138 EXPERIMENT STATION RECORD. 



Notes are given upon potato scab, wliicb is commonly caused by 

 Oospora scabies, and tbe corrosive sublimate treatment is recommended. 

 The i^nblications of several stations are drawn upon for information 

 relative to tlie effect of acid and alkaline conditions of the soil upon 

 the disease. Formulas for the fungicides used and the results of some 

 experiments for the repression of the disease are given. 



!N"otes are included on the potato beetle and flea beetles, with direc- 

 tions for their destruction. Arsenites have proved most efficient for 

 the potato beetle, while Bordeaux mixture seems most promising for 

 protection against flea beetles. 



A report is given of a comparative trial of different forms of spray- 

 ing apijaratus for applying Bordeaux mixture to potato plants. It was 

 found that power sprayers were generally the best, those depending 

 upon gravity for the distribution of the fungicide not proving wholly 

 satisfactory. For the application of dry insecticides the powder guns 

 tested were very satisfactory. 



Potato blights and fungicides, L. R. Jones ( Vermont Sta. Bui. 49, 

 pp. 81-99, Jigs. 4). — Notes are given on selection of seed tubers as a means 

 for the prevention of late blight, tests of different forms of Bordeaux 

 mixture, and various forms of potato blight. 



In 1895 the late blight was about 2 weeks late in attacking pota- 

 toes. This was due, the author thinks, to the unusual freedom from rot 

 of the crop of 1894, the one su])plying the seed. It is thought that by 

 selecting for seed only tubers from lields of early j)otatoes which have 

 escaped late blight, attacks of late blight would be almost wholly pre- 

 vented. Comparative trials of various kinds of Bordeaux mixture and 

 of Bordeaux x)owders show that fresh liquid preparations of standard 

 strength gave the best results. Directions are given for the best way 

 to make Bordeaux mixture as shown by the author's experiments. 



By the term blight is generally meant any injury resulting in the 

 premature dying of foliage of the i)otato. The author recognizes at 

 least 4 forms of blight, the successful treatment of which requires that 

 the cause be definitely known. The late blight, or mildew, is caused by 

 Fhytophtliora infestans, and may be prevented by planting sound seed 

 and spraying the plants with 2 or 3 applications of Bordeaux mix- 

 ture. The early blight, or leaf-spot disease, is due to attacks of Macro- 

 sporium solani upon plants that are more or less weakened from various 

 causes. The measures suggested for preventing this form of blight are 

 to increase the vigor of the plant by selection of varieties, better culti- 

 vation and fertilization of the soil, later planting, and spraying the 

 plants with Bordeaux mixture. Arsenical jioisoning by the improper 

 use of Paris green produces a condition resembling the blight due to 

 Macro siiorium, and may be avoided by using smaller amounts of Paris 

 green, or adding lime to the water if it is applied in this form. When 

 applied dry, it may be diluted with plaster. Tip burn, which is caused 

 by dry, hot weather, aided by other conditions unfavorable to the plant, 



