DISEASES OF PLANTS. 155 



PlowrUjld'ia morhosa^ was of an entirely different orig-in. It has been 

 considei-ed in Europe to be due to the action of frost, and has re- 

 ceived little attention in this country. Peach diseases — winter injury, 

 leaf curl, yellows, fruit rot, leaf-tip burn, powder}" mildew, and scab. 

 Pear diseases — scab, leaf blig-ht, fire blight, bod}' blight or rough 

 bark, and winter injury. The body blight or rough bark is generally 

 considered to be a form of fire blight due to Bacillus aniylovorus^ but 

 according to recent investigations of the station it is now thought to 

 be caused b}^ the apple canker {Sj^JireropsiH inaloram)^ an account of 

 which is given in Bulletin 163 of this station (E. S. R., 12, p. 61). Plum 

 diseases — black knot, fruit rot, leaf blight, and leaf curl. Quince dis- 

 eases — fruit spot, leaf blight, and fire blight. Raspberry diseases — • 

 anthracnose, rust, root galls, winter injury, cane blight, and leaf spot. 

 The cane blight is apparently due to some species of Phoma, but as 

 yet no inoculations have been made. Notes on the leaf blight and 

 sun scald of strawberries complete the bulletin. 



A sugar-cane pest in Madras, C. A. Benson {Indian Agr., 25 

 {1900), X<>. 1,2>I>- 1^~I^)- — Notes are given on an investigation begun 

 toward the end of 1897 to determine the cause of a disease of sugar 

 cane. The disease was found not to be of recent origin, and was dis- 

 tributed rather generally throughout the region in which sugar cane 

 was produced. The disease exhibited all the symptoms characteristic 

 of an attack by Tricliosplimria saccJiari, different stages in its life his- 

 tory l)eing known as root fungus, rind fungus, etc. Canes but slightly 

 affected show no external signs of disease, but transverse sections 

 show one or more bright red spots in some of the internodes, and if 

 these are followed by longitudinal sections they appear as red streaks 

 which branch at the nodes. Where the disease is more advanced, the 

 coloration extends to the ground tissue, so that any section may show 

 red patches. When the disease is still further advanced, the nodes 

 and later other portions become black, the leaves wither, and the 

 entire cane dries up. 



The methods adopted in India for growing sugar cane seem to be 

 such as to foster the spread and continued presence of this disease. 

 Some attention was paid to the extent in which different varieties were 

 affected, and it is stated that a comparatively slender cane known as 

 Yerra seems to suffer less than others. It probably owes its partial 

 immunity to the thick rind and to the fact that it does not crack to 

 any great extent. 



The author believes that although the disease at present is epidemic 

 in Madras, there is no occasion for alarm, as it has been known there 

 for at least 30 years, sometimes severe and at other times ahnost dis- 

 appearing. Attention to cultivation, destruction of litter, and aban- 

 doning the growth of cane for a few years, together with giving up 

 the practice of ratooning altogether would probably check the disease. 



