1g Wal 
FOREWORD 
Since Dr. Bewley left the Rothamsted Experimental 
Station to proceed to the daughter station at Cheshunt 
he has had unrivalled facilities for studying the diseases 
of the plants grown under glass in that area. Few 
people realize the highly specialized nature of the market 
garden glasshouse industry in the Lea Valley, or the 
extraordinary skill of the more successful of the growers 
engaged therein. The traveller to Cambridge on the 
London and North Eastern Railway line sees a multitude 
of glasshouses between Enfield and St. Margaret’s, but 
probably does not know that here are grown the bulk 
of the English tomatoes and cucumbers which find their 
way to the London markets and the industrial regions 
of the North, and that here too the growth of plants is 
carried out to so high a level of efficiency that growers’ 
have actually sold palm-trees to Africa and peaches to 
New York. 
Naturally, enterprises of this sort are possible only 
to those with keen powers of observation and a sound 
instinct for the growth of plants. Among these men 
there is a great body of empirical knowledge which 
Dr. Bewley has been able to explore. Further, he has 
been able, at the Experiment Station at Cheshunt, 
to test thoroughly whatever seemed worth following up, 
and from his own investigations he has succeeded in 
elucidating much that was shrouded in mystery. 
The book thus combines the best empirical knowledge 
of the grower with the results obtained by the scientific 
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