EXPEKIMENT STATION REPORT. 545 



Diieases of Tomatoes. 



From the above report? of crop correspondents concerning the con- 

 dition of the tomato industry in the State during the past season it 

 is evident that there has been much trouble with one of its leading 

 truck crops. In fact, for some years past the growing of tomatoes 

 has been attended with much anxiety, due to several causes, but chief 

 among them are the various fungous enemies. 



The subject of tomato growing, particularly that of its diseases, 

 has been considered by this department, as a reference to the past 

 reports will show, and it may be well to make a summary of the 

 points that have been gained. 



Tomoto Bacteriosis. — One of the most diflficult diseases of the 

 tomato for the trucker to contend with is the Bacteriosis, due to a 

 microbe (Bacillus Solanacearum Sm.), which is often first recognized 

 by a sudden wilting of the foliage, that soon changes to a yellowish- 

 green and then to brown. Dr. E. F. Smith* has made a special study 

 of this disease, and succeeded in inoculating the Jamestown weed, 

 black nightshade, ground cherry and petunias, all of which belong to 

 the tomato family of -plants, with this wilt disease. 



The disease is spread by moans of the microscopic garms, and any- 

 thing that opens up a passageway from the atmosphere to the tissue 

 within will tend to develop the disease. Dr. Smith has been able to 

 transmit the microbes from one plant to another by means of Colorado 

 potato beetles, and determined tlie time of incubation to ha from seven 

 to nine days. Other insects, most likely, are active agents in the 

 spread of this disease. 



Concerning preventive measures, it is evident tliat tlie injuries 

 from insects should be reduced to a minimum by using mixtures that 

 will destroy these pests, and thereby preserve the skin of the tomato 

 plant intact, thus destroying the carrier of the germs and keeping 

 the natural barrier unbroken. When plants go down with this disease 

 they should be burned, so that they may not remain as sources of 

 the infection. .Vs a further precaution, tomato growing should not 

 be attempted continually upon any soil, and emphatically so when 

 this disease is in evidence. . Lastly, procure plants that are not likely 

 to have been exposed to the Bacteriosis before being set in the field. 



*A Bacterial Disease of Tomato, Eggplant and Irish Potato. Bulletin 12, Division 

 of Vegetable Pathology and Physiology, U. S. Department of •\gricujture 1896. 



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