10 May, 1919.] 



Api^le Culture in Victoria. 



291 



In making the combination mixtures no standards are observed, 

 but care should be exercised that the fungicide, particularly the lime- 

 sulphur, be not too strong, as the arsenate of lead ■v\Then incorporated 

 in the mixture seems to intensify its caustic properties. The applica- 

 tion of such a deleterious spray often causes injury both' to the foliage 

 and to the fruit. Because of the frequency of scorching experienced 

 by growers who have experimented with the combination mixtures 

 during the last two years, some have discarded these, and have reverted 

 to the practice of using the separate sprays. Owing to the varying 

 conditions under which these are made up, the actual chemical change 

 effected by combining the fungicide with the insecticide is not generally 

 understood. If this be not determined by a chemical test, then a weak 

 mixture should be at first used, and 'by practical experiment increased 

 in 'strength until a suitable spray is obtained. 



Jonathan bloom, showing con- 

 dition when first spray was 

 given. 



Plate 195. 



Jonathan bloom, showing condition 

 when second spray was given. 



KooT Fungus (Abmillaria Mellea). 

 This fungus is indigeneous to Australia, and lives on the roots of 

 native forest trees and shrubs. It may be found on any class of soil 

 infecting introduced trees and plants, and no kind of fruit tree is im- 

 mune from its attack. In one stage of its development the (parasite 

 may appear as thin white filaments on. the bark near the points of the 

 small roots. Later it may be present as a whitish felty substance living 

 in the cambium beneath decaying bark. It is best known and most 

 easily recognised, however, when numerous thin black strands, fastened 

 to the bark of a large root, give it the appearance of being enclosed iu 

 wire netting. For this reason it is sometimes termed " wire fungus," 



22 



