OIHSR DISEASES. 34S 



DraEASES OP THE OHBTSANTHEMUM. 



This plant is subject to the attack of several forma 

 of what are commonly called "leaf-spot." In two of 

 these forms, which the botanist calls Septoria Chrysan- 

 themi, E. and D., and Vylindroisporium Chrysanthemi, 

 E. and D., the first appearance is as small brown spott.; 

 which quickly enlarge until they cover considerable areas, 

 when the leaves turn yellow and drop. In anothsr form 

 {Phyllosticta Chrysanthemi, E. and D. ), the spots have 

 more of a reddish color and seem quite velvety. If 

 there are many of these spots upon a leaf, the portions 

 between them turn yellow and the leaves droop. 



The Bordeaux mixture is one of the most effectual 

 remedies and if the disease appears when the plants are 

 small, it should be used frequently. Although less 

 effectual, if the use of a fungicide is necessary after the 

 flowers open, cupram, or some of the other solutions, 

 should be used instead. Infected leaves should be at 

 once picked off and burned, and if the plants are badly 

 injured it will be best to throw them out at once. Cut- 

 tings for a new stock should be selected only from 

 healthy plants and should be frequently sprayed. 



The chances of injury from these diseases will be 

 greatly lessened, if mineral manures, such as wood ashes 

 and ground bone, are freely used. Keeping the houses 

 cool and well ventilated, and, if the plants are very thick, 

 the removal of some of the lower leaves from plants 

 growing closely in beds, will aid in keeping off the disease. 



A MIGNONETTE DISEASE {Cercosporu Resedw). 

 In the American Florist for September, 1887, Pre- 

 fessor Sejmiour figured and described a disease of the 

 mignonette, which has become quite troublesome in some 

 sections. The first sign of the disease is a reddish dis- 

 coloration, which spreads over the leaf and is followed 

 by the appearance of small, sunken spots with yellowish 



