SCIENCE 



NEW YORK, FEBRUARY 26, 1892. 



EECENT WORK ON PLA.NT DISEASES BY THE DE- 

 PARTMENT OF AGRICULTURE. 



Farmers' Bulletin No. 5, on "Treatment of Smuts of 

 Oats and Wheat,'' is in press and will shortly be issued by 

 the Department of Agriculture. It has been written by W. 

 T. Swingle, a special agent of the Division of Vegetable 

 Pathology, who has studied the subject for three or four 

 years past. After describing the loose smut of oats and the 

 stinking smuts of wheat, there is given a statement of the loss 

 resulting from the diseases. That from the former is esti- 

 mated at from 5 to 10 per cent of the crop, but from the 

 latter as much as 40 to 50 per cent. The author calculates 

 that if the oats had been treated as now recommended, there 

 would have been saved to the country between 1880 and 1890 

 over $162,000,000. 



The treatment, however, now used to prevent smut was 

 only discovered in 1887, and it is known as the Jensen hot- 

 water treatment. The process given is to immerse the seed 

 to be treated, placed previously in a wire-netted receptacle 

 or some other perforated vessel so that the water percolates 

 freely, in a kettle of water at a temperature of 110° F., until 

 all the grains are thoroughly wetted. Then plunge them 

 into a second vessel, with the water heated to 132|^°, for fif- 

 teen minutes, dipping up and down and twirling around so 

 that the hot water comes into contact with all the grains. 

 They are then taken out and dried thoroughly if not sown 

 immediately, but only partially dried if the grain is not to be 

 kept. The treatment for wheat is similar, but the water 

 should be heated to a temperature of 1432-°, and the seed im- 

 mersed only five minutes. 



Potassium sulphide, in the proportions of 1 pound to 24 

 gallons of water, in which the oats are soaked for 24 hours, 

 is also recommended. If made of double strength, an im- 

 mersion of 12 hours will be sufficient. For wheat a solution 

 of 1 pound of copper sulphate to 24 gallons of water, soaking 

 12 hours, and then leaving for 5 or 10 minutes in lime-water 

 made by slaking 1 pound of lime in 10 gallons of water, is 

 considered beneficial in preventing stinking smut of wheat. 



This bulletin is directly in the line of work now being ac- 

 tively pursued by the Department of Agriculture, and es- 

 pecially by the Division of Vegetable Pathology. It is the 

 business of this division to investigate the diseases of plants 

 due to fungi, and the work of the past year has been of such 

 a practical character, that in the treatment of one disease 

 alone, blackrot of the grape, it is calculated to have saved 

 grape-growers between $75,000 and $100,000, or about four 

 times the total amount of the annual appropriation for the 

 whole division. When this is remembered, and it is known 

 that many other diseases, such as pear leaf-bright, apple 

 scab, potato rot and blight, powdery mildew of the grape 

 and apple, celery blight, etc., have been studied, and reme- 

 dies or preventives suggested, the valuable character of the 

 work of the division will be readily seen. 



During 1891 experiments were conducled on an extensive 

 scale in western New York in the treatment of nursery stock, 

 several million trees having been treated with success io 

 preventing the attacks of fungi. The practical character of 

 the work of the division is further shown in its action during 

 the "grape scare" in New York City. Last fall the Board 

 of Health of the city seized a small consignment of grapes 

 that had been sprayed with a solution containing a small 

 amount of copper. This solution, known as Bordeaux 

 mixture, had been found effectual in preventing black-rot, 

 and had been extensively used. When the graves were 

 seized, exaggerated reports of the bad effects resulting from 

 the use of sprayed fruit were telegraphed far and wide, and 

 the grape market was demoralized. As soon as the situation 

 became known in Washington, the chief of the division 

 was sent to New York, and by explaining to the Board of 

 Health the harmlessness of the small amount of copper that 

 properly sprayed grapes received, he allayed the excitement 

 and the market was restored to its previous condition. There 

 is no doubt but that this prompt action saved thousands of 

 dollars to the vineyardists of New York and other States. 

 The amount of copper which the sprayed grapes contain has 

 been shown to be less than that normally present in many of 

 the articles of ordinary diet. 



Besides the bulletin mentioned in the first part of this arti- 

 cle there is ready for the press a report on the virulent vine 

 disease of California, which, appearing near Anaheim about 

 1884 or 1885, has caused widespread destruction of vines in 

 that vicinity. The causes and cure or prevention of this 

 disease are at present unknown, but are being diligently 

 studied with the hope of finding some remedy. There is 

 also in preparation a report upon the work done by the 

 division during the past year, and this will be issued as soort 

 as circumstances permit. Finally, a new number of the 

 Journal of Mycology will be issued soon, which will contain 

 valuable and interesting matter. One article is upon an 

 Almond Disease in California, caused by a fungus attacking 

 the leaves and making them drop prematurely. This article, 

 is illustrated by four plates, and is followed by a statement 

 of how to prevent the attack of the fungus. Another article 

 is on Club-Root, a disease caused by a fungus which attack; 

 the roots of cabbages, turnips, etc. This is also illustrated. 

 Other articles deal with descriptions of new species, or notes 

 upon old ones. An important portion of the number will be 

 the " Index to Literature." This covers the whole subject 

 of diseases of plants, and embraces the literature of the en- 

 tire world. It is the intention to give a brief notice or 

 abstract of the contents of each paper. These notices are 

 arranged under subjects, so that it will be possible for one 

 interested in any special subject to And the articles treating 

 of that subject without wading through the entire index- 

 There will be over three hundred articles indexed in this 

 single index, and an earnest endeavor will be made to have 

 it as complete as possible. 



Joseph F. James, M.Sc. 



Washington, D.C, Feb. 17. 



