REPORT OF THE HORTICULTURIST 12J 



SESSIONAL PAPER No. 16 



FUXGOUS DISEASES. 



With the exception of the Black Rot of the grape, fungous diseases were not im- 

 iisiially prevalent this year. Owing doubtless to the almost entire absence of Black 

 Spot of the apple in 1903 in eastern Ontario and the province of Quebec, there was 

 much less spot this year than usual, although some unsprayed orchards were badly 

 affected. In western Ontario, however, the spot was about as bad as usual in un- 

 sprayed orchards, while in orchards well sprayed the fruit was clean. As the plum 

 crop was almost a complete failure, the Ripe Rot was not bad, but grapes suffered to 

 such an extent with Black Rot that growers have become alaiTued, and for this reason 

 some space is devoted to diseases of the grape in the report this year, 



DISEASES OF THE GRAPE IX ONTARIO VINEYARDS IX lOOi, 



Knowing that rot was causing serious damage in a number of vineyards in the 

 Niagara peninsula, I took the opportunity on September 13 and 1-4, of visiting some 

 of them in the hope of learning something that would prove suggestive in fighting 

 the diseases of the grape and of obtaining other information that would be useful to 

 fruit growers regarding the different kinds of rot which were causing loss. On Sep- 

 tember 13, accompanied by Mr, W. H. Bunting, of St. Catharines, Ont., I visited his 

 vineyard and others in the neighbourhood of St. Catharines. Mr. Bunting had sprayed 

 seven times and his fruit was only slightly injured. He had bagged 1,000 bunches 

 when the grapes were tne size of peas in order to find out if infection took place be- 

 fore that time. Most of the bunches thus bagged were perfect, but some had the Black 

 Rot in various stages of development, showing that infection had taken place before 

 the grapes were as large as peas. The Niagara grape was the variety most affected in 

 Mr. Bunting's vineyard. Several vineyards of Concord near Mr. Bunting's were ex- 

 apjined, but Black Rot had not worked to any extent in them. Bro\%Ti Rot was, how- 

 ever, found in one vineyard, but it had not done much injury to the fruit. Another 

 vineyard, probably of about fifteen acres, was visited, consisting principally of Con- 

 cord, Brighton, Niagara and Moore's Early. Of Niagara and Brighton there was 

 scarcely a sound grape anywhere, and none of the bunches of Concord even with mani- 

 pulation could be made fit for market. Moore's Early was not affected. This vine- 

 yard had not been sprayed. 



The infection by the Black Rot as it appeared in the vicinity of St. Catharines 

 was first noticed on the fruit as a round, brownish coloured spot about the size of the 

 head of a pin. This brownish appearance gradually spread over the surface of the 

 berry and by the time one-third of the surface was covered in this way the original 

 brown spot had become paler, showing distinctly the mark of infection. After the 

 whole grape became brown, the tissue gradually shrunk and dried and when thus 

 shrunken the fruit appeared black and prominently and irregularly ridged, the sur- 

 face being covered by small black pustules. On September 14, I visited the vineyaj-ds 

 of Mr. Murray Pettit, Winona, Out., and other vineyards in that vicinity. No Black 

 Rot was noticed at Winona, but Brown Rot was quite abundant, and while it had not 

 caused such damage as the Black Rot, it had done considerable injury. The leaves 

 of the vines affected with Brown Rot had a velvety or downy appearance underneath. 

 The affected friiit first showed a brownish spot or patch one one side and a shrinking of 

 the tissue. This brownish appearance spread all over the grape and the whole grape 

 eventually shrunk into a hard shrivelled mass. Wlien badly affected the vine looses a 

 large amount of foliage. Powdery mildew was also found in these vineyards. 



The Niagara grapes, both in Mr. Pettit's and adjoining vineyards, were affected 

 this year with either a new disease or more probably, as Prof. Selby suggests, a con- 

 dition caused by either Powdery Mildew or Brown Rot affecting the stem to which 

 the grape is att<ichod. This disease causc-d a hardening of the grape and gave it a 

 pale, unhealthy colour. 



