234 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Another matter to be considered when dealing with Carnation 

 pests and diseases is the conditions under which the plants are grown. 

 A Carnation plant must have light and air. There is no known 

 substitute for that. If you coddle Carnations unduly you ruin them. 



That brings us to another vitally important matter in the cultiva- 

 tion : the soil or compost in which they are grown. A soil too rich, 

 or the addition of leaf-mould if persisted in, will cause deterioration 

 in the plants. A Carnation enjoys a firm, sweet, moderately open soil. 



The special diseases of the Carnation are : — 



Stem-rot. — Of recent years this has become perhaps the most 

 common disease among Carnations. It gives the grower no warning, 

 the plants' stem diseasing just above the soil. This disease is more 

 common among Carnations which are propagated by means of cuttings 

 than in layers. Some growers contend that it is hereditary, but we do 

 not agree with this contention, although certain varieties are more 

 subject to it than others. In our opinion, it can be prevented but not 

 cured. We have proved that it is brought about by two causes, the 

 principal one of which is rooting the cuttings in unsuitable sand, such 

 as a sand that contains iron in large quantities, or one very fine in 

 texture which practically turns to mud when watered, and settles 

 down like cement. This quickly turns sour. Also, if the cuttings 

 are allowed to remain too long in the sand after rooting they become 

 hardened and checked. Deep potting will also cause stem-rot : in 

 fact, we have found that stem-rot commences at a buried joint, and 

 it is most essential that as little of the stem of the plants should be 

 buried as possible. 



Fungus Diseases on Carnations. — These are looked upon as the 

 bane of Carnation life. The principal diseases are Rust (Uromyces 

 caryophyllinus) , Spot (Septoria dianthi), and Fairy Ring Spot (Hetero- 

 sporum echinulatum (fig. 37). What I particularly wish to point out 

 here is that under correct cultivation, if the plants are given 

 normal treatment, no fungus diseases will trouble you. A close, 

 moist, humid atmosphere will encourage fungus disease, but a fresh 

 buoyant atmosphere will destroy it. Many of the remedies advised 

 simply aggravate the disease, ruin the plants, and destroy the 

 bloom upon the foliage. This does not apply to plants grown under 

 glass only, but also in the open. A simple and effective method for 

 combating a fungus disease On Carnations is to cut off all affected 

 leaves and burn them, and dust the plants with a mixture of sulphur, 

 air-slacked lime, and copper sulphate, previously prepared and treated. 

 This destroys the spores of the disease without affecting the foliage of 

 the plants. During the summer months, when the atmosphere 

 is hot and dry, we use an occasional spraying of the plants with a 

 liquid preparation of copper, ammonia, and distilled water, as a 

 preventive. 



Bacteriosis or Stigmonosc (Bacterium dianthi). — In appearance, 

 this is simply yellow, translucent spots on the leaves, which are de- 

 stroyed cells, and are seen very plainly when the leaf is held up to the 



