99 



Fig. 113. Fungus elements found 

 about the roots of larkspur suffer- 

 ing from a fatal disease of the 

 roots. 



just where it left the ground and below that point, so that the tissues 

 were easily poked apart with the finger, and the interior of the base of 

 the stalk was seen to be affected with a similar looking fungus growth. 

 The threads in the soil and the mycelium inside the tissues of the stalk 

 were composed of similar elements, as 

 shown by the sketches. 



Although the stalk for an inch or two 

 above ground appeared to be discoloured, 

 it was not soft and rotten as was the por- 

 tion below ground, nor on examination 

 could any fungus elements be found in 

 the tissues. The hollow of the stalk, 

 which appeared to be a likely place to look 

 for signs of the disease, showed no traces. 



It appears that the manner of attack 

 is to destroy the bark and subjacent 

 parenchyna near the surface of the ground. 

 In other words, the disease produces a kind 

 of girdling or collar rot, or root rot. 



Lime at the rate of at least one ton per 

 acre is recommended for such attacks. 

 Trenching off the diseased area so as to isolate it was also suggested. 

 The details of these remedies are given on page 983, October number 

 of this Gazette. 



Leaf Disease of the Chrysanthemum. 



This is a disease of the Chrysanthemum that attacks the leaves 

 principally, the plants sometimes dying from the effects of the attack. 

 The lower leaves succumb first, and thence the disease travels upward ., 



The principal symptoms are seen on the leaf blades, which turn 

 yellow and then brown, either in spots or all over. The colours change 

 from the normal green, first to Naples yellow, then gradually through 

 light brown to dark brown. 



The fungus causing the disease is a species of Septoria, produced in 

 perithecia so small that even with a magnifying glass it is not easy to 

 see them. On leaves where the spores were 

 so numerous as to be found in great numbers 

 in every water preparation made from pieces 

 of leaf five millimetres square, the pustules, 

 which must have been very numerous, 

 were to be seen only with difficulty. _ 



Remedies. I have had no opportunity to t$e ehrysanthe 



test the effects of fungicides on this pest. 

 It is known that a similar disease of the 

 tomato can be easily controlled by the 

 thorough use of Bordeaux Mixture. I have 

 seen only one case of this disease, and in 

 that case the plants were killed. The 

 disease seems uncommon, but it must be remembered that 

 florists do not make such frequent calls upon the resources of the 



oria of 

 emum. 



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