Pine Disease. 



[JUNE, 



adopted against this disease is to cut out and burn all affected 

 canes as soon as the disease is detected. 



Gooseberries are sometimes attacked by the fungus Puccinia 

 Pringsheimiana, Kleb., which causes red spots on the leaves. 

 The fungus passes part of its life-cycle on the living leaves 

 of different kinds of sedge. The spores produced on the 

 sedges are scattered by the wind and infect the gooseberry 

 leaves. On the first appearance of the spots the leaves should 

 be sprayed with a solution of 2 oz. of potassium sulphide dissolved 

 in 3 gallons of water. Cutting down sedges growing in the neigh- 

 bourhood checks the disease, but the material cut down must 

 be removed and burnt. 



Another fungus, Gloeosporium ribis, Mont., was sent from 

 Cornwall, where it was infesting gooseberry bushes. If applied 

 sufficiently early in the spring very dilute Bordeaux mixture 

 or potassium sulphide will check this disease. 



Specimens of Exoascus deformans, peach leaf-curl (see Leaflet 

 No. 120, and of Sclerotinia fructigena, brown rot of fruit (Leaflet 

 No. 86), were also received from Minehead and Hailsham 

 respectively. 



Diseased shoots of pine have been sent to Kew for investi- 

 gation on several occasions, and from widely separated 

 districts during past years ; but until 

 A Pine Disease March, 1906, no definite statement could 

 (Diplodia pinea.) be given as to the primary cause of the 

 disease, owing to the unsuitable condition 

 of the earlier specimens received. The reasons for this will be 

 obvious, when the development of the fungus causing the injury 

 is explained. 



The disease is confined to terminal shoots, and is recognised 

 by the yellowing and subsequent shedding of the leaves, 

 followed by the death of the shoot, which dies back for a 

 distance of 6 to 10 ins. These dead shoots are persistent, 

 and, commencing with the year following infection, furnish 

 a crop of fungus spores each season, which, in turn, infect 

 other shoots. 



Diplodia pinea, Kickx., the fungus causing the injury, is a 

 wound parasite, that is, its spores on germination cannot 

 enter through an unbroken surface into the living tissues. 



