FUNGOID PESTS 



attention to some of the more common of these Fungoid Pests, and will 

 group them under four heads, viz. — 1. Roses ; 2. Orchard and Fruit Garden ; 

 3. Ornamental Shrubs; 4. Forest Trees. 



I. DISEASES OF ROSES. 



Rose Mildew, Sphcerotheca pannosa, is undoubtedly the most prevalent 

 and destructive of all Rose pests. Its dirty-white felted mycelium of inter- 

 woven threads clothes the leaves, shoots and flower-stalks of all kinds of 

 Roses. The mycelium sends up short branches, which produce conidia attached 

 to each other in a chain. They are produced in rapid succession during the 

 summer months, and, unless kept in check by frequent spraying or the use 

 of sulphur, will soon give rise to an epidemic beyond all control. No fungoid 

 disease can be cured by spraying, but it may be prevented from extending, 

 by killing the spores which alight on the leaves. 



As the season advances winter spores are produced. They consist of 

 small dark brown globose receptacles scattered about upon the whitish 

 mycelium. When mature each receptacle encloses a single globose trans- 

 parent sac, or ascus, containing numerous spores which will germinate in 

 the following spring. This winter fruit is found in the mycelium growing 

 on the young wood, or rarely on the fruit, but not on the leaves. It is 

 essential that every patch of mycelium should be carefully scraped off and 

 burned, doing this early in the season, before the spores have a chance 

 of falling to the ground. 



Rose Rust, Uredo Bosce, occurs during the summer on the leaves, petioles, 

 and stems of wild and cultivated Roses, bursting through the cuticle as 

 an orange-coloured powder. The patches on the underside of the leaves are 

 small, or may coalesce to form a larger patch, while on the stems they 

 may extend to an inch in length. When the rust disappears wounds or 

 canker spots remain, which favour the growth of other fungi. 



The rust patches on the wood may be treated with a solution of equal 



parts of methylated spirit and water, rubbing in with a piece of sponge. 



lxiii g 2 



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