390 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 2 



The bromeliads absorb salts through the leaves instead of through 

 the roots, like nearly all other plants. Thus they receive a maximum 

 effect from any poison sprayed on them, while the tree roots are 

 protected by the soil which neutralizes the chemical before it can 

 reach them. The successful technique involved a 2-percent copper- 

 sulfate solution applied with the same spraying equipment used in 

 New England forests against gypsy moths. The pumps were moved 

 along roads and lines of hose run from them to reach all parts of the 

 plantations, the regular arrangement of the trees greatly facilitating 

 the operation. 



Although the killing of the bromeliads by chemical spray was suc- 

 cessful in controlling the disease, ultimately it would have to be 

 repeated unless the system of cacao cultivation were changed. Fortu- 

 nately, other centers of cacao production have developed a system of 

 close- planting the cacao trees to furnish their own shade and using 

 other trees as windbreaks only. It has the additional advantage that 

 the trees in the windbreak can be of a kind, such as the mango, that 

 is not only of value in itself but also is less favorable to bromeliad 

 growth. By converting to this system as new plantings are made, 

 Trinidad can be permanently freed from bromeliad malaria. 



BROMELIAD MALARIA IN SANTA CATARINA 



The intensification of malaria in Santa Catarina closely followed 

 that in Trinidad but was quite different in character. The area and 

 population involved were much larger and more diverse, making a 

 single solution of the problem impossible. This region comprises the 

 seaward slope of southern Parana, Santa Catarina, and extreme 

 northern Rio Grande do Sul (fig. 2). The five municipios in Parana 

 and the two in Eio Grande do Sul are relatively insignificant parts 

 of their states with a population of 60,000 and 22,000, respectively. 

 In Santa Catarina, however, the drainage divide formed by the crests 

 of the Serra Geral and the Serra do Mar swings deeply inland 

 making a seaward slope 100 miles wide, and on this slope are 29 

 municipios with a population of some 829,000 representing the great 

 majority of the agricultural population and practically all of the 

 vigorous industrial system (Pinotti, Rachou, and Ferreira, 1947). 



The area, although broader, is similar to the coastal slopes of 

 Sao Paulo where Lutz made the original discovery of bromeliad 

 malaria. Erosion has reached the maturity stage, with V-shaped 

 valleys and sharp ridges giving a very rapid run-off to rains except 

 for the retaining action of forests and small swampy areas by rivers 

 or close to the sea. Most of the cities and towns are packed tight 

 at the bottom of the valleys, whose abrupt sides until recently were 



