530 Report of the Mycologist of the 



varieties which have a tender skin and show a tendency to crack 

 near the blossom end are more Hkelj to be attacked by " black rot " 

 and also by a white mould, Fusarixim. 



Spraying tomatoes has not been practiced to any considerable 

 extent, although it is likely that it can be done witja profit. Howell^ 

 in South Carolina and E.olfs=^ in Florida report excellent results 

 from the use of Bordeaux mixture against " black rot." Howell 

 spiayed three times with Bordeaux mixture at intervals of two 

 weeks, beginning when the first fruits were three fourths of an inch 

 in diameter. On the sprayed plants only 4 per cent, of the fruit 

 rotted, while unsprayed plants produced 60 per cent, of rotten 

 fruit. Rolfs recommends that the first treatment be made when 

 the flower buds begin to form. 



It is not worth while to record in detail our own experiments 

 because " black rot " was almost wholly absent from the field where 

 most of the experiments were conducted. The previous year 

 tomatoes on this field suffered severely from " black rot " but curi- 

 ously enough the same variety on the same ground the past season 

 showed only a trace of the disease. These were medium late 

 tomatoes. Very late tomatoes of the variety Stone in another field 

 showed considerable rot. It appears that " black rot " thrives best 

 in dry weather, July and August 1894 were dry and " black rot " 

 was abundant. In 1895, July and August were wet, July very wet, 

 and no " black rot " was to be found on the same field. September 

 and October 1895 were dry and the late tomatoes ripening during 

 these months rotted considerably. Dr. Halsted's observation* that, 

 " the more completely the fruit of a plant was sheltered by the 

 foliage the smaller was the percentage of rot," points in the same 

 direction. This i* an exception to the general rule that moisture 

 favors the development of fungi. 



The very late tomatoes, sprayed three times, August 2, 15 and 27, 

 had first fruits two-thirds grown at the latter date. They suffered 

 much less from rot than did the unsprayed. In all cases spraying 

 was discontinued when the fruit began to ripen. Up to this time 

 sprayed plants were much better in foliage than unsprayed, but 

 later the Cylindrosporium killed both sprayed and unsprayed. It 

 is evident that the Cylindrosporium disease can not be controlled 



2 U. S. Dep't of Agr., Sec. of Veg. Pathology, Bull, No. 11, 1890, pp. 61-65. 



3 Florida Exp. Sta. Bull. No. 21, 1893. 



4 New Jersey Agr'l Exp. Sta. Bull. No. 108, p, 19. 



