52 EXPERIMENT STATION RECORD. [Vol.41 



smut hns not been adequately studied as to its life history, and its mode and 

 habit of attack are not settled. 



The nomenclature of these smuts is discussed in connection with descriptions 

 of diseases and fungi. 



The copper sulphate remedy is the only one considered applicable under local 

 conditions, concentrations of from 0.5 to 3 per cent being considered as both 

 safe and effective. 



On the mode of infection and prevention of the smut disease of sugar cane, 

 S. L. A.TKEKAR (Agr. Jour. India, 11 (1916), No. S, pp. 288-295, pi. i).— The 

 author has carried out studies suggested by remarljs made by Butler in a paper 

 previously noted (E. S. R., 18, p. 450), attempting to ascertain how infection 

 u.sually takes place in the field in case of sugar-cane smut and testing the effi- 

 cacy of copper-sulphate treatment of sugar-cane sets before planting. These 

 experiments were carried through 3 years in the neighborhood of Poona, where 

 smut had appeared sporadically for some years, particularly on some thin 

 varieties. 



The results show that the disease may be carried by canes not obviously 

 diseased if taken from stools some portions of which are affected. The fungus 

 may be demonstrated in a side shoot not over 6 in. in length from an infected 

 shoot ; also in the tissues of the dormant buds in a diseased cane. Smut origi- 

 nating in diseased sets usually appears within 3 to 5 months after planting. 

 Infection by spores adhering to sets does not usually become apparent until 

 the crop is approaching maturity. No direct proof was obtained regarding 

 probable infection of shoots by aerial transmission of spores and tlie forma- 

 tion of dormant mycelium in such shoots. 



Steeping in copper-sulphate solutions is useless and does not check the dis- 

 ease. The practical control methods suggested are destruction of diseased 

 canes and careful avoidance of infected stools for propagation purposes. 



Tomato spraying experiments at Riverton, N. J., W. H. Martin {New Jer- 

 sey Stas. Rpt. 1917, pp. 540-561, pi. 1). — A report is given v»f spraying experi- 

 ments for the control of the late blight of tomatoes carried on in 1917 in cooper- 

 ation with the U. S. Department of Agriculture and a prominent tomato grower. 

 The fungicides used consisted of Bordeaux mixture, the formula of manufac- 

 ture of which was varied and to which in some cases resin fish-oil soap was 

 added, a copper-sulphate mixture with the fish-oil soap, and a copper-sulphate 

 soap mixtui'e. 



As a result of the investigation, it is claimed that late blight of tomatoes, 

 caused by Sepforia lyeopcrsici, can be controlled by thorough spraying at the 

 proper time. All of the fungicides used gave increased yields over the check 

 plats and controlled the late blight. Standard Bordeaux mixture, while not 

 giving the best control, gave the greatest increase in yield over the check plats. 

 The copper-soap mixture gave good results, and, on account of its low cost and 

 ease of preparation, it is thought that it should be given serious consideration. 

 As a result of the season's work it is believed that spraying tomato plants in 

 the seed bed in New Jersey is unnecessary but that the first application should 

 be made not later than July 1. It was also ascertained that if all the leaves 

 are held on the plants until frost a large part of the fruit formed will not 

 ripen. In connection with these experiments different forms of spray machines 

 were tested and while there was little difference in the two types compared, 

 the traction sprayer, due to its low cost of upkeep, is considered the better. 



The effect of late applications on the yield and ripening of tomatoes was 

 investigated. From the results obtained, it is considered that the value of 

 spraying late tomatoes is questionable. 



