478 THE MONTHLY BULLETIN. 



THE MONTHLY BULLETIN 



CALIFORNIA STATE COMMISSION OF HORTICULTURE 



DEVOTED TO HORTICULTURE IN ITS BROADEST SENSE, WITH SPECIAL 



REFERENCE TO PLANT DISEASES, INSECT PESTS, AND 



THEIR CONTROL. 



Sent free to all citizens of the State of California. Offered in exchange for bulletins 

 of the Federal Government and experiment stations, entomological and mycological 

 journals, agricultural and horticultural papers, botanical and other publications of a 

 similar nature. 



A. J. CooKj State Commissioner of Horticulture Censor 



E. J. VosLER, Secretary State Commission of Horticulture Editor 



ASSOCIATE EDITORS. 



Geo. p. Weldon Chief Deputy Commissioner 



Harry S. Smith Superintendent State Insectary 



Frederick Maskew Chief Deputy Quarantine Officer 



Entered as second class matter December 29, 1911, at the post office at Sacramento, 

 California, under the act of July 16, 1894. 



A New Grape Disease. — Bulletin No. 289, Agricultural Experiment 

 Station, Geneva, New York, will greatly interest the many grape growers 

 of California. It describes quite fully a new disease, "the dead arm 

 disease," which is supposed to be indigenous to the United States. It 

 is fungoid in nature, very serious in its effects and seems to be prev- 

 alent everywhere in the eastern grape growing regions. Its name in- 

 dicates the characteristics, and its presence may be determined by the 

 leaves turning yellow, crimpling up and finally the long lateral canes 

 dying. It does not seem to descend to the roots, or if so, rarely, as 

 sprouts below the ground seem to be free unless infected by new spores. 

 Infected canes not pruned are supposed to be the means whereby the 

 fungus gives rise to new infestations. The disease frequently creeps 

 down to the main stems, and the vines often die in the second or third 

 year. We already have our share of vine diseases in California, and it 

 is a question whether we are warranted in bringing grapes from the 

 East, as there seems no need of doing this, and of course there would be 

 danger of introducing this new and serious malady. — A. J. C. 



Pov^rdery Mildew of Apple. — Bulletin No. 120 has been published 

 by the Bureau of Plant Industry, on Apple Powdery Mildew, and its 

 Control in the Pajaro Valley. This bulletin was written by W. S. Bal- 

 lard, pathologist, fruit disease investigations for the Bureau, and W. H. 

 Volck, county horticultural commissioner of Santa Cruz County. The 

 results of cooperative experiments are treated upon very fully in this 

 bulletin. The authors state that this disease may be caused by either 

 of two similar fungous organisms, namely, Podosphcsra leucotricha and 

 Podosphcera oryacantlice, the former species being the one that is doing 

 the damage in the Pajaro Valley, the orchards of this valley suffering 

 more from mildew caused by this fungus than do those of any other 

 large apple growing district of the United States. It is further stated 



