INTRODUCTION 3 



This observation was followed by a series of experiments 

 by Millardet, who, in 1885, published the first formula 

 for the making of Bordeaux mixture and instructions 

 for its use. 



The development of the science of plant pathology 

 has been much greater and much more rapid in the 

 temperate and semi-tropical countries than in the 

 tropical parts of the world. This is no doubt due to 

 the prolific production of most tropical crops and the 

 lack of transportation facilities and market for perishable 

 products, which would enable the people to dispose 

 of their surplus or increased production. The rapid 

 development of tropical countries, the increasing demand 

 for tropical products, and the great advancement in 

 transportation facilities of the past few years have 

 stimulated a great interest in the plant pathology of 

 the tropics. 



Unfortunately, our knowledge of the diseases of 

 tropical plants is comparatively limited. The literature 

 is very much scattered, frequently popular, without 

 even a scientific reference to make the identity of the 

 disease possible, sometimes technical, and with little 

 data as to the economic importance of the disease under 

 consideration, and often unreliable. Some studies have 

 been made by correspondence, and on material after it 

 has been shipped great distances, and on plants grown 

 under glass in northern climates and inoculated with 

 organisms shipped from the tropics. Such studies are 

 valuable, but must sometimes be compared with actual 

 studies in the field before we can have anything like a 

 satisfactory knowledge of the diseases under considera- 

 tion. It is also unfortunately true that very few of our 

 workers have been able to make studies in more than 

 one tropical country. 



Some diseases are not so widely distributed as the 

 reports indicate, while others are, no doubt, far more 

 widely distributed. Lack of information concerning a 

 disease in a locality does not necessarily indicate that it 

 is not present. Many cases are on record where two 



