DISEASES OF PLANTS. 1053 



entrance of the vascular bundles. If gathered and stored dry during 

 the winter but little change will take place in the tubers, but if stored 

 wet various kinds of rot may attack them, the fungi living as sapro- 

 phytes on the stored reserve. 



The author states that this fungus leads the way for a number of 

 purely saprophytic forms, and the evidence seems to show that the 

 parasite is planted with the tubers. On this account the potato grower 

 must exercise care in the selection of his seed and the preparation of 

 his ground. In a subsequent paper the author intends treating the 

 subject at greater length and expects to show that allowing the young 

 shoots to lie in contact with the soil or manures is a possible means for 

 spreading the disease. The same applies to wet soils and situations, 

 and the disease is said to be particularly liable to increase when wet, 

 cold weather follows early growth. 



Diseases of the tomato, P. II. Rolfs (Florida 8ta. Bui. 17, pp. 115- 

 153, pis. 2). — This bulletin treats of some of the more important diseases 

 that have been observed to attack the tomato in Florida. 



The rust, black rot, spot, or black spot, due to Macrosporium solan i, 

 is figured and described. As a preventive remedy thorough spraying 

 with Bordeaux mixture is recommended, at least two applications to be 

 given the plants in the seed bed and the number of sprayings in the 

 field varied with the conditions of the weather. 



The bacterial blight of tomato (Bacillus solanacearum) is briefly 

 described, the principal characters together with the treatment being 

 largely drawn from Bulletin 12 of the Division of Vegetable Physiology 

 and Pathology of this Department (E. S. R., 8, p. 895). 



Experiments are reported in which the effect of fertilizers on this 

 blight was tested, from which it appeared that while healthy, vigorous 

 growing plants seemed to show the effects of the blight less quickly 

 than the small, stunted ones, both ultimately succumbed to the disease. 

 Different forms of potash and nitrogen were tested, but no single form 

 seemed to be superior; bone phosphate was found no better than acid 

 phosphate. A fertilizer which would tend to produce a strong, woody 

 stem would be slightly better than one producing a rapid, succulent 

 growth. The relation of different varieties to this blight was investi- 

 gated and there seems to be some difference in susceptibility. Consid- 

 erable advantage may be obtained in having the plants as widely sep- 

 arated in rows as possible, as this will tend to prevent the rapid spread 

 of the disease. 



A fungus blight of the tomato has been under investigation for about 

 6 years, but the conditions do not yet warrant the classification and 

 identification of the organism present. When the plant is affected by 

 this disease a single leaf may be observed to droop as though from want 

 of moisture. Later it may regain its normal appearance, to resume its 

 wilted condition in a day or so. In severe cases the whole plant may 

 be affected in this way. A plant once affected rarely recovers, and 



