654 EXPERIMENT STATION RECORD- [Vol.41 



DISEASES OF PLANTS. 



Pan American cooperation in plant quarantine, R. Sundbekg (Proc. 2. Pan 

 Amer. Set. Cong., 1915-16, vol. 5, pp. 869-874)- — An outline witli discussion is 

 given of conventions and otlier steps taken in preparations regarding quaran- 

 tine as looking to tlie protection of plants against parasites. 



Pan American cooperation in plant quarantine, C. L. Maelatt {Proc. 2. 

 Pan Amer. Sci. Cong., 1915-16, vol. 3, pp. 888-90^). — Ttiis completes the series 

 of whicti tlie foregoing has been noted, and includes the discussion which fol- 

 lowed. 



Phytopathological inspection of horticultural and viticultural establish- 

 ments (Bui. Mens. Off. Renseig. Agr. [Paris], 16 (1917), Apr.-June, p. 262). — 

 The number of establishments engaged in viticulture or horticulture submit- 

 ting to phytopathological inspection is said to be increasing steadily, the num- 

 bers thereof being S3 for 1914, 103 for 1915, and 132 for 1916. The values of 

 exports also show a steady and substantial increase, which is attributed to the 

 greater assurance of safety conferred by observance of the regulations and 

 precautions regarding inspection. 



Seed and soil treatment for vegetable diseases, M. T. Cook (New Jersey 

 Stas. Circ. 106, pp. 4, flff- i)- — Specific directions are given for the control of a 

 number of seed-borne diseases, and suggestions are made for soil sterilization 

 by tlie use of formaldehyde and steam. 



[Work done in plant pathology], G. H. Coons (Michigan Sta. Rpt. 1918, pp. 

 273-276). — An outline is given of work in progress in plant pathology at the 

 station, the principal investigation being of diseases of potato, celery, cereals, 

 beans, and muck crops. 



In connection witli the potato disease work it has been found tliat the times 

 of treatment with formaldehyde and corrosive sublimate can be shortened from 

 the 1^ to 2 hour period commonly recommended to 15 minutes for formalde- 

 hyde and 30 minutes for corrosive sublimate, and still obtain efficient di-sease 

 control. In the study of the control of cereal diseases by the use of formalde- 

 hyde, as a result of field laboratory and greenhouse tests, the author claim.s 

 that concentrated formaldehyde when applied according to directions does not 

 injure germination, and that where injury occurs it is brought about either from 

 failure to follow directions as to dosage or time of covering, or from allowing 

 the grain to stand too long before planting. Experiments have proved that com- 

 plete removal of formaldehyde from grain is not possible by airing under 

 ordinary conditions. A recommendation is made for immediate planting after 

 treating seed. 



[Report of the department of] botany, G. M. Reed et al. (Missou7-i Sta. Bill, 

 163 (1919), pp. 31-83).— A progress report is given of investigations on the 

 physiological relation of powdery mildews to their host plants, forest tree 

 diseases, systematic and physiological studies of rusts, grain smuts and their 

 conti'ol, and a watermelon disease said to occur in southeast Missouri, the lines 

 of work and results described following quite closely those previously given 

 (E. S. R., 38, p. 645). 



Practically all varieties of oats and barfey have been found susceptible to 

 their respective mildews. Very few varieties of oats have been found that are 

 not susceptible to crown rust when grown under greenhouse conditions. Inocu- 

 lation experiments with sorgluim smut have again shown that the milos are 

 free from snmt and feterita only slightly infected. Other varieties of sorghums 

 vary in the proportion of infection. Oat varieties were found to differ widely 

 in respect to infection by Vstilago avenw and U. levis. Seed treatments with 



