194 Proceedings of Indiana Academy of Science 



hosts from the vicinity of the beds. A number of tomato varieties were 

 inoculated with mosaic at Lafayette and all proved susceptible. Pe- 

 culiar, elevated or embossed, brown fruit lesions were observed on 

 badly diseased plants, accompanied by outright blighting of the young 

 shoots. Such severe symptoms are suggestive of certain types of re- 

 sponses on the part of the host in the case of cucumber mosaic. 



Our description of the organism which causes bacterial spot under 

 the name of Bacteriutn exitiosum was antedated by Miss Doidge (10) in 

 Transvaal and as a result the name of the causal organism is Bacteriuvi 

 vesicatoHutn. As a result of our recommendations (21) a considerable 

 amount of the tomato seed used for the canning crop was treated for 

 the control of this disease. The effectiveness of this operation was not 

 carefully checked, but in one region (Jefferson County) where treated 

 seed was used, careful scrutiny of the canning factory sorting belt for 

 several hours on Sept. 8 revealed only three cases of bacterial spot on 

 the fruit. In a Johnson County factory drawing from an acreage planted 

 largely with treated seed, a small amount of bacterial spot was noted 

 on the belt at occasional intervals, but as compared with previous years, 

 the tomatoes were relatively free from the disease. On the other hand, 

 the disease was prevalent as early as July 13 in several fields on plants 

 grown from untreated seed. Leaf, stem, pedicel, and calyx lesions were 

 abundant. Among the 76 fields visited early in the season, bacterial spot 

 was found in ten, and in six of these the plants were known not to 

 have been grown from treated seed. In general the disease made an 

 early appearance this year. Rather severe foliage infection and distor- 

 tion of the young growing parts was noted in three out of 21 fields near 

 Kokomo on July 2. However, southern-grown plants were used in these 

 fields. As a result of inoculation tests, it has been found that insect 

 wounds are not necessary to permit fruit infection and that the charac- 

 teristic fruit lesion is the result of very early infection probably through 

 some natural bi'eak in the epidermis. Although infection has been 

 readily obtained through stink-bug punctures, the resulting lesions are 

 not typical. 



Early blight, caused by Alternaria solani, was found rather severe 

 on the foliage of staked Bonny Be.st tomatoes in Indianapolis market 

 gardens on July 12. Early blight seems to be more prevalent in the 

 canning crop in southern Indiana than in the central part of the state. 

 Late in the season a spotting of the small green fruits i-emaining on 

 the vines was observed in 1920 and again this year, and these lesions 

 are probably attributable to the early blight fungus. These lesions in 

 no way resemble nailhead spot nor bacterial spot. The presence of the 

 elongated, blackened early blight lesions on the stems of young trans- 

 plants and the possible later effect of these lesions upon the plants in 

 the field was noted in our 1919 report (16). A destructive outbreak of 

 a very similar collar rot was reported in a field near Greenfield on 

 July 6. This field was planted with home-grown plants of which about 

 fifteen per cent were weakened and stunted by these stem cankers. The 

 same trouble was also noted to a less extent in one other field in the 

 same locality. Spores of the Alternaria solani type were found on these 

 cankers but there was no foliage infection on the plants. It is be- 



