156 EXPERIMENT STATION RECORD. [Vol. 41 



Among the symptoms of leaf roll which are often overlooked, the author 

 calls attention to the rolling and rigidity of the lower leaves. The rolling of 

 the upper leaves in some varieties is said to be not particularly conspicuous, 

 while the rolling of the lower leaves seems to be very typical of the disease. 

 Leaf roll may be detected from 5 to 8 weeks after planting, and the author 

 claims that it is safe to assume that if there is no evidence of leaf roll when 

 the plants are 9 weeks old the disease will not develop later. 



In discussing causes, the author states that there is little room for doubt 

 that unfavorable climatic conditions in the previous season or seasons are im- 

 portant factors in the development of leaf roll. 



Two tomato diseases, E. S. Reynolds (Phytopathology, 8 (1918), No. 10, pp. 

 535-542, figs. 2). — Descriptions are given of a chlorosis of the leaves and a 

 fruit rot observed in greenhouse tomatoes in the winter of 1913-14. 



The chlorosis is attributed to unknown environmental conditions surround- 

 ing the plants when the leaves were in a very young or embryonic condition. 

 The fruit rot, which is considered the same as the blossom end rot, was studied 

 at some length but no causative organisms were found present. The hypothesis 

 is proposed that this disease is due to an organism, probably ultramicroscopic, 

 which infects at pollination time only and causes the rotting area to enlarge 

 until such time as physiological processes of the maturing of the fruit render 

 further invasion impossible. 



Tomato wilt (Georgia Sta. Rpts. 1917-18, pp. 1^, 15). — A brief account is 

 given of investigations on the tomato wilt due to Fusarium iycopersici. It is 

 reported that the mode of infection has been studied and has been found to be 

 through the root tips, up the water ducts, and into the stem of the plant. 



Various soil treatments for the control of the disease have been investigated 

 without any promise of success. It is considered that the breeding of wilt- 

 resistant varieties will probably prove the most satisfactory method of control. 



The origin and spread of tomato fruit rots in transit, J. Rosenbaum (Phy- 

 topathology, 8 (1918), No. 11, pp. 572-580, pi. 1, fig. 1). — As a result of a study 

 of diseases occurring on tomato fruits in transit, the author states that, with 

 the possible exception of Phoma rot and leak due to Rhizopus sp., tomato fruit 

 rots found upon the arrival of the car do not originate in transit but in the 

 field and spread from one or more infected fruits included in the pack. The 

 transit and other conditions favoring tlie development of Phoma rot and leak 

 have not been determined, but overripeness of the fruit and bruises and other 

 injuries are considered as predisposing causes. 



From their ability to spread in transit, the author divides tomato fruit rots 

 into three groups, (1) those where the causal fungus can spread and infect 

 adjacent uninjured fruit, (2) those where the causal organism can spread but 

 can infect the fruit only through the stem end or through some break in the 

 skin of the fruit, and (3) those where the fungus is unable to grow through 

 the tomato wrappers and infect healthy tomato fruit. The buckeye rot due to 

 Phytophthora terrestria is said to represent the first group. The second group 

 includes the soil rot (Rhizoctonia sp.), white rot (Scterotium rolfsii), and leak 

 (Rhizopus sp.). Examples of the third group of rots are the nail head spot 

 (Macronporium solani), black spot (Phoma destructiva) , and anthracnose 

 ( Collctotrichvm phomoides) . 



An apple canker due to Cytospora, F. li. Steat<:ns (Illinois Rta. But. 217 

 (1919), pp. ,367-S79, pi. 1, figs. 15).. — A description is given of a canker observed 

 in 1918 on young apple trees. No abrasion or wound seemed to mark the place 

 of the original infection. For the most part the cankered areas exhibited a tan 

 color, the demarcation between diseased and healthy tissues being very sharp. 



