PLANT DISEASES. 



Preventive Measures against Smut. — Dr Julius 

 Kuhn in Mitteilungen des Landwirthschaftliclu'n Institttts 

 de Universitat Halle for March, 1889, advises the follow- 

 ing treatment of grain seed as a preventive of smut : 

 The seed is first soaked for at least twelve hours in a 

 one-half per cent, solution of copper sulphate, which 

 should be used in such a quantity as to cover the lot of 

 seed to the height of the hand. The above mixture of 

 copper sulphate can be made by dissolving one pound of 

 copper sulphate in 22 gallons of water. This solution if 

 then poured off and the seed mixed with milk of lime, as 

 the rate of one pint of the liquid to every pound of the 

 seed to be treated. To prepare the milk of lime, one 

 pound of the best quick-lime is carefully slaked and 

 mixed with ten and one-half gallons of water. The seed 

 should be in contact with the lime water for about five 

 minutes. It is then poured off, and without washing with 

 water the seed is spread thinly upon a floor to dry_ 

 The sowing of the seed should then follow as soon as 

 possible. The seed should be carried to the field in 

 sacks, which have previously been soaked in the one-half 

 per cent, solution of copper sulphate for 16 hours, and 

 then washed in water. The author claims that the ger- 

 minating qualities of the seed are not in the least in- 

 jured by this process. 



Potato Scab. — In Zeitsch dcs Landron-thsc/i, Ccniial 

 Vereins dcr Provinz Stuhseu, January, i88g. Dr. J. Kuhn 

 discusses the prevalent ideas respecting potato scab. 

 The theories that the presence of a large amount of iron 

 in the soil, or the use of manures or street sweepings may 

 favor the scab received no support. The theory that the 

 presence of much lime in the soil aids the growth of 

 scab is denied by the author, who cites cases where po- 

 tatoes have been grown free of scab upon land either 

 naturally rich in lime or made so by the application of 

 marl, and in one case where scabby seed had been used 

 littlescab resulted even upon highly limed land. Walroth 

 believed the cause of the disease to be a parasitic fungus, 

 which he named Erysibe siihterranea, but the author shows 

 that this claim was improbable, inasmuch as the fungus is 

 not always found within the scabby spots. Later, Brung- 

 horst found in the potato a slime fungus, which caused 

 an affection similar to scab, but Kuhn is uncertain 

 whether this is really the true scab, as generally known 

 The whole result of the discussion is to show that none of 

 the theories yet advanced are satisfactory, and the cause 

 of the disease is a question yet open to investigators. 



Sorghum Blight. — Professor W. A. Kellerman in the 

 first annual report of the Kansas Experiment Station 

 describes a hligJit of the sorghum plant, which is char- 

 acterized by reddish blotches on the leaves, leaf sheaths 

 and roots. The disease may in some cases entirely kill 

 the plant, or in mildew cases simply check the growth. 

 The blotches are irregular in shape, though mostly more 

 or less elongated ; but they may widen, so as to in- 

 volve the entire surface. A very faint orange discolora- 

 tion is usually the first indication of the diseased spots, 

 which become deeper, changing to various shades of red. 



and finally to a very dark red. The affection of the leaf 

 extends to the roots, and in some cases the stem at the 

 junction with the roots also becomes discolored and dis- 

 eased. The cause of the malady is a form of bacteria, 

 which Prof. Burrell found in the affected parts and 

 named Baiillus Sorg/ii. The author was able to cul- 

 tivate' these organisms upon sterilized potato and in 

 other nutrient media, material from pure cultures being 

 used to inoculate healthy plants. The result of these 

 inoculations was the production of red streaks like those 

 on the original specimens. The author claims that the 

 disease can be transmitted, to a certain extent, at least, 

 through the agency of soil, infection resulting in 

 most cases by planting seed in soil from a diseased field, 

 while seed planted in soil taken from a source removed 

 from probable contamination gave plants quite or nearly 

 free from the trouble. Burrell claims that the bacillus 

 can retain its vitality through the winter in stalks and 

 stubble remaining in the field, and hence advises the 

 burning of all diseased material, and a proper rotation 

 so as to avoid infection by planting a second crop upon 

 an infected field. 



Diseases of Rose Seeds and Seedlings. — H. 



Drogemuller, in the A'l'nv; Zi-itung, calls attention to the 

 causes which long delayed the production of new varie- 

 ties in Germany, and in the discovery of which he had 

 an important share. The apparent seed of the rose is 

 not a true seed but an achcuL' ; that is, a seed surrounded 

 by a hard shell. This shell has, in the majority of 

 cases, a small hole by which fungus germs, especially 

 those of the common green mould ( PL-niiilliiiin glauciDii), 

 reach the seed itself and destroy it. If the rose seed is 

 not at once placed and kept in air-tight vessels, it will 

 be found on sowing that only about five per cent, germi- 

 nate. Another fungus attacks the roots of the young 

 seedlings. The plants die suddenly without any pre- 

 vious symptoms of disease. Herr Drogemuller found 

 that this root-fungus is a form of the "rust" (P/irag- 

 iiiidiiim siibeorticiim) which attacks the stems and leaves, 

 and that the roots of very many other plants are simi- 

 larly affected by fungi which are merely subterranean 

 forms of other fungi which appear as rusts or mildews 

 upon the leaves. It is not meant by this that the leaf 

 and root fungi are merely varieties of the same fungus, 

 but that each is the actual parent of the other. This 

 phenomenon, called ' ' alternations of generations " is com- 

 mon to many of the lower forms of vegetable life. In 

 the last few years, after this evil had been discovered 

 and remedied (by what means is not stated), a number 

 of fine new German roses have appeared. Among them 

 are Kaiser Wilhelm, Furst Bismarck, Furstin Bismarck, 

 Kaiser Friedrich and Kaiserin Friedrich. The last two 

 are seedlings of Gloire de Dijon, crossed with Countess 

 of Oxford and Perle des Jardins. Kaiserin Friedrich is 

 of a brilliant golden yellow, beautifully shaded with 

 carmine. Perhaps it may be compared to Gloire de 

 Dijon with the colors of Marie van Houtte. It has been 

 pronounced by connoisseurs the finest of the Tea class. 



