The following paper was read by Ernst A. Bessey : 



Air Drainage as Affecting the Acclimatization 

 of Plants. 



BY ERNST A. BESSEY, 



Pathologist in Charge of the Subtropical Laboratory and Garden, 



Miami, Florida. 



To those living in Florida is offered a most excellent op- 

 portunity to see extensive experiments in acclimatization and 

 to note some of the factors influencing their success or failure. 

 Besides the numerous importations in recent years by the United 

 States Department of Agriculture, there have been ever since 

 the settlement of the State, innumerable attempts to establish 

 plants from all parts of the world, from both temperate and 

 tropical regions. It was to be expected that only a small per- 

 centage of these attempts would result in success on account of 

 the many factors coming into play. For instance, the question 

 of soil has probably accounted for more failures than any other 

 factor except minimum temperature. In almost the entire State 

 of Florida the soil is to a very large extent composed of sand, 

 in many places very deep and with no subsoil. In these sandy 

 soils the large annual rainfall (50 to 60 inches) is counter- 

 balanced by the porosity of the soil, which often causes the death 

 of a plant from lack of water, while in the heavier soils of Cali- 

 fornia the same plant may thrive with a far smaller annual 

 precipitation. The lack of plant food in this sand must also 

 be taken into consideration, as it is of great importance, it being 

 impossible to replace it satisfactorily in all cases by the use of 

 fertilizers. 



Another very important factor is the fact that in Florida 

 the chief period of rainfall is in the warmer months. This is 

 distinctly advantageous in most cases, being in direct contrast 

 to the conditions in California, where the rainy season is in 

 winter. 



