1917] DISEASES OF PLANTS. 551 



somewhat unfavorable to the spread of fungus diseases in this region. The 

 extreme dryness favored the spread of a root disease of sugar cane due to a 

 weakly parasitic Marasmius. Pithy deterioration of White Tanna cane, ap- 

 parently due to a bacterium, was prevalent in certain districts, and some other 

 varieties were affected. The gumming disease of sugar cane noted during the 

 early part of the year (E. S. R., 34, p. 843) did not spread after May. Red rot 

 {CoUetotHclium falcatum) occurred in September and October on one estate, 

 following an attack by borers (Diatrcea striatalis). Smut (Ustilago sacchari) 

 came under observation here this year for the first time. 



The leaf disease of Arabian coffee due to Hemileia vastatrix was less common 

 this year than usual. It was controlled by Bordeaux mixture in one instance. 



The manioc leaf and stem disease {Glceosporium manihotis) was again com- 

 mon in some localities, causing defoliation in September. Some recently intro- 

 duced varieties appear to be somewhat resistant to this disease. 



A leaf spot of pistachio, due to Uredo arachidis, was again observed. The 

 most serious leaf spotting of pistachio was due to Cercospora personata, which 

 caused much damage to introduced varieties. 



Leaf disease (Phytophthora infestans) of potato was common during July to 

 September, inclusive. Cooperative spraying gave encouraging results. Spraying 

 should begin early, and should continue at intervals of 8 to 10 days, owing to 

 heavy dews in July and August. 



Tomatoes raised from imported seeds suffer with leaf disease, but the local 

 pomme d'amour is measurably resistant. Sleeping disease (Fusarium lyco- 

 persici) and a collar rot are common and injurious. Egg fruits {Solarium 

 melongena) were badly affected with stem blight during March and April. A 

 root disease of she oak {Casuarina equisetifolia) is under investigation. 

 Turkish tobacco at Pamplemousses failed on account of attacks by an Erysiphe. 



Lists are given of garden plants examined during the year, diseases noted, 

 and causative organisms. 



Report of the microbiologist, H. M. Nicholls (Tasmania Agr. and Stock 

 Dept. Rpt. 1913-14, pp. 28, 29). — In a brief report which also deals with insect 

 pests, the author notes the first appearance in Tasmania of cruciferous clubroot 

 (Plasmodiophora brassicce) and of cabbage leaf spot (Glceosporium concentri- 

 cum). Considerable injury is done by a rust causing dieback in orchards. 



The principal potato diseases noted were dry rot (Fusarium solani) and scab 

 (Oospora scabies). The dry rot due to Spondylocladium atrovirens was noted 

 here for the first time. 



Notes relating to the Gymnosporangia on Myrica and Comptonia, B. O. 

 Dodge and J. F. Adams (Mycologia, 9 (1917), No. 1, pp. 23-29, pis. 2, fig. 1). — 

 A study has been made, vrith inconclusive results, regarding the relationships 

 of a fungus found in 1916 to cause certain changes, which are described, in 

 Comptonia. It is thought that the fungus may prove to be a relative or member 

 of the genus Gymnosporangium, possibly identical with G. myricattim or 

 2Ecidium myricatum on Myrica. 



Studies in the life histories of some species of Septoria occurring on Bibes, 

 R. E. Stone (Phytopathology, 6 (1916), No. 6, pp. 419-427, figs. 2).— Additional 

 investigations have confirmed the conclusion of the author that S. ribis has 

 for its perfect stage Mycosphcerella grossulariw (E. S. R., 36, p. 246). The 

 perfect stage has been reported on R. grossularia and R. nigrum in Europe 

 and possibly on R. rubrum, but in North America it has been collected only on 

 R. nigrum. M. aurea n. sp. is described as the perfect stage of S. aurea. This 

 fungus is said to be more limited in its range, being known only in North 

 America on R. aureum. 



