554 EXPERIMENT STATION RECOED. [Vol.37 



Lanas may attack in any one of four forms, namely, entire young plantlets on 

 the seed bed, the crown at any age, the upper part of the stalk of grown plants, 

 or the leaves thereof. Comparisons are made with tobacco diseases elsewhere. 



Spraying affected plants and soil with fungicides and removal of affected 

 plants are recommended. 



Gummosis in tobacco, H. Jensen {Proefstat. Vorstenland. Tabnk [Dutch 

 East Indies}, Meded. 6 {19U), pp. S-10, fig. i).— The author gives the results 

 of studies on the relation between lanas in the Crown lands and gummosis at 

 the Deli station. These diseases may prove to differ but little, except in the 

 greater severity noted in the former case. 



Experiments carried on simultaneously by the author in the Crown lands 

 and by J. A. Honing at Deli seemed to indicate that a strain of Kanari tobacco 

 is somewhat resistant to diseases of this type, attaining more vigorous growth 

 than either of the other two strains tested. 



Leaf roll in tomatoes, H. T. Gussow (Phytopathology, 6 {1916), No. 6, p. 

 447). — The author reports a disease of tomatoes at Lethbridge, Alberta, which 

 shows phenomena closely resembling the leaf roll in potatoes, and he suggests 

 that the disease is similar to one previously described from Austria by G. Kock, 

 in which no parasitic organism was found. The Canadian specimens are said to 

 have appeared sound with the exception of the rolling of the leaves. 



Watermelon diseases, W. A. Okton (U. S. Dept. Agr., Fanners' Bui. 821 

 {1911), pp. 18, figs. 11). — Popular descriptions are given of a number of diseases 

 to which the watermelon is subject, together with suggestions for their control. 

 Among the more common and destructive diseases are watermelon wilt, root 

 knot, anthracnose, and stem-end rot. Descriptions are also given of several 

 minor diseases. 



The varietal relations of crown gall, J. K. Shaw {Science, n. ser., 45 (1917), 

 No. 1167, pp. .'(61. 462). — Attention is called to the various forms of crown gall 

 occurring on apple trees, and the autlior raises the question as to whether the 

 different forms may not be due to varietal differences in the host plants. Dur- 

 ing the past few years several thousand apple trees of many varieties have 

 been propagated on their own roots by means of the common whip graft, the 

 seedling nurse I'oot being cut off at the end of about two seasons' growth, 

 thus leaving the scion growing on its own roots. It has been observed that 

 where crown gall is present on such trees there is a tendency for a given variety 

 to have only a single form of the disease. The Jewett shows usually the hard 

 form of the gall, the Red Astrachan the simple form of the hairy root, and the 

 Oldenburg the wo(»lly knot form with many soft fleshy root gpi^^wttis. Some 

 varieties on their own roots seem to be largely if not entirely immune to thlg 

 disease, and it is suggested that this fact may offer a solution of the problem 

 of the prevention of crown gall. 



Fire blight, F. LiStourneau {Ann. Rpi. Quebec Soc. Protec. Plants [etc.], 8 

 {1915-16), pp. 42-45). — Fire blight is said to be the worst disease of fruit 

 trees in the Province of Ontario, attacking chiefly pear, but also apple, quince, 

 and even plum, hawthoru, and mountain ash. The disease is said to be 

 peculiar to North America, occurring all over the United States and in 

 Ontario, Quebec, and British Columbia. The various forms and effects of 

 attack are discussed, as are also the life cycle and means of control. 



Dieback of apple trees, caused by Cytospora leucostoma, V. A. van der Bijl 

 (Byt.) {So. African Jour. Sci.. 12 {1916), No. 12. pp. 545-557, pis. 6, figs. 4).— 

 The author describes a serious dieback of apple attributed to C. leucostoma, 

 which is said to appear also in the same, or a closely related form, on peach, 

 plum, and apricot trees. The fungus grows well in the laboratory on a number 



