Use of Growth Substances in Tropical Agriculture 



J. VAN OVERBEEK 



SYNTHETIC plant hormones have found extensive use in tropical agri- 

 culture. From the point of view of progress in research, however, 

 the accent has been far too much on use and not enough on the under- 

 lying fundamental principles. In the long run a balance between theo- 

 retical and practical knowledge must exist. It is true that at times trial 

 and error methods can yield spectacular results. Yet, sooner or later 

 "bugs" develop which can be corrected only after theoretical knowledge 

 has caught up and the principles involved are more fully understood. 



Tropical crops and plants make highly worthwhile subjects for studies 

 in fundamental plant physiology. Often physiological principles are 

 apparent in tropical plants while they are obscure in plants growing 

 under the different environment of the middle latitudes. It is no wonder, 

 therefore, that new principles are often brought to light by those working 

 in the tropics. Fitting, working in the tropics on orchids, was first to 

 reahze the existence of hormone-like substances in the development of 

 the ovary, and, as a result of these observations, to use the word hormone 

 for the first time in plant physiology (57). It was Bouillenne and Went 

 (5), again working in the tropics on tropical plants, who conceived the 

 idea that substances now known as auxins promote the initiation of 

 adventitious roots on cuttings. 



The enormous potentialities of plant physiological research in the 

 tropics is not sufficiently realized by those responsible for investing in 

 research. If money is invested in tropical research it is usually done with 

 immediate material benefits in view. However understandable this is, 

 there is a great need for the establishment of permanent institutions in 

 the tropics where plants are studied for the sole purpose of "extending 

 the horizons of our intellect" as Bronk (6) has so aptly put it. 



