﻿534 Dodge: Effect of host on Gi-mnosporaxgium 



{Gymnosporangium hiseptatum) is capable of infecting Aronia 

 was next considered. Small plants of Aronia and Amelanchier 

 were in excellent condition at this time and the supply of teleuto- 

 spore material from Lakehurst, New Jersey, was unlimited. The 

 infection frame was used so that the different species of trial host 

 could be subjected to the same conditions. Several branches bear- 

 ing telia were hung about in the frame, and the plants were sprayed 

 with large quantities of sporidia. Whenever Aronias were inocu- 

 lated (except on April 15) one or more plants of Amelanchier were 

 also used as controls. Table V also includes the results of experi- 

 ments carried out in 1914. The teleutospore material used April 

 13-16 was obtained from Newfield. 



[ (Gymnosporangium I 



- .-;:;■■•„ ^,i";'r{^-— 's^-r 



^ 



Apnls A. intermedia i 



^ 



I tIZifolia \ I : : 



' l^'^ifoUa \ \ ; I 

 |A.nya ^ ; 3 : 



Ia ir^'^ ^ ^' \ " 



lA'.^Mfolia 3 ! 

 \A.atropurpurea\ i 



A.Zf^tifolia 1 il 

 lA.atropurpurea\ i 1 



3 



Total .1 Amelanchier 1 31 ' .8 1 3 i Aronia 1 0. 1 



95 



Some of the Aronias employed in making these tests were 

 used over again for the second or even the third time. The first 



