No. 2, December, 1921] PATHOLOGY 109 



during the summer. All 3 substances produced the desired effect, but the 2 liquids were su- 

 perior to the dust. No difference was noticeable between copper sulphate and "perozid" 

 spray. — //. T. Giissow. 



704, Blodgett, F. M., and KarlFernow. Testing seed potatoes for mosaic and leaf-roll. 

 [Abstract.] Phytopathology 11: 58-59. 1921. 



705. Erwin, a. T. Control of downy mildew of lettuce. Proc. Amer. Soc. Hort. Sci. 

 17: 161-16S. 1920 [1921]. — Twenty-seven varieties of lettuce representing the looseleaf cos 

 and head types were found to be susceptible to lettuce mildew, Bremia laciucae. Attack was 

 found to be most severe in the seedling stage, especially during the "unfolding of the cotyle- 

 dons and the expanding of the first true leaf. If the plants can be kept free from mildew until 

 they are half grown, the disease is of comparatively little importance." Several species of 

 wild lettuce under observation were readily infected by cultures obtained from cultivated 

 lettuce, and conversely the mildew of the wild lettuce grew readily on the cultivated varieties, 

 showing the necessity of destroying wild lettuce in the vicinity of the greenhouses. Drenching 

 the soil with formaldehyde solution (7 pints of formaldehyde to 100 gallons of water), applied 

 at the rate of 1 gallon per square foot, did not control the disease. Bordeaux mixture of 2: 2: 50 

 strength sprayed on the seedlings just before the true leaves appear and a 2nd spraying 1 or 

 2 days before transplanting will readily control lettuce mildew. — H. A. Jones. 



70G. Fromme, F. D,, and S. A, Winqard. Treatment of tobacco seed and suggested 

 program for control of wildfire and angular-spot. [Abstract.] Phytopathology 11: 48-49. 

 1921. 



707. Keitt, G. W. Second progress report on apple scab and its control in Wisconsin. 

 [Abstract.] Phytopathology 11 : 43-44. 1921. 



708. KocK, GusTAV. Die wirtschaftliche Bedeutung der Kartoffelkrautfaule und die 

 Moglichkeiten der Bekampfung dieser Krankheit. [The agricultural importance of potato late 

 blight and the possibility of controlling this disease.] Oesterreich. Zeitschr. Kartoffelbau 

 P: 20; P: 23. 1921. — A popular description is presented of late blight disease of potatoes, 

 including control measures. A copper chloride-lime, proprietary preparation known as 

 "Bosna-Pasta," is recommended as being equal to 1 per cent Bordeaux and as eliminating the 

 necessity of filtering or adjusting the reaction of the mixture. — F. Weiss. 



709. Kroxtt, Webster S. Treatment of celery seed for the control of Septoria blight. 

 Jour. Agric. Res. 21 : 369-372. 1921. — Mycelium and spores of Septoria apii on or in the seeds 

 of celery [Apium graveolens] are either dead or very low in vitality at the end of 2 years and 

 both are dead at the end of 3 years, whereas the seeds are viable for 4 years or more. — The 

 thermal death point (30 minutes) of the spores in tubes is between 38° and 40°C., that of my- 

 celium in tubes about 45°; and that of seeds, 1 or 2 years old, is between 50° and 55°. Pre- 

 ferred temperature for treatment is 48 or 49°C. for 30 minutes. — D. Reddick. 



710. Martin, William H. Inoculated vs. uninoculated sulfur for the control of common 

 scab of potato. [Abstract.] Phytopathology 11: 58. 1921. 



711. Melhus, I. E. Cooperative potato seed treatment experiments (Committee Report). 

 [Abstract.] Phytopathology 11: 59-60. 1921. 



712. Melhus, I. E., J. C. GiLMA>f,AND J. B. Kendrick. The fungicidal action of formal- 

 dehyde. Iowa Agric. Exp. Sta. Res. Bull. 59, 355-397, fig. 6. 1920.— The studies reported 

 in this bulletin deal with the toxic action of formaldehyde and other surface disinfectants 

 as manifested in potato seed treatment. The organisms used were Actinomyces scabies and 

 Rhizoclonia solani. Surface disinfection with formaldehyde for the control of scab was more 

 complete at 20°C. than at lower temperatures. Formaldehyde at 4S-50°C. for short periods 

 of time was as toxic as mercuric chloride and formaldehyde of the standard formulae. Cover- 



