Preface 



The Fourth International Conference on Plant Growth Regulation 

 was held at the Boyce Thompson Institute for Plant Research in 

 Yonkers, New York, from August 10 through August 14, 1959. The 

 Conference was sponsored jointly by the Boyce Thompson Institute, 

 The New York Botanical Garden, and the Brooklyn Botanic Garden 

 through an Organization Committee headed by Dr. George L. 

 McNew, Managing Director of the Boyce Thompson Institute. 



One hundred and forty scientists from eighteen countries were 

 invited to participate through the presentation of formal papers, in 

 organized discussion groups, or via informal question and answer 

 periods. This volume reports the proceedings of the Conference. 



The program was arranged by a committee headed by Dr. A. J. 

 Vlitos, who first suggested the Conference. Housing, transportation, 

 and the memorable luncheons and dinners were handled by other 

 committees. 



An international conference of this size is an expensive undertak- 

 ing requiring funds to assist participants who came from abroad, to 

 cover the costs of food, transportation, and the many other obliga- 

 tions which had to be met. Our desire to hold the cost of this book 

 to a reasonable figure meant it had to be subsidized. Financial sup- 

 port was generously provided by The Rockefeller Foundation, the 

 National Science Foundation, and the following corporations. 



Amchem Products Co., Agricultural Chemicals Division, Ambler, Pennsylvania. 



American Cyanamid Co., Stamford, Connecticut. 



Chas. Pfizer and Co., Brooklyn, New York. 



Diamond Alkali Co., Cleveland, Ohio. 



The Dow Chemical Co., Agricultural Chemicals Laboratory, Midland, Michigan. 



[ix] 



