Pine Bluff daily graphic., 1917-03-24
Diseases of Roses and
 How tO Control Them
le rose gardener should understand (

The rose gardener should understand that roses are subject to a number of fungous growths causing serious diseases and that he must ward these off carefully if he would keep his plants in the healthful condition nec- essary for satisfactory growth and the production of blossoms. These fungous parasites rarely kill the plants outright, say specialists of the United States department of agricul- ture, but by their presence the vigor of plants is greatly reduced, the fol- iage may be rendered unsightly, branches more or less distorted or dis figured, and the quality of the blos- soms lowered.
 In considering the fungous diseases Of these plans the fact must be recog- nized that in common with similar diseases of other plants treatments are preventive rather than curative. While thorough and repeated spray ings with a suitable fungicide will in most cases so check the development of the parasite that the disease for the growing season will be in great measure controlled, the full benefit of fungicidal applications can only be se- cured by their early use in the spring, guarding in this way against the re- currence of a disease of the previous season.
 Fungicides to be recommended for rose diseases are Bordeaux mixture, lime e-sulphur, potassium sulphide, and ammonial solution of copper carbonate The lime-sulphur has proved very val uable, especially in controlling mil dew, as it does not injure the foliage of even delicate tea roses.
 Powdery Mildew.
 Powdery lnildew is extremely com mon, few gardens being entirely free from this most destructive of all rose diseases. Wild as well as cultivated roses suffer from it, crimson ramblers being especially susceptible.
 The fungous frequently appears very early in the season on young buds, leaves, and young shoots caus- ing the appearance of a delicate white mildew that becomes mealy after the development of the summer spores. If the attack is severe, the normal de- velopment of the succu1ent young shoots is arrested, the leaves become curled and dcformcd, falling prema- turely, and complete dcfoliation some times results. Later in the season the winter spores develop These spores are capable of pcrsisting through the winter and setting up a new infec- tion in the spring.
 Rose rusts-Rosa rust appears as conspicuous, orange colored swellings on the green parts of rose bushes in the spring or early summer. Later these take deepe, shade and become powdery. Small, circular spots may occur on the leaves. Anthracnose-Ant attacks principally the leaves, but also, to some extent, the branches, causing the appearance of blotches, which later discharge a pinkish mass of spores. The affected leaves are dwarfed and fall.
 Leaf-spot- There are several leaf spot diseases of roses. In most cases the spots have more or less brown ish center with a purplish border. Leaf-blotch-Leaf- -blotch, which is also known as black-spot, ranks next to powdery mildew in frequency of occurrence. Bush roses are more sus- ceptible to this trouble than climbing roses and the attacks are most severe in wet seasons. The first symptoms of the presence of the parasite are ir- regularly shaped, blackish spots with out definite borders on the upper sur face of mature or nearly full grown leaves. These spots may grow to- gether so as to cover almost the en- tire leaf.
 Treatment Generally the Same. Practically all these diseases re- quire the same treatment, which con- sists, in general, of careful spraying for control during the growing season and the cutting of diseased portions of the plant in the fall, followed by more spraying of the shortened plant The diseased wood removed, together with the old leaves and debris under attacks by rusts and leaf spots, the moved and burned even during the growing season.
 For powdery mildew, the control sprayings should be with lime-sul- phur or potassium sulphide. After cutting back in the fall, a similar spray should be made use of. The control spraying should be with g strong Bordeaux mixture. For leaf spot and leaf-blight. the control sprays may be either Bordeaux mix ture or ammonical copper carbonate and the fall spraying should be with i the former.
 Another disease to which roses are subject is canker. A wholly satisfac- tory method of control has not been worked out for this disease. The early symptoms are the appearance ot small reddish patches on the green parts, generally of 1-year-old growth The disease is caused by fungus