DISEASES OF PLANTS. 51 



nilibrrs of commerce. Succeeding cbai)ters deal with tlie cliemicul and pliysical 

 l)roperties of rubber, vulcanization. India-rubber plantations, India-rubber sub- 

 stitutes, reclaimed rubber, washing, drying, and compounding of rubber, rubber 

 solvents and their recovery, rubber solution, and the various forms of manufac- 

 tured rubber and the articles made therefrom. Concluding cliai)ters treat of the 

 l)roduction and uses of gutta-percha and balata. A brief bibliography is also 

 given of publications dealing with the various phases of rubber cultivation and 

 manufacture. 



DISEASES OF PLANTS. 



Report of the botanist for 1907, (J. P. Clinton (Coiinrcticut ^taie Hta. Ritt. 

 19011-8, i)t. G, i>iK .^39-396, p/.s. 16). — General notes are given on a number of dis- 

 eases of plants that have been previously reported and short accounts i)re- 

 sented of a number that have not hitherto been reported as occurring in this 

 State. 



The diseases new to the State are taken up under an ali)habetical list of 

 liost plants, and among the number, attention is called to the blight of the 

 wlute pine, wliich, it is said, has been one of the most conspicuous diseases of 

 the year, occurring not only in Connecticut but over most of New England. 

 This disease has been attributed to various causes, but tlie author thinks the 

 trouble a physiological one, induced by adverse conditions. . In some cases 

 winter injury was probably the cause of the trouble, wliile in others it was 

 apparently due largely to drought and late frosts. 



Notes are given on the internal brown spot of potatoes, a diseased condition 

 that pro\ed ratlier troublesome in potatoes tliat were imported from Scotland 

 for experimental purposes at the station. The occurrence of scurf on potatoes, 

 due to SpondyJocJudiuni atrovircns, is also noted. 



An account is given of a disease of Sumatra tobacco, which is believed to 

 be possibly of bacterial origin. Attention was first called to this disease in 

 Bulletin 150 of the station (E. S. R., 17, p. 136), in which it was stated that 

 the plants were attaclced by a fungus root disease. Subsequent studies seemed 

 to indicate that the trouble may be bacterial in origin. The disease, so far as 

 it has been noticed, has been confined to seed betls. 



An account is given of investigations begun in 1906 on the root rot of tobacco, 

 due to Tluehiikt basicola. This fungus, which seems to be rather widely dis- 

 tributed, occurring on a number of plants, has proved very troublesome botli 

 in tobacco seed beds and in the fields. Experiments with formaldehyde and 

 steam sterilization in seed beds have given fairly satisfactory results, the 

 steam heated plats prtniucing the best stand, followed by those treated in the 

 fall of the year with formaldehyde at the rate of 1 part formalin to 100 parts 

 water. Formalin diluted and sprinkled over the plants after their growth had 

 begun, injured the plants and resulted in a very poor stand and growth. When 

 the convenience of treatment is considered, the author believes that tlie formalin 

 treatment is an efficient and convenient method of protecting seed beds against 

 the root rot and possibly the damping off of tobacco. Observations made of 

 the treatment of tobacco fields for the control of this disease seem to indicate 

 that as yet no effective fivatment for use in the field has been obtained. 

 \Vhere\er possililc the growing of toiiacco in land (hat has licrome infested 

 .should be abandoned for a few years. 



The report concludes with an account of sludies on hetercpcions rusts of Con- 

 necticut having a periderinium for their a'cidial stage. This Is a detailed 

 report on investigations which have been previously noted (E. S. R.. 19, p. 1149). 



Symptoms of disease in plants, F. D. Healo (Aim. R/rt- Nfbr. Hnrt. Koc. 

 38 {1007), 1)1). J31-,l'i'i), — The author describes the symptoms of a large number 



