DISEASES OF PLANTS. 81)3 



clieai) iiud efficient remedy for the ineveiitioii of dul. Kx.t. A rcsmiu' 

 of the treatment and results of previons years' wnrk is given, together 

 with the details of experiments conducted in is;)"). 



A summaiy of the author's conclusions shows that kainit did not give 

 favorable results, and that ashes, while they acted as a fertilizer and 

 increased the size of the roots, are not to be reeoinuiended as a renu'dy 

 for club root. The use of gas lime did not reduce the auKJunt of club 

 root, and this fungicide seriously interfered with the growth of the crop. 

 Ijordeaux mixture and animoniacal copper carbonate were tested, but 

 with negative results. Copper sulphate when applied as a imwder at 

 the rate of J ,1'00 lbs. per acre was injurious to the crop and did not 

 diminish the amount of club root, but when the amount was reduced 

 to 000 lbs. per acre the stand was good and the clubbing- somewhat 

 reduced in the second crop. Corrosive sublimate, both in the lirpiid 

 and powder form, was tested, the results showing that the disease was 

 somewhat reduced by its use. The best results were obtained by the 

 use of air-slacked lime, and the experiments indicated that not more 

 thau I.jO bn. nor less than 75 bu. per acre should be used on badly 

 infected laud. The application is most valuable when made in the fall 

 and the lime left on the surface during the winter. 



Experiment!^ with potatoes (pp. 267-283). — The experiments here 

 reported are largely reprinted from Bulletin 112 of the station (E. S. R., 

 7, p. 780). An account is given of the testing of various fnngicides for 

 the prevention of potato scab on Irish potatoes and soil rot of sweet 

 potatoes. The sui)eriority of corrosive sublimate to Bordeaux mixture 

 for soaking seed as a preventive treatment for scab was demonstrated. 

 Field tests where manure was* added to the plats in considerable quan- 

 tity showed an increase in the amount of scab present on the tubers. 

 The use of lime appeared to increase the amount of scab. In one set 

 of exi^eriments the use of kainit seemed to greatly reduce it, as did sul- 

 phate of copjjer, but when the latter fungicide was used the yield was 

 small. Where corrosive sublimate was used as a soil treatment the 

 crop was nearly ruined, the stand of plants being only abont 10 per 

 cent of that of the checks. Sulphur gave the most fa\ orable results on 

 both experimental fields, showing a marked superiority over corrosive 

 sublimate. Simply rolling or dusting the cut seed in sulphur reduced 

 the scab to 5 i)er cent in one lot of 5 experinunits, while the check plats 

 contained as much as 47 per cent of diseased tubers. At the college 

 farm dusting the seed and placing a little sulphur in the o[ien row 

 reduced the ])ercentage of scab from 100 to 5 percent. It was esti- 

 mated that the cost of the sulphur and its application would he abont 

 81 per acre. 



The experiments which were conducted for the treatment of rot of 

 sweet potatoes showed that the largest percentage of disease was on 

 ])lats receiving manure. In this respect they agree with i)revions icsidts 

 given in Bulletin M of the station (E. S. li., 3, p. 703). 'V\\v use of 



