8 MASS. EXPERIMENT STATION BULLETIN 393 



a study of strains or physiologic forms of the fungus was not undertaken. It is 

 evident, however, that in addition to pathological reactions manifested by 

 Lycopersicon, cutaneous responses of persons allergic to the fungus should also 

 be extremely useful in differentiating physiologic forms. 



SUMMARY 



Bay State, a new tomato for greenhouse forcing, is described and illustrated. 

 It was developed for resistance to Cladosporium leaf mold from crosses of Lyco- 

 persicon pimpinellifolium (Jusl.) Mill, and L. esculentum Mill., respectively highly 

 resistant and highly susceptible. 



The new tomato was released for commercial trial in 1939, and approximately 

 one-fourth of the greenhouse tomato area in Massachusetts was planted to this 

 variety in the fall cropping season cf 194L 



In the fall cropping season of 1940, however, the Bay State tomato growing in 

 a greenhoLse in Swansea , Bristol County, experienced a severe attack of leaf mrld, 

 caused by a new physiologic form of Cladosporium. In the fall of 1941 other 

 instances of the susceptibility of Bay State to the new physiologic form of the 

 fungus were observed. The Globelle and Vetomold varieties of tomato, likewise 

 developed for resistance to Cladosporium fulvnm Cke. and derived from L. pim- 

 pinellifolium, have shared the same experience in Massachusetts and elsewhere. 



The new physiologic form of the fungus is infectious to L. pimpinellifolium , 

 causing yellowish infection flecks and ultimately necrosis. On the lower leaf 

 surface of the necrotic areas and under moist atmospheric conditions, the fungus 

 grows and sporulates rather freely. This form of the fungus is considered to be 

 less virulent on the Bay State tomato than the normal devastating physiologic 

 form on Waltham Forcing; and with some degree of proper greenhouse manage- 

 ment should ja'eld more readily to control. 



LITERATURE CITED 



1. Ale.xander, L. J. Leaf mold resistance in the tomato. Ohio Agr. Expt. Sta. 



Bui. 539. 1934. 

 2 A new tomato variety resistant to leaf mold. Phvtopath. 28:1. 



1938. 



3 A new strain of the tomato leaf mold fungus Cladosporium 



fulvum. Ph3'topath. 30:1. 1940. 



4. Bailey, D. L., and Langford, A. N. One hundred percent leaf mold infec- 

 tion reported on Vetomold. Canad. Plant Dis. Survey, Ann. Rpt. 20 (1940): 

 57. 1941. 



5. Bond, T. E. T. Infection experiments with Cladosporium fulvum Cke. and 

 related species. Ann. Appl. Biol. 25:277-507. 1938. 



6. Cuba, E. F. Control of greenhouse vegetable diseases. Mass. Agr. E.xpt. 

 Sta. Bui. 305 (Ann. Rpt. 1933. ):18. 1934. 



7 A new red forcing tomato resistant to Cladosporium leaf mold- 



[Phytopath. 29:9. 1939. 



[S Control of tomato leaf mold in greenhouses. Mass. Agr. Expt- 



Sta. Bui. 361. 1939. 

 9. Langford, A. N. The parasitism of Cladosporium fulvum Cke. and the 

 genetics of resistance to it. Canad. Jour. Res. (Sect. C) 15:108-128. 1937. 

 10. Sengbusch, R. V., and Loschakowa-Hasenbusch, N. Immunitatsziich- 

 tung bei Tomaten. Ziichter 4:257-264. 1932. 



