No. 1, May, 1921] PATHOLOGY 79 



ERADICATION AND CONTROL MEASURES 



552. Anonymous. Certification of stocks of varieties of potato which are immune from 

 wart disease. Scottish Jour. Agric. 3 : 52-66. 1 -pi. 1920. — The Board of Agriculture of 

 Scotland has undertaken the enforcement of regulations prohibiting the planting of sus- 

 ceptible varieties in infected lands and is inspecting fields of immune varieties for certifica- 

 tion as to varietal purity. No crop is certified which contains more than 0.5 per cent of 

 rogues. Over 17,000 acres of approved immune varieties were certified in 1919. Distinguish- 

 ing characters of immune varieties and common rogues are given. — H. V. Harlan. 



553. Anonymous. Beispiele erfolgreicher Beizung. [Examples of successful seed treat- 

 ment.] Mitteil. Deutsch. Landw. Ges. 35: 616. 1920. — A brief note giving the results from 

 treating rye with "Uspulin" and with "Fusariol" against Fusarium as reported by Dr. Steher, 

 Liibeck, in Zeitschr. Landw. Kammer Braunschweig. Based on a check plot treated with 

 "Uspulin," a loss of 44,800 marks occurred on the untreated portion of the field. Fusariol 

 treatment also resulted in large increases of grain and straw. — A. J. Pieters. 



554. Barker, B. T. P., C. T. Gimingham, and S. P. Wiltshire. Sulfur as a fungicide, 

 Ann. Rept. Agric. and Hort. Res. Sta. Univ. Bristol 1919: 57-75. 1919. — Polysulfides possess 

 fungicidal properties and act as contact fungicides. Tests of the decomposition products 

 of polysulfides show that elemental sulfur is the essential fungicidal ingredient of the decom- 

 posed solutions. Spores of parasitic fungi are inhibited in germination by the presence of 

 sulfur in hanging drops in the following order: Sclerotinia fructigena and Phragmidium sub' 

 corticium, 100 per cent inhibition; Cladosporium fulvum, Fusicladium dendriticum, F. pyrinum, 

 50 per cent; Nectria ditissima, Botrytis cinerea, and Verticillium sp. no inhibition. — The 

 acid or alkaline reaction of secretion from germinating spores has no correlation with 

 susceptibility to sulfur, although precipitated sulfur seems to be brought into solution by 

 the secretions of various fungi and apparently to some extent by agar when used as a medium 

 for germination. — D. Reddick. 



555. Cadoret, a. Les sulphatages apres le 15 juillet. [The sulphates after July 15.) 

 Prog. Agric. et Vitic. 70: 9-10. 1918.— From investigations conducted since 1877, it is quite 

 definite that the critical period for infection of Plasmopara on the grape {Vitis vinifera) 

 is from July 10 to July 15. During this period the vines should be well covered. If the 

 weather continues wet after July 15, a copper spray should be applied every 8 to 12 days. In 

 dry seasons a monthly application is sufficient. In sections where black rot (Guignardia) is 

 epidemic, as was the case in 1918, the entire period is longer and it may be necessary to 

 employ 1 per cent Bordeaux mixture from June 10 to harvest-time. — H. B. Smith. 



556. Coons, G. H. Experiments on the control of stinking smut of wheat. [Abstract.] 

 Phytopath. 10:54. 1920. 



557. Gimingham, C. T., and G. T. Spinks. Soil sterilization. Ann. Rept. Agric. and 

 Hort. Res. Sta. Univ. Bristol 1919:37-42. 1919.— Soil infested with Chrysophlyctis endo- 

 biotica, the cause of potato wart, was placed in small pots and the following substances incor- 

 porated with it in the amounts indicated: Bleaching powder 1 gram, creosote 0.5 gram, 

 chloro-picrin 0.3 gram, formalin 1 cc, powdered chalk 1.5 gr. (to neutrality) and 7.5 gr., "cy- 

 m^ne" 0.25 gr. Steam-sterilized soil was used as a control. One week later a tuber was 

 planted in each pot. At the same time other pots of the soil were planted and were mois- 

 tened twice each week with the following solutions: Copper sulfate 2 per cent, sulfur dioxid 0.1 

 saturated solution, formalin 1 per cent, bleaching powder 1 per cent. Aside from steam ster- 

 ilization the only agents which reduced the amount of disease to any appreciable extent were 

 copper sulfate, excess of chalk, and perhaps creosote. — Experiments in progress with disinfect- 

 ants for the control of Rhizoctonia on carrots and spinach were discontinued because of the 

 disappearance of the disease. Bleaching powder at the rate of 2 ounces per sq. yd. can be 

 used safely for carrots. When 8 ounces are used severe injury results. — D. Reddick. 



