BUREAU OF PLANT INDUSTRY. 397 



Spraying demonstrations. — Successful work in spraying has been 

 continued by Prof. Charles Brooks, who was appointed to fill the 

 vacancy caused by the resignation of Mr. W. M. Scott. This work 

 is along essentially the same lines and will be extended. 



Fungicides. — The lime-sulphur solution has proved to be wonder- 

 fully successful as an apple spray for the earlier treatments, but 

 not satisfactory for certain diseases, like bitter-rot and blotch of the 

 apple and black-rot of the grape. Rapid progress has been made in 

 determining the limitations of the lime-sulphur solution and the 

 special advantages of using it and Bordeaux mixture for certain 

 diseases. 



Physiological diseases. — The attacks of physiological diseases 

 that began in the spring of 1911 continued to be severe throughout 

 the season. They seriously affected the crop of apples and resulted 

 in loss of many trees in the Western States. Investigation of the 

 pathological phases of these problems has been taken up, and Mr. 

 W. S. Ballard has devoted a large proportion of his time to it. 

 Rosette, chlorosis, and related diseases have continued to be severe 

 on the apple, peach, apricot, and grape in large sections of the arid 

 and semiarid parts of the United States. 



Pear-blight eradication. — The work of eradicating pear-blight 

 in the Western States has been continued. A form known as collar- 

 blight on the apple has been given particular attention in Virginia, 

 West Virginia, Maryland, and Pennsylvania, where it is very severe 

 on the Grimes Golden. Eradication experiments and demonstra- 

 tions are being carried on to combat this disease. 



Cedar rust. — The fungus causing cedar rust or orange rust of the 

 apple, being greatly influenced by climatic conditions, again became 

 a serious pest in 1912. The disease was reduced but not entirely pre- 

 vented by the destruction of cedar trees. Demonstrations have shown 

 that three applications of lime-sulphur solution at the proper time 

 will control the disease. 



Nut diseases. — The entire time of one assistant, Mr. F. V. Rand, 

 is now devoted to the study of nut diseases. The fungus causing 

 pecan rust has been described and named and successful treatment 

 demonstrated. Other diseases of the pecan are also under investiga- 

 tion, including the physiological disease known as pecan rosette, in 

 Florida, Georgia, and other Southeastern States. Studies of other 

 nut diseases, such as those of the native black walnut, are in progress. 



Peach brown-rot and scab. — Experiments were continued in Dela- 

 ware, Michigan, and West Virginia demonstrating the efficacy of self- 

 boiled lime-sulphur solution in the control of the brown-rot and scab 

 of the peach. The mycological investigation of brown-rot and stud- 

 ies of the scab fungus and other peach and apple diseases are in prog- 

 ress at the new field station at Cornelia, Ga. Spraying experiments 

 and demonstrations are being carried on in Delaware, GeorgLa, Michi- 

 gan, Kansas, and Arkansas. 



Bitter-rot and other diseases of the apple. — Spraying demon- 

 strations conducted in 1911 for bitter-rot in Arkansas and for scab in 

 Delaware, Kansas, and Michigan are being continued in the same 

 States in 1912. Work in Kansas caused a revision of the schedule of 



