NOTES AND ABSTRACTS. 



number : (i) the perforated pipe method of steam sterilization ; (2) the inverted 

 pan method, using steam ; (3) the formaldehyde or formalin drench method. 



The perforated pipe method of steaming consists of a set of perforated pipes 

 with crosshead and high-pressure boiler connection. The pipes are buried in 

 the soil and the surface covered with canvas. Steam is now passed into the 

 pipes and so into the soil for about an hour. The temperature of the soil is 

 raised to i8o°-2i2 u F. The size of the buried pipes is i£ inch. 



The inverted pan method was originally used in Florida for nematode-infectcd 

 soils. The apparatus is a galvanized iron pan, 6 inches deep by 6 feet by 10 

 feet, and this is inverted over the soil to be sterilized and steam admitted under 

 pressure. 



The formaldehyde drench method. The appliances used are various, though 

 usually some form of sprinkling can, or a force pump with hose and nozzles, are 

 used. 



The relative cost for treating (say) 3,000 sq. feet is $15.40 by the perforated 

 pipe method ; $12.20 by the inverted pan method ; and $21.00 by the formal^ 

 dehyde drench method. — A. B. 



Sugar Beet, Leaf-spot Disease of. By C. O. Townsend (U.S.A. Dep. Agr., Bur. 

 PI. Ind., Farm. Bull. 618, pp. 1-18, Oct. 1914 ; 10 figs.). — Leaf-spot disease of 

 the sugar beet (Cercospora beiicola) is a widely-distributed fungus in the States 

 of America. By attacking and destroying the leaves of the growing crop, the 

 plants are unable to mature and are frequently deficient in sugar. The best 

 methods for the control of disease include a carefully-planned and thorough 

 system of crop rotation and a systematic spraying with Bordeaux mixture 

 (4-4-50) on the first indication of the fungus. A constant and unifoim supply 

 of moisture is also of value in reducing and retarding the developmen of 

 " leaf -spot." — A. B. 



Sulphur in Plant Nutrition. By H. L. Russell (U.S.A. Exp. Stn., Wiscon- 

 sin, Rep. 191 3 ; pp. 18 and 19). — In greenhouse trials on soil containing "04 

 per cent, of sulphur trioxide it was found that such high protein and sulphur 

 plants as rape, radishes, turnips, and clover, responded in a marked degree to the 

 application of a sulphate fertilizer, clover yielding 35 per cent, increase in dry 

 matter, where gypsum had been added to a so-called complete fertilizer, and 

 containing an abundance of sulphates in the sap, whereas on a soil where no 

 sulphate had been applied the plants contained absolutely no circulating sul- 

 phates, showing that the growth of the plants was being limited because all the 

 sulphates obtained by the plants from the soil had been built up into organic 

 plant compounds. — A. P. 



Tobacco, Black Rot, Shed Burn, and Stem Rot of. By James Johnson (U.S.A. 

 Agr. Exp. Stn., Wisconsin, Research Bull. 32, June 1914, pp. 63-84; 7figs.). — This 

 paper describes various experiments to determine the causal organisms of the 

 above diseases of tobacco. 



1 . Black Rot is a disease of the tobacco leaf and occurs during the fermentation 

 process. The rot is due to the development of the fungus Sterigmatocystis nigra 

 on the leaves, causing them to blacken and decay. The disease is primarily 

 due to excessive moisture and a temperature of 30 0 to 40 0 C. following infection 

 by the fungus. Thus the control of the black rot disease must depend largely 

 on the regulation of the percentage of moisture in the leaf and the temperature 

 of fermentation. 



2. Shed Burn and Stem Rot of tobacco may be due to one or more species 

 of saprophytic fungi. Fusarium is most commonly the cause of these diseases 

 in Wisconsin. The difference between the two diseases is chiefly one of location. 

 If the fungus attacks the midrib, the disease is called stem rot ; if the leaf tissue 

 is attacked, the disease is called shed burn. 



To control these diseases, the regulation of the temperature and moisture 

 in the curing shed is of supreme importance. — A. B. 



Tobacco, "Calico** of, Chlorosis of Plants with Special Reference to. (U.S.A. 

 Agr. Exp. Stn., Conn., Report of Stn. Botanist, G. P. Clinton, Sc.D., 1914, 

 pt. vi., pp. 357-448 ; 8 plates.) — " Calico " disease of Tobacco is primarily 

 a disease of the chlorophyll of the plant. Thus the normal nutrition of the 

 plant suffers, and the attacked plants present a stunted appearance and 

 bear mottled yellow and green leaves, more or less wrinkled. The disease is 

 infectious and to some extent contagious, and takes from ten to fourteen days 

 to incubate. " Rust " is frequently associated with this disease, usually on the 

 fully-grown leaves» 



