﻿STUDIES OF THE PINK BOLLWOEM IN MEXICO 



59 



made to do the work on a conmiercially profitable basis. On the 

 contrary, the plan followed was to keep the plants thoroughly covered 

 with poison during the entire period of treatment. Some of the 

 plats were dusted with hand guns and others with 2-row mule dusting 

 machines. 



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Fig. 15.— Progress of the infestation of green bolls in poisoned and check plats as shown by weekly 

 examinations, 1921 poison tests 



The air in the Laguna district is very dry and there is considerable 

 wind. It was therefore found that applications must be made every 

 five days in order to keep the plants fairly well covered with poison. 

 Aj^fjlications were repeated alter rains. A period of calm lasting 

 an liour, more or less, usually occurs at 5 or 6 o'clock in the morning, 

 and the applications were inad(; at that tinuj. Dow was usually 

 absent or so light as to be hardly noticeable. The conditions for 

 dusting were therefore far from ideal. 



The 1921 plats may be divided into three groups. Poisoning on 

 ihose of the first grrnip (plats 2, 0, 10, and 14) began about the middle 



