Pla nt- Diseases . 



5i 



Grape (Powdery Mildew), continued. 



hot pipes. Any of the sprays of copper compounds are 

 specifics. 



Ripe-Rot (Gloeosporium fructigenum, Berk.). — See under Apple- 

 The treatment for black-rot is efficacious for this. 

 Hollyhock. Rust (Puccinia Malvacearum, Mont. ) . — Appears upon 

 leaves of hollyhocks and a few related plants in small, light 

 brown patches. Introduced from Europe, and becoming com- 

 mon in this country. 



Remedies. — To destroy the plants is the only general method 

 yet employed to prevent the spread of the disease, but some 

 of the copper fungicides may be used. 

 Lettuce. Mildew {Pcronospora gangliformis, DeBary). — A deli- 

 cate mildew, attacking lettuce-leaves and causing yellow or 

 brown spots, and finally killing the leaf. 



Preventives. (According to Maynard.) — Grow at a low 

 temperature (35° to 40° at night, 50° to 70° during day) ; give 

 abundance of plant-food; give abundance of water, but 

 apply it in morning and bright days only; avoid sudden 

 extreme changes of temperature. 



Remedy. — Fumes of sulphur. 

 Maple. Leaf-Spot (PlujUosticta cice?~icola, C. & E.). — Attacks the 

 leaves of red, silver, and striped maples in spring, causing 

 them to become spotted and unsightly, and lessening the 

 vigor of the tree. 



Remedies. — Rake and burn the leaves in autumn. When 

 the leaves are two -thirds grown spray with sulphide of 

 potassium or copper fungicides, and repeat every three or 

 four weeks as long as necessary. 

 Onion. Rust (Peronospora Schleideniana, Unger). — The leaves 

 turn yellow about the time the onions begin to bottom, or a 

 little later, and wilt and die. 



Remedies. — Grow on land not infected, and destroy all af- 

 fected onions. Spray early with copper fungicides. 

 Smut (Urocystis cepulce, Frost). — Attacks the first leaf or 

 leaves of seedling onions, producing dark irregular spots, 

 and killing or weakening the plants. 



Remedy. — The sulphur and lime mixture drilled into the 

 ground with the seed ; about an ounce of the mixture to 50 

 feet of drill. 



