14 



and shoots of the new growth. The spring attack is usually mild 

 and apt to be neglected, which may lead to serious results. 



Preventive Measures. In the case of mildew, infection is due to 

 the winter spores that are produced on the white cottony mildew 

 growing on the shoots. Cleanliness in this case therefore consists of 

 carefully removing * every trace of the white felted substance from 

 the shoots, stem and fruit, and burning it. This should be done 

 as early in the season as possible, otherwise the winter spores will 

 fall to the ground, where they will survive the winter and be a source 

 of trouble next year. 



The spawn of many kinds of parasitic fungi is perennial in the 

 tissues of the plant attacked ; in other words, when the plant is once 

 infected the spawn remains in the living condition in the plant from 

 year to year ; this, however, is not so in the case of mildew or rose 

 rust. During the winter a given rose tree, however seriously it may 

 have been attacked by either or both of these diseases during the 

 summer, is perfectly free from disease, and will remain so unless a 

 new infection takes place. 



Spraying. It is important to note that spraying is purely pre- 

 ventive in its action. No disease can be killed by spraying. Spray 

 with a solution of potassium sulphide, popularly known as " liver of 

 sulphur," i oz. in 3 gallons of rain water. This is an excellent fungicide 

 against rose mildew. Later in the season, when the second attack 

 comes on, a slightly stronger solution may be used to advantage. All 

 bushes which have been attacked by any fungus should be thoroughly 

 sprayed with a solution of sulphate oj copper, I oz. in 2 gallons of 

 water ; the surrounding soil should be similarly treated. It is im- 

 portant to remember that this wash should be applied during mid- 

 winter before the leaf buds begin to swell, otherwise the foliage will 

 be destroyed. 



The washes should be applied with as fine a spray as possible, 

 and the spraying should commence at the first sign of mildew. 



Rose Rust. This fungus appears on the leaves and wood in the 

 form of deep orange powdery patches.. All leaves bearing winter 

 spores should be collected and burnt. Winter spores do not form 

 on the wood, but only on the leaves, which are covered with small 

 black projecting points. If these are collected and burnt it will lessen 

 the attack the following year considerably. Spray as advised for 

 mildew. Two or three applications will be necessary. Take care 

 that the solution gets at the inside of the bush. If the rust spores 

 appear on the wood they may be treated with a solution of methylated 

 spirit and water. 



Black Spot. This disease is confined to the foliage, and as a rule 

 is in evidence before midsummer. It appears in the form of black 

 spots almost circular in outline. This disease often does very con- 

 siderable damage to rose trees. All diseased leaves should be removed 

 and burnt. Commence spraying with Bordeaux mixture early in 

 * That is, by pruning away parts showing the fungus. F. J. C. 



