DISEASES OF CULTIVATED PLANTS 629 



In some cases the spaces 'between petals show a whitish hyphal 

 growth plainly evident to the eye, while in other cases no hyphae 

 can be detected without a microscopic examination. When affected 

 buds are broken open, oblong watery-looking objects, 1/12 inch or 

 less in length, are found buried in the soft mass of rotting petals or 

 lying between them. These objects are the distended abdomens of 

 minute female mites, which have been found as constant accom- 

 paniments of the fungus. In the earlier stages of the rot in natural 

 infections the mites may be quite small and inconspicuous, but in 

 well-developed cases of bud-rot they are so evident that they could 

 not be easily overlooked. 



The work which has been carried out up to the present time 

 leads to the conclusion that the disease can be prevented or eradi- 

 cated if the following measures are carefully heeded : 



1. Practice clean culture with the destruction of all refuse that 

 might offer a temporary lodging place for either fungi or mites. 



2. Keep the moisture down to the minimum necessary for the 

 healthy growth of the plants. 



3. Pick off all affected buds as soon as they appear and destroy 

 by burning. Do not under any conditions throw them down on the 

 benches. The benches should be gone over at least every other day 

 until the disease is thoroughly under control. (Neb. E. S. B. 103.) 



Leaf and Calyx Mold (Fairy Ring). This is often very un- 

 sightly upon the calyces and pedicels of these flowers ; it also attacks 

 the leaves. All sorts appear to be more or less parasitized with the 

 fungus in the houses where it prevails. Yet another spotting is pro- 

 duced by the carnation leaf -spot fungus (Septori Dianthi), which 

 has appeared at this Station more frequently upon the Daybreak 

 variety. It is believed that both these fungi will yield to treatment 

 with Bordeaux mixture as per calendar. 



Carnation Rust. This rust fungus is one of the serious dis- 

 eases of the carnation. There is some difference in the liability of 

 varieties to the disease, and perhaps a much larger difference in the 

 condition of the stock plants from which cuttings are made. As- 

 suredly this matter of cutting stock is of very great importance and 

 one admitting of selection of the very best plants. Experiments 

 conducted at this Station in 1896 yielded no gain from spraying 

 with Fowler's solution, which has been sometimes recommended. 

 Watchfulness in the destruction of rusted parts, and in the stock for 

 propagation, are suggested for the control of rust. 



A Root- or Stem-Rot. This has been noted by Stewart, and oc- 

 casional rotting of the flowers through the presence of a Botrytis. 

 For the former no thoroughly effective remedy is now at hand, while 

 general cleanliness of the house is necessary to avoid the rot fungus 

 Botrytis. 



CANNA. 



Rust. Foliage of canna is sometimes attacked by a rust which 

 may be identified by the characters of its fungus (Urcdo cannac). 

 -(Ohio E. S. B. 214.) 



