the first year, scattered 

 about the field. The second year infection becomes quite general and 

 there is a decided falling off in yield. The third year the growth 

 of the cane is so poor, and such stalks as are produced are so small, 

 and lacking in juice that the crop is a total loss. The loss is still 

 further increased by the fact that the Centrals refuse to receive any 

 cane that shows evidence of the disease. There is no doubt 1)ut that 

 the monetary loss already runs into the hundreds of tliousands of 

 dollars. 



Name of the Dv^ease. — Various names have been used for this 

 disease. It is universally known among the planters as ''La enfer- 

 raedad — the disease," and it has been called "the new disease," the 

 ''mottling disease" and "cane canker." The mottling disease is 

 the preferred term. Chlorosis is of course already in use for another 

 trouble. 



Symptoms. — The one marked and constant symptom of this disease, 

 and the one by which it is easily recognized by any one who has 



1 Stevenson, John A. — La Enfermedad Niieva de la Cana. Circuhii- 11, Tnsular Expori- 

 nient Station. 1917, 



In La Revista Azucarera, aiio 2, no. 24, p. 4-5, and no. 25, p. 5-6. 1917. 



In El Mundo Azucarero, v. .'>, no. 1, p. 19-24, fig-. 10. Aug. 1917. 



Cane Disease in Porto Rico. /ti La. Planter, v. 49, no. 5, p. 76-78. Aug. 4, 1917. 



229 



