VIII. ENEMIES OF FARM CROPS.

TREATMENTS FOR INJURIOUS INSECTS AND FUNGOUS DISEASES OF PLANTS.

By Prof. E. S. GOFF, of Wisconsin Experiment Station.

The value of the following treatments for preventing injury to crops from insects and fungous diseases has been proved by abundant experience. It is essential that the treatments be given promptly and thoroughly. In the case of fungous diseases, it is generally essential that the applications be made before the disease appears, since they are preventive, rather than curative. The treatments considered most important are printed in italics. As a rule, those not so printed need be given only in seasons or localities in which the attack is serious.*

Formulas.

No. 1. Bordeaux Mixture.-Place 5 pounds of copper sulfate in a cloth sack and suspend this over night in a wood vessel containing 4 gallons of water, immersing the sack. In another wood vessel slake 4 pounds of fresh lime in as many gallons of water. When the lime is cool, pour it and the copper sulfate solution into a barrel and add enough water to make 45 gallons. Apply at once with a force-pump, with spraying nozzle, stirring frequently during the application.

No. 2. Ammoniacal Copper Carbonate.-Dissolve I ounce of copper carbonate in 3 pints of strong ammonia and add this solution to 25 gallons of water. Apply as in No. I. No stirring is required.

No. 3. Copper Sulfate Solution.-Dissolve, as directed in No. I, I pound of copper sulfate in 15 gallons of water.

as in No 2.

Apply

No. 4. Stir 4 ounces of Paris green in 40 gallons of water, and add pound of fresh lime, slaked in 2 quarts of hot water. Apply as in No. 1.

No. 5. Bordeaux Mixture (No. 1), with Paris green added at the rate of 1 ounce to 10 gallons. Apply as in No. 1.

*The following scheme for treating crops is after a plan published by the late Mr. E. G. Lodemann of Cornell University, in Trans, N. Y. State Agricultural Society for 1893, pp. 176-179.

No. 6. London purple, 4 ounces, very thoroughly mixed with 25 pounds of land plaster. Apply with a sprinkling-box.

No. 7. Mix 1 ounce of fresh powdered white hellebore in 3 gallons of water. Apply at once with force-pump or sprinkling pot.

No. 8. Kerosene Emulsion.-Dissolve pound hard, or I quart of soft soap in 2 quarts of boiling water; place I pint of kerosene in a tin can; pour the boiling-hot solution into this, cork, and shake rapidly for 1 minute. Before using, dilute with its own bulk of warm soft-water. Apply as in No. 2.

No. 9. Mix 1 pound of fresh Pyrethrum powder with an equal bulk of air-slaked lime in a bottle or tin can; cork tightly and leave 24 hours before use. Apply in still air, with sprinkling-box or powder-bellows.

No. 10. Air-slaked lime applied with a sprinkling-box.

No. II. Cut small cards from thin tarred paper, slit one side to the centre, and make a short cross-cut near the end of the slit, as in drawing.

+

No. 12. Corrosive Sublimate Solution.-Dissolve 2 ounces of corrosive sublimate in 2 gallons of hot water, and pour this solution into 15 gallons of cold water. Use wood, earthen, or glass vessels.

No. 13. Potassium Sulfid Solution.-Dissolve ounce of potassium sulfid (liver of sulfur, sulfuret of potassium) in I quart of warm (not hot) water, and add this solution to 3 quarts of cold water. Apply as in No. 2.