PREFACE 



Vegetable forcing occupies an important place in 

 American horticulture. The subject is taught to large 

 numbers of students, and it has enlisted the interest of 

 thousands of gardeners who are attracted by the idea of 

 growing vegetables under artificial conditions. To meet 

 the needs of these two groups of people has been the 

 constant aim of the author. 



The treatise is necessarily condensed. It has not 

 seemed expedient to enter into a lengthy discussion of 

 subjects naturally belonging to the entomologist, plant 

 pathologist, botanist or chemist. This would necessarily 

 result in the overlapping of college courses and in trying 

 the patience of practical growers who want merely a 

 working knowledge of the principles and practices in- 

 volved in the production of the various forcing crops. 



Frequent visits have been made to the most important 

 vegetable forcing centers of the United States. Many 

 bulletins of the agricultural experiment stations and of 

 the United States Department of Agriculture have proved 

 to be of great value as sources of information. Special 

 mention should be made in this connection of the Market 

 Growers' Journal, and of courtesies extended by its mana- 

 ger and editor, Sam W. Severance. 



The preparation of the manuscript would not have been 

 possible without the assistance of scores of friends. Ex- 

 tensive correspondence was conducted with numerous 

 growers, teachers and investigators, and I desire to thank 

 all of these friends for their most valuable co-operation. 



The author is particularly indebted to Prof. J. R. Bech- 

 tel of The Pennsylvania State College, and to Prof. C. W. 



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