566 EXPERIMENT STATION RECORD. 



sufficient strength to secure partial immunity of the crop will not so 

 greatly decrease the yield as to render their use impracticable. 



Blight, burn, or scald of tomato plants, W. E. Britton ( Connecti- 

 cut State Sta. Rpt. 1896, pp. 232-234). — A report is given of a blight 

 which attacked tomatoes grown under glass. The disease began at the 

 tips of the leaves and gradually extended until nearly the entire leaf 

 was dead and dry. The upper most rapidly growing parts remained 

 longest unaffected, but finally all except the youngest leaves showed 

 the presence of the disease. 



Specimens of the diseased plants were submitted to B. T. Galloway, 

 of this Department, and L. H. Bailey, of Cornell University, and by 

 them the disease was considered to be the same as that of the burn or 

 sunscald which results from insufficient water supply to the roots, and 

 is most noticeable upon plants when bright sunshine follows cloudy 

 weather. However, in the case of the present attack the blight made 

 visible progress under a continuously and densely clouded sky. As a 

 possible explanation of the disease under these circumstances it is sug- 

 gested that probably cold currents of air under the benches chilled the 

 roots to such an extent that the plants were not sufficiently provided 

 with water. 



A destructive fungus disease of tobacco in South Carolina, 

 W. C. Stukgis (Connecticut State Sta. Rpt. 1896, i>j>. 273-278, pi. 1, 

 figs. 3). — A disease which was found occurring on half-cured wrapper 

 tobacco leaves received from South Carolina is figured and described. 

 It appears as brown circular spots from the size of a pin head up to 

 half an inch or more in diameter scattered thickly over the upper surface 

 of the leaves. These brown spots are sometimes marked with whitish 

 centers bordered by a darker slightly raised line. Toward the tips 

 and edges of the leaves they frequently coalesce forming large brown 

 blotches of irregular outline. Microscopic examination of the diseased 

 spots showed that they were invaded by a species of fungus which has 

 been described by Ellis and Everhart as Gercospora nicotiancc. 



The author briefly describes various other leaf diseases of tobacco 

 and compares them with the one under discussion. As probable 

 preventive means he suggests Bordeaux mixture, ammoniacal copper 

 carbonate solution, or flowers of sulphur. He believes it possible that 

 judicious fertilizing might so far increase the vigor of the plants as to 

 render them less subject to the disease if not exempt from its attack, 

 analyses of the fertilizers used having shown a deficiency in potash. 



Experiments on the prevention of potato scab, W. C. Stuikjis 

 (Connecticut State Sta. Rpt. 1896, pp. 246-262). — The author conducted a 

 series of experiments to test (1) the comparative value of corrosive 

 sublimate and lysol for the prevention of scab upon potatoes; (2) the 

 comparative value of corrosive sublimate, lysol, and sulphur in prevent- 

 ing scab on infested lands; and (.'>) the comparative effect of fresh and 



