860 EXPERIMENT STATION RECORD. 



cells, which become more or less transformed. This disease in the 

 orchard examined was exceedingly abnndaut, and the small tumors 

 were found on 30 out of 50 trees and in a few hours as many as .100 

 affected branches were cut out. The peach tuberculosis has frequently 

 been confused with the bacterial gummosis of pomaceous fruits, but 

 the author maintains that they are very distinct. It is said that by 

 pruning the course of this disease may be arrested, although no experi- 

 ments are reported where its efficiency has been tested. 



Fungus diseases, J. Craig (Canada Expt. Farms Rpt.l897,2>P- 110- 

 120). — Notes are given of a number of the more common parasitic dis- 

 eases of cultivated plants, and experiments are reported on the effect 

 of shading on the production of gooseberry mildew. The plants were 

 shaded by planting hills of corn on the south, east, and west sides of 

 the gooseberry plants. The results obtained seem to indicate that the 

 shading reduced the amount of gooseberry mildew, and this experi- 

 ment is to be repeated on a more extensive scale. 



Attention is called to the attack of Heterosporium gracile on species 

 of cultivated iris, and applications of Bordeaux mixture are recom- 

 mended as a preventive treatment. 



A dry rot of apples which is said to be caused by a fungus closely 

 resembling Penicillium glancum is briefly described. 



A peach disease which has been observed for several years is 

 described, the characteristics of it being abnormally thickened annual 

 shoots; a marked increase in the buds; tufted broom-like growths 

 involving a single twig or branch, or sometimes even the entire top of 

 the tree, the color of the foliage being somewhat lighter green than 

 normal and the leaves much narrower and contorted. The symptoms 

 of this disease are somewhat like those of peach rosette, and specimens 

 submitted to the Division of Vegetable Physiology and Pathology of 

 this Department were identified as resembling rosette, but no positive 

 opinion was given. On account of the serious nature of this disease 

 the author recommends the cutting and burning of all affected trees. 



A serious grape disease has been under observation for several years. 

 The affected vine may be recognized by the leaves, which become light 

 yellow in color; the canes are shortened and the tendrils often abor- 

 tive. The root system is very imperfect. Microscopical examination 

 of affected plants did not reveal any fungus, bacteria, or insect that 

 could be positively identified as the cause of this disease. Assuming 

 that the trouble may be due to a lack of nutrition, a series of experi- 

 ments has been begun with different fertilizers and these will be con- 

 tinued for some time. 



Experiments for the control of potato scab were conducted in which 

 2 varieties of potatoes were treated with various fungicides. The ones 

 used were corrosive sublimate, kainit, nitrate of soda, potassium sul 

 phid, sulphur, formalin, and lysol. The results obtaiued by these 

 experiments showed that there was a marked difference in the 2 varie- 

 ties in their susceptibility to the potato scab, one variety being affected 



