650 EXPERIMENT STATION RECORD. [Vol. 43 



noted (E. S. R., 42, p. 350) regarding the overwintering of Peronosporacese 

 by means of spores in or on seeds, tlie author made some observations during 

 1919, which as liere noted are considered to show tliat so far as Peronospora 

 parasitica and P. aUinearum are concerned, seed three years old are safe as 

 to infection of the young plants. 



The comparative efficacy of ordinary and casein Bordeaux mixture for 

 tlie i>reservation of grapes, Vkrmorel and Dantony {Conipt. Rend. Acad. 

 Sci. [Paris], 169 {1919), No. 9, pp. 439, JfJfO).— From worli briefly described, it 

 is concluded that casein is an important addition to Bordeaux mixture, in- 

 creasing the spreading and uniformity of distribution over all the surface 

 of the organs treated. The copper compounds remain in place in spite of 

 rains without loss of solubility. 



Avocado diseases, H. E. Stevens {Proc. Fla. State Hort. Soc, 31 (1918), pp. 

 57-73). ^Among the troublesome fungus diseases of avocado in different coun- 

 tries, rusty blight, root rot, and anthracnose are regarded as the most seri- 

 ous. Tlie first two named are not known to occur in Florida, but injury has 

 been caused by anthracnose or closely related diseases. Leaves and fruit 

 are attacked by a fungus supposed to be a Gloeosporium. A Colletotrichum 

 is often found on diseased leaves and frait spots. This is controlled by timely 

 use of Bordeaux mixture. 



Of two apparently new and undescribed diseases, one is a fruit spot. The 

 other, primarily a disease of young tender foliage and named avocado scab, has 

 been proved by a series of experiments to be caused by the same fungus as 

 that producing citrus scab {Cladosporium citri). 



Some disease problems of tlie season, H. E. Stevens {Proc. Fla. State 

 Hoii. Soc, 30 {1917), pp. 37-43).— This includes discussion of the direct and 

 indirect effects of cold on citrus trees and their performance; also of citrus 

 scab {Cladosporium citri), melanose {Phomopsis citri), and withertip {Col- 

 letotrichum gloBOsporioides) . 



Spraying for citrus diseases: Its usefulness and its limitations, R. R, 

 Fulton {Proc. Fla. State Hort. Soc, SO {1917), pp. 60-65).— A brief review is 

 given of the possibilities and limitations of methods indicated for control of 

 such citrus diseases as scab, melanose, and withertip or anthracnose. 



Report of citrus canker committee, D. C. Gillett et al. {Proc Fla. State 

 Hort. Soc, 30 {1917), pp. 51-59). — An account is given of measures and related 

 activities looking to eradication of citrus canker in Florida. 



Citrus canker condition, F. Stikling {Proc Fla. State Hort. Soc, 30 {1917), 

 pp. 48-50). — A brief account is given of the work looking to the eradication of 

 citrus canker since May, 1914, when it was definitely known that the disease 

 was present in Florida. 



Citrus canker eradication, N. D. Zuber {Ann. Rpt. Commr. Agr. Tex., 11 

 {1918), pp. 4^-49) ■ — In this portion of the orchard and nursery inspection re- 

 port, it is stated that citrus canker eradication work has been carried on 

 actively in collaboration with the Bureau of Plant Industry, U. S. Department 

 of Agriculture. The State is divided into 11 districts, bordering largely on 

 the Gulf, and inspections of citrus trees are made at intervals of two to six 

 mouths according to location. Statistics are given of the work during the 

 fiscal year. 



Pear blight control work has also been continued, and statistics are given 

 of these activities. 



Behavior of tlie citrus canker organism in the soil, H. A. Lee {Jour. Agr. 

 Research [U. S.], 19 {1920), No. 5, pp. 189-206, pis. 2).— In an investigation 

 carried on under the auspices of the Bureau of Plant Industry, U. S. Depart- 



