348 EXPERIMENT STATION EECORD. 



United States and supplements the volume by Stevens and Hall on Diseases of 

 Economic Plants (E. S. R., 24, p. 345), in which the authors describe the gross 

 characters of various diseases. 



In the present publication technical descriptions are given of the different 

 fungi, and keys presented whereby the student can determine the specific 

 relationship of any parasite known to occur on economic plants in the United 

 States. Some species have been included that have not been reported as present 

 in this country and some nonparasitic ones are included in the keys, but no 

 attempt has been made to give complete lists of all of them. The arrangement 

 of the material is by orders, beginning with the slime molds, Myxomycetes, 

 and running through the Schizomycetes and true fungi, the Eumycetes. 



Extensive bibliographies are given at the end of the various groups, and a list 

 of books and periodicals that are thought to be useful for students of plant 

 diseases is also included. 



Keport on economic mycology, E. S. Salmon {Jour. Southeast. Agr. Col. 

 Wye, 1912, No. 21, pp. 321-404, pis. 25, figs. 8). — Reports are given of observa- 

 tions on miscellaneous plant diseases, celery blight and its prevention, some 

 spraying experiments for the control of apple scab, and notes on the American 

 gooseberry mildew. In addition the author and assistants report on the Cyto- 

 spora disease of the cherry (see p. 352), experiments with Rliizopus nigricans 

 on tomatoes (see p. 351). and a new disease of apple buds (see p. 352), as 

 well as on the lime-sulphur wash for use on gooseberries, previously noted 

 (E. S. R., 29, p. 249). 



Among the miscellaneous diseases reported upon, attention Is called to the 

 crown gall of alfalfa due to Urophlyctis alfalfce, a number of minor diseases of 

 fruits, and tomato canker due to Botrytis, the superficial appearance of which 

 resembles that caused by Mycosp7ia?rella citrulUna. In a previous publication 

 (E. S. R., 23, p. 337) attention was called to the advantage of the presence of 

 male hops in the control of hop mildew. Subsequent Investigations have con- 

 firmed the previous conclusion that by the fertilization of the hop the growing 

 out is hastened and the critical period when the hops are subject to mildew is 

 shortened. 



Experiments are reported on the spraying of celery for the prevention of the 

 blight due to Septoria petroselini apii, from which it is concluded that three 

 sprayings with home-made Bordeaux mixture, 4 : 4 : 50, will protect celery 

 plants during the growing period. As the disease is liable to occur early in the 

 season it is recommended that seedling plants be dipped in Bordeaux mixture 

 at the time of transplanting. 



For the control of apple scab, experiments were conducted on the use of Bor- 

 deaux mixture, lime sulphur, and iron sulphid as fungicides. Comparisons 

 were also made between Bordeaux mixture (4 : 4 : 50) and the Woburn mix- 

 ture, which is a greatly diluted form of Bordeaux mixture. It was found that 

 for most varieties of apples home-made Bordeaux mixture could be success- 

 fully employed for the control of the scab, although it has proved injurious to 

 some varieties. The Woburn Bordeaux mixture did not prove as effective as 

 the ordinary Bordeaux mixture. Lime sulphur as a fungicide was found to 

 check slight attacks of scab, but attention must be paid to the strength of the 

 solution, many varieties being injured where the specific gravity was 1.01. For 

 varieties known to be subject to injury, it is recommended that lime sulphur 

 with a specific gravity of 1.005 be tried. The self-boiled lime sulphur and iron 

 sulphid wash gave some very satisfactory results, and it is thought that this is 

 worthy of further trial. The self-boiled lime sulphur and copper sulphid prep- 

 aration is also believed worthy of further test. 



