438 BOARD OF AGRICULTURE. [Pub. Doc. 



THE PREVENTION OF FUNGOUS DISEASES PECULIAR 

 TO GREENHOUSE PLANTS. 



BY DR. GEORGE E. STONK, TRx >FESSOR OK BOTANY, MASSACHUSETTS 



AGRICULTURAL COLLEGE. 



The diseases to which plants are subject under glass require 

 dilterent methods of prevention than those in conniion use 

 out of doors, since in greenhouses the cro}) conditions are 

 largely under control, whereas in outdoor crops they are left 

 to tlie mercy of the Aveather and the whims of the season. 

 To meet the unforeseen seasonal conditions to wliich outdoor 

 crops are subject it is necessary to resort to methods of pre- 

 vention each year. Such methods consist of spraying crops, 

 or appl^dng other treatments before certain pests have made 

 their appearance. There is, however, very little need of the 

 application of spra3dng mixtures to greenhouse plants, since 

 the conditions which give rise to diseases can be and are 

 controlled by expert gardeners to a very large extent. The 

 recommendations, therefore, for a general system of spmying 

 for indoor crops, such as is expedient at the present time for 

 outdoor crops, would be irrational, and would constitute a 

 step in the wrong direction. Ever}^ skilled and intelligent 

 gi'ower realizes this, and the more skilled a gardener is, the 

 fewer diseases he has to contend with. The gardener who 

 can turn out a nearly perfect crop as regularly as a manufac- 

 turing establishment turns out its jn'oducts is (|ualified for 

 the severest tests of proficiency. 



The increased i)roduction of high-grade greenhouse prod- 

 ucts in Massachusetts has been the means of training and 

 develo})ing a large class of men as etiicient growers, and with 

 this increased skill and knowledge there has come about a 

 better understanding of the causes of diseases and methods 



