PREFACE 



The world never has faced a greater shortage of 

 food than to-day. War's destructive agencies have 

 added themselves to our old invisible foes, namely 

 parasitic and disease-produdng bacteria and fungi. 



More than half of our diet is made up of vege- 

 tables. They furnish the necessary food btilk which 

 the body requires, supply important nutritive ele- 

 ments, and act as stimulants to a better blood circu- 

 lation. According to the Thirteenth Census of the 

 United States the area devoted to truck crops in the 

 United States in 1909 was estimated at 7,436,551 

 acres. The total money value of the truck crops 

 grown on this acreage was estimated at $301,104,144. 

 The crops thus estimated included asparagus, beans 

 (green), beans (dry), beets, cabbage, cauliflower, 

 com (pop and sweet), cantaloups, carrots, celery, 

 chicory, cucvunbers, egg plant, horse-radish, kale, 

 lettuce, mint, okra, onions, parsley, parsnip, peas 

 (green), peas (dry), peppers, pumpkin, radish, 

 rhubarb, rutabagas, spinach, sprouts, squash, svm- 

 flower, sweet potato and yam, tomatoes, turnips, and 

 watermelon. 



We scarcely realize the large sums of money which 

 the trucker loses annually from specific plant dis- 

 eases, because there are few available data as to 



