128 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



be necessary, and the formidable task of obtaining funds for 

 the acquisition of a site and the erection of buildings remains. 

 A building fund is being started, and it is hoped that this 

 great undertaking will not suffer from lack of support on the 

 part of benefactors who have at heart the welfare of the 

 Empire in general and the cause of forestry in particular. 



13. A Dieback, and Bark Disease of Willows, 

 attacking the Young Twigs. 



By N. L. Alcock. 



In October 1924 rods of a willow, apparently Salix alba var. 

 vitellina, were sent to the Royal Botanic Garden, Edinburgh, 

 from High Blantyre, suffering from a disease that killed the tips 

 and caused black blotches on the stem, and an extensive die- 

 back. A parasitic fungus was present, and after examination 

 it was decided that the disease was that known on the Continent 

 as bark scorch of willows. 



This disease is caused by the fungus Fusicladnim saliciperdum 

 (All. and Tub.) Tub.,i which is very closely related to the 

 fungus causing apple scab, Fusicladium dendriticuin^ Fckl. 

 {Venturia inaequalis Aderh),- The perfect stage of Fusicladium 

 saliciperdum is said to be Venturia chlorospora (Ces.) Karst.^ 

 This form, as far as I know, has not been seen in Great 

 Britain. The disease attacks many species of willows, including 

 Salix alba, S. aiirita, S. caprea, S. cinerea, S. cuspidata, S.fragilis, 

 S. mollissima, according to Rabenhorst ; ^ also S. ?tigricans and 

 S. pentandra according to Tubeuf.^ It has been noted in Bavaria 

 and other parts of Germany, in Denmark, and recently in 

 the Netherlands,^ where it has caused a disease particularly 

 of the weeping willow. The ordinary weeping willow in the 



^ J. Lind, Danish Fungt, pp. 212, 520. 



-Salmon, Reports S.E, Agricultural College, Wye, Economic Mycology, 

 July 1907, p. 17. 



^ J. Lind, Ann. Mycologici, iii., 1905, p. 43. 



•* Rabenhorst, vol. 8, p. 776. 



^ Tubeuf, Freiherr C, "Das Triebsterben der Weiden,"" Arb. Biol. 

 Abt. Land ttnd Forsiiu. Kaiserl. Gesundheit samtes 1, 1902, pp. 567-570. 



•^ Schwarz, Marie Beatrice, "Das Zweigsterben der Ulmen., Trauer- 

 weiden und Pfirsich baume," Mededellingen u.h. Phytopathologisch 

 Laboratorium Willie Commelin Schollen, Dec. 1922. 



