I*. A. van dee But 269 



Stewart 1 writing in lS'.IS states that under the popular nanus 

 "Stem-rot" and "Die-back" have been confused two distinct diseases 

 in carnations. 



The one due to Rhizoctonia causes plants to wilt suddenly by rotting 

 of the stem at or just below the surface of the soil. The cortex of 

 diseased plants separates readily from the wood, the pith is attacked quite 

 easily, becoming water-soaked in appearance and filled with fungous 

 hypliae. 



The other, caused by a Fusarium sp., attacks chiefly the stem and 

 larger branches, discolouring the wood and killing the cortex but 

 rarely causing a soft rot. The affected plants die gradually with yellow- 

 ing or drying of the foliage. The fungus rarely fruits on the outside 

 of the stem but does so frequently in the cambium and pith of stems 

 long dead. Stewart 2 has also described a leaf -spot disease in carnations 

 caused by a Fusarium sp. Of this disease he says : "A bunch of carna- 

 tions of the variety Emily Pierson was quite seriously affected Avith 

 a peculiar leaf spot, the spots varied in length from $— 1 in. The smaller 

 ones were elliptical but the larger ones occupied the entire width of 

 the leaf and were irregular at the ends. They were covered with a 

 pinkish-grey mold and irregularly dotted at the centre with the light 

 yellow spore masses of a species of Fusarium. Many of the worst 

 affected leaves were dying." The author found the Fusarium always 

 originating in a rust pustule and, though not capable of infecting 

 uninjured leaves, readily entering through the epidermis which had 

 been broken by the rust fungus, and bringing about decay of the leaf 

 tissue. He further remarks that inoculation experiments may show 

 this fungus to be identical with the Fusarium causing stem-rot in 

 carnations. 



In conclusion, he states that the carnations were grown under 

 conditions exceptionally favourable to the attack of fungi, but they 

 did well and were free from disease with the exception of the Fusarium 

 leaf spot and a moderate attack of rust. 



The disease herein described has much in common with the "die- 

 back" or "stem-rot" disease of Sturgis 3 . It, too, is caused by a 

 Fusarium sp., but whether it is the same species in the two instances 



1 Stewart, F. C, "Stem Rot Diseases of Carnations," Exp. Station Records, 1898-99, 

 Vol. x. 



2 Stewart, F. C, "A Fusarium leaf-spot of Carnations." N.Y. (Geneva) Agric. Exp. 

 Station Bull. 164, p. 219, Dec. 1899. 



s Sturgis, Wm. C, op. cit. p. 1. 



