DISEASES OF PLANTS. 571 



conducted at the New York State Station (E. S. R., 9, p. 762), are 

 reviewed. The hitter seemed to indicate that for the prevention of 

 this disease the use of fungicides was valuable, although the increased 

 yield did not justify the expense. 



An account is given of a badly infested plat of vines, in which severe 

 pruning, followed l)y thorough cultivation and throwing the dirt over 

 the diseased stems, resulted in an excellent growth of young shoots 

 nearly free from the disease. As a possible explanation for this, it is 

 stated that the diseased canes were largely removed l)y the pruning, 

 and an unusually dry season prevented the development of the fungus. 



White rot of the grape, L. Ravaz {Prog. Agr. et Vit. {ltd. VKst), 

 '21 {1900), No. 37, pp. 3So-3S7,p>l. i).— This disease is said to be due 

 to the fungus Coniothyrium diplodiella or Charrinnia diplodiella. 

 The fungus is considered as a semiparasite, being incapable of invad- 

 ing sound tissue, but whenever by accident the epidermis of the 

 grapes is broken it readil}^ attacks and destroys the fruit. This 

 disease is said to be a quite common accompaniment of hailstorms, the 

 hail injuring the grapes and permitting the entrance of the fungus. 

 Experiments with fungicides for the prevention of the disease have 

 shown that the spores of white rot will germinate in much stronger 

 solutions of copper than those of the black rot, on which account any 

 fungicide should be considerably stronger. As this fungus is depen- 

 dent upon external agencies for its infection of the grape, preventive 

 treatment can not be recommended as in the case of other diseases. 

 It is stated that this fungus, unlike the Botrytis which causes the gray 

 rot of grapes, does not produce an}^ oxidizing diastase which is con- 

 sidered the cause of the condition of wine known as "casse." 



Stem-rot disease of carnations, W. E. Brixton ( Connecticut State 

 Sta. Rj>t. 1899, pt. 3, pp. ^i^-^5<S^).— This disease was previously 

 described by the author (E. S. R., 10, p. 262), the cause being deter- 

 mined to be a species of Fusarium. Other investigators have recorded 

 similar diseases of cotton, tomatoes, nuiskmelons, and watermelons. 

 In 1897 the author found snapdragon plants affected by a similar dis- 

 ease. In 1898 asters were similarly affected, so that it seems probable 

 that carnation, snapdragon, and aster plants are attacked by the same 

 or closely related organisms. 



The methods by which the spores are wintered over and the infec 

 tion of the plant are unknown. Attempts to inoculate healthy plants 

 above ground have failed, while seemingly healthy plants one after 

 another became diseased in a field as well as after being set in the 

 forcing-house benches. On account of the extreme susceptibility of 

 the variet}', William Scott, this was discarded. 



A series of culture experiments was conducted, in which the soil 

 was removed from around plants to a depth of about 2 in. After the 

 stems had become dry, they were coated with Bordeaux mixture, and 

 the soil replaced. From time to time a number of plants were noticed 



