Diseases and Injuries 



masses of a species of Fusarium. Many of the worst affected leaves were dying. The 

 Fusarium was evidently parasitic on the leaves, but a careful examination revealed the 

 fact that in every case the spots originated in a rust sorus'. It appeared that the Fusarium 

 was unable to attack the uninjured leaf, but when the epidermis was broken by rust it 

 was able to enter and bring about decay of the leaf tissue. It is improbable that the 

 Fusarium is parasitic upon the rust. 



"The writer has occasionally observed Fusarium attacking injured leaves and stems 

 of carnations and the spore masses of a similar Fusarium are common on the stems of 

 carnations affected with that form of stem-rot commonly known as dry rot or die back ; 

 but we have never before known Fusarium to produce a genuine leaf-spot of carnations. 

 Inoculation experiments may show that this Fusarium is identical with the one causing 

 carnation stem-rot." 



Remedies and Preventives for Stem Rot 



The soil in which carnations are grown through the summer should be 

 frequently changed, and under no circumstances should carnations be planted 

 in the same soil year after year, wherever it is possible to avoid it; but, 

 instead, a new location should be chosen annually. Sterilizing the bench, 

 potting soil, and propagating sand should be thoroughly done, and should be 

 persisted in until the disease is overcome. 



In the preparation of bench or potting soils, too much decaying nitro- 

 genous matter should not be used; and the soil should invariably be fresh, 

 clean, and well decomposed. Under no circumstances should rank, fer- 

 menting manures be introduced into the soil. It is important that the 

 soil in the benches be kept sweet, and in a friable, healthy condition, by 

 close attention to watering. As cool a" temperature as possible should be 

 maintained after the plants are benched, and until growth is fully established. 

 The Stem Rot usually disappears, to a large extent, upon the advent of cold 

 weather in the fall, thus indicating that the fungus flourishes best in a high 

 temperature. 



So far as I have been able to study Stem Rot in the field, it occurs 

 immediately after the intense heat which we usually have in July and August, 

 and sometimes in September. When we have had a lengthy spell of ex- 

 tremely hot weather, with frequent thunder showers and steaming, hot 

 cloudy days, the Stem Rot seems to have developed to its greatest extent, 

 and caused the greatest damage. Such weather sometimes induces the 

 rotting of potatoes, squashes and melons in the field ; also cabbages and cauli- 

 flower ; the disease being called "gangrene" by the growers of the latter crops. 



In my opinion, Stem Rot may be largely avoided by propagating from 

 strong, healthy stock plants, and by close observation of sanitary conditions 

 when rooting cuttings ; also by proper treatment of the young stock while 



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