i9io.] 



Tomato and Potato Bacteriosis. 



297 



could only be estimated upon a statement of the main condi- 

 tions obtaining in each case. 



As, however, something of the success of small holdings 

 will depend upon the manner in which the subject of water 

 supply is treated, it may be urged that full consideration 

 should be given in the case of each group to the possibility 

 of providing, with all due regard to economy, a system which 

 will not only justify a business-like dependence upon its 

 efficiency but also admit of future expansion as occasion 

 may require without unnecessary multiplication of its essential 

 parts. 



This disease has been known for some time in the United 

 States, where it has been carefully studied by Dr. Erwin F. 



Smith. The organism concerned is 

 Tomato and Potato called Bacillus solanacearum, E. F. 

 Bacteriosis. Smith. Potatoes, tomatoes, and egg- 



plants are attacked, sometimes on a 

 large scale, in America. In this country it was first observed 

 in 1902 (Jour. Bd. Agric, IX., p. 308) in small quantity on 

 potatoes grown in the North of England and in Scotland. 

 During the present season the same disease has attacked 

 tomatoes to a somewhat serious extent, examples having been 

 received at Kew from two localities, where it is stated to be 

 present in an epidemic condition. 



The symptoms indicating the presence of the disease on 

 tomatoes are well marked. Infection usually takes place at or 

 near the tip of the stem, the disease gradually working down- 

 wards, passing into the leaves and flowering shoots as it does 

 so, until the root is reached. Shortly after infection the 

 uppermost leaves commence to wilt, curl and turn yellow. 

 The leaves become marked with many rather small, scattered, 

 blackish-brown blotches, and long dark-brown streaks appear 

 on the surface of the stem. If the stem be cut across, the 

 vascular bundles or woody portion present a brown appear- 

 ance, and on microscopic examination the vessels are found 

 to be teeming with bacteria. The fruit also becomes more or 

 less covered with dark-coloured blotches, which at first are 

 quite superficial, but gradually increase in size and assume 

 a watery consistence, finally collapsing and forming irregular 

 pits on the surface of the fruit. After the spots on the fruit, 

 which are at first crowded with bacteria, have collapsed, 

 k \: ' . - Y 



