Diseases and Injuries 



not usually so well marked as on the leaf. As a rule, this disease is 

 developed by improper treatment of plants. It also frequently develops upon 

 plants in the open field, when a hot, dry season is followed by a continuous 

 spell of wet, cold weather; and, then again, by periods of intense heat. It 

 may also be easily developed upon freshly transplanted plants, by over- 

 watering and over-spraying the plants before root action is fully established, 

 and by leaving the foliage wet over night, especially where the night tem- 

 perature is allowed to fall considerably below 45 degrees. 



As a rule, where carnation plants are properly watered and abundantly 

 ventilated, this disease will not prove serious. The same spraying which 

 has been recommended for Rust will usually arrest, or prevent, the spread 

 of the Spot; and the same treatment as to keeping the plants in vigorous 

 growth, and also the atmosphere in a pure condition, is recommended. 



Fairy Ring Spot (Heterosporium echinulatum) 



This fungus, which was imported from Europe about the year 1892 

 or 1893, has been known for nearly a quarter of a century in England. In 

 appearance, it differs from Septoria Dianthi in that the vegetable threads, 

 growing within the leaf tissue, exhaust the substance at certain points, so 

 that there appears a nearly circular, light-colored spot. The spores are 

 brown in color, and when produced in great numbers, with the threads, 

 darken the spot. At this stage, the spot possesses different shades of color, 

 according to the number of spores produced. The growth of the fungus 

 from the center of the spot is centrifugal, and the darker color is apt to be 

 arranged in concentric lines, or rings, representing a miniature fairy ring 

 hence the name. 



This fungus is much more injurious to the carnation than the Septoria 

 Dianthi, as it spreads more rapidly and destroys the foliage to a greater 

 extent ; in fact, I have many times seen the greater part of the foliage taken 

 from plants by this disease. 



The same conditions that bring on attacks of Septoria will favor the 

 development of the Fairy Ring, and the same remedies are also recom- 

 mended. 



Stem Rot (Rhizoctonia) 



Probably the most insidious and destructive of the various fungous dis- 

 eases known to carnation growers is Stem Rot (Rhizoctonia). This disease 

 has been known to the American grower for many years, but until within 

 a recent period, it appeared in its destructive form only at rare intervals. 



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