548 EXPERIMENT STATION RECORD. 



in general that in the case of all of the 3 enzyms studied — oxygenase, peroxidase, 

 and tyrosinase — the activity was greater in diseased than in healthy tubers. 



Protection of tubers from potato disease by spraying with Bordeaux mix- 

 ture, H. M. QuANjEE {Tijdschr. Plantenziekten, 17 (1911), No. 1-2, pp. 35- 

 47). — The author answers complaints from some sections to the effect that Bor- 

 deaux mixture was found to be ineffective or detrimental as regards the tubers, 

 by giving observations and experiments of himself and several potato raisers, 

 dealers, and investigators. He concludes that it is possible not only to protect 

 the foliage from the disease, but also to keep it almost entirely from the tubers, 

 and thereby to increase the value of the crop, by spraying with Bordeaux mix- 

 ture in sufiicient quantity before the warm wet weather releases the swarm 

 spores and carries them down to infect the tubers. 



Heterosporium variabile, its relation to Spinacia oleracea and environ- 

 mental factors, II. S. Rked and J. S. Cooley (Centbl. Bakt. [etc.], 2. AM., 32 

 (1911), No. 1-2, pp. ^OSS, figs. 9). — Investigations were made on the disease 

 called rust, affecting the nearly mature plants of the variety of spinach known 

 as the Norfolk Savoy gi-own in the open fields about Hampton Roads, Va., dur- 

 ing the winter months. This disease was found to be due to a fungus, H. varir 

 al)ile, and in-evious accounts of it have been noted elsewhere (E. S. R., 25, p. 

 846). The report thereon may be summarized as follows: 



H. variaMJe is not a strong parasite, as is evidenced by its attacking only such 

 plants as have been weakened or injured by other agencies, for example, leaf 

 cutters, other parasites (among which may be named Peronospora effusa, 

 Maarosporium sp.. and Phyllosticta chenojwdii?) , acids, vapors, cold, unfavor- 

 able soil conditions, etc. Once inside the plant it ranges freely from cell to 

 cell. The fungus seems to exert a positive toxic influence upon the cells of the 

 plant, probably because of one or more of several enzyms found in the cultures. 



Close study justified the name of the fungus by confirming its variability in 

 form and habit. When first isolated it grows poorly as a saprophyte, but in 

 the course of time, during which it undergoes changes of form and habit, it 

 grows luxuriantly as a saprophyte. One of the most striking illustrations in 

 the development of the fungus is the process by which the spores arise by 

 budding either from hyphae or from one another. The budding process appears 

 to be uninfluenced by the acidity of the solution, by the presence or absence of 

 oxygen, or by the dilution of the medium, and seems rather to be due to the 

 conditions imposed by the saprophytic mode of life in artificial cultures. 



Blight of the sugar beet and protection therefrom, D. Hegyi (ZtscJir. 

 Pflanzenkrank., 21 {1911), No. 5, pp. 269-276). — This most destructive disease, 

 it is stated, appears to be due to the presence of one or the other of 2 fungi, 

 Phonia hetw and PytMum de Ixinjanum, or of certain soil bacteria. It may ap- 

 pear on plants from infected seed, or in case of infected soil may attack plants 

 sprouted from perfectly healthy seed. The author found that in case of seeds, 

 either artificially or naturally dried but containing only from 10 to 12 per 

 cent of water, the plants on germination were entirely free from blight, and 

 remained so even when the soil contained the bacteria and spores of the fungi. 

 Seeds that contained 16 per cent of moisture, however, germinated more slowly 

 and produced fewer and weaker seedlings, showing 17 per cent or more of 

 blight, which soon spread to all the plants. 



Drying the seed artificially is therefore urged, and strengthening the plants 

 by appropriate fertilization and proper cultivation of the soil is also insisted 

 upon. 



The red rot of sugar cane, C. W. Edgerton {Louisiana Stas. Bui. 133, pp. 

 22, pJs. 4). — Some 2 years ago the author announced the discovery of the red 

 rot of sugar cane due to Colletotrichum falcatum in Louisiana (E. S. R., 23, 



