908 EXPERIMENT STATION RECORD. 



" Since wood ashes contain about one half as much lime in practically the same 

 form, there remains almost no question hut that they will also increase the scab. 

 One ton of air-slacked lime contains in general a little less than 2 tons of wood 

 ashes. 



"It seems probable that the natural acidity or sourness of the soil tends to check 

 the spread of the disease, and the tendency of barnyard manure to increase it may 

 reasonably be attributed to its alkaline action, by which the sourness is overcome. 



" If the fiiriii stock is fed on scabbed beets or potatoes in an uncooked condilion, 

 then barnyard manure may still further increase the disease by carrying to the soil 

 germs which have passed through the digestive organs of the animal undestroyed. 

 If a soil is very acid small quantities of barnyard manure, wood ashes, and air- 

 slacked lime will probably have far less tendency to increase the scab than when 

 large quantities are used. The amounts which it would be safe to apply are doubt- 

 less dependent upon the sourness of the soil. The safest course, until absolutely 

 effective means of disinfecting the seed tubers are found, would be to avoid these 

 substances altogether, provided potatoes are to be grown successively or in frequent 

 rotation upon the same land. Upon such soil lime not only increases the total 

 yield but also the percentage of tubers of large size, so that if only one crop were 

 to be grown the use of lime would prove decidedly beneficial, for the efi'ects from 

 the scab are not serious the first year. When grown under these conditions, the 

 corrosive sublimate treatment has lessened decidedly the amount of scab. It is pos- 

 sible by the use of this treatment that potatoes may be grown upon limed soil suc- 

 cessively or in frequent rotations without the arising of serious injury from the 

 scab, yet our observations up to the present time make it appear very doubtful if 

 this can be done." 



Experiments conducted with about 50 agricultural plants show that 

 lime favors the growth of most of them, and the developmeut of scab 

 onpota-toes is the only drawback to its general use on acid soils that 

 has so far been observed by the authors. 



Report of the botanist, L. R. Jones {Vermont 8ta. Rpt. 1893, pp. 

 41-69, Jigs. 7). — The author gives detailed reports on experiments in 

 spraying potatoes; time and rate of growth of potato tubers and effect 

 of i)remature death of potato tops on the yield ; relation of time of 

 planting potatoes to diseases; and a spray cart for potatoes. These 

 different articles are in the main reprinted from Bulletin 40 of the 

 station (E. S'. R., 5, p. 988). 



In the experiments in spraying ijotatoes the author reports in detail 

 on the use of Bordeaux mixture, ammoniacal copper carbonate, copper 

 and ammonium carbonate solution, modified eau celeste, sulphosteatite 

 and copper sulphate of various strengths of solution. The author con- 

 siders that Bordeaux mixture is the best fungicide for the prevention 

 of potato diseases. 



A report is given on the loss occaeioued by oat smut in Vermont in 

 1893. Ninety- eight fields were sampled, the total number of heads 

 examined being 39,826, showing that 0.82 per cent was smutted. A com- 

 parison of Vermont-grown seed with that grown in other localities 

 shows less smut from the home-grown seed. 



Black knot of plums and cherries and methods of treatment, 

 E. G. LoDEMAN {New York Cornell Sta. Bui. 81, pp. 635-636, Jigs. 6). — 

 According to the author the black knot of plums and cherries, which 



