THOROUGHNESS. Great care should be taken to make the application thorough in every respect. The material should not only be well agitated but applied to every portion of the tree. Most of the unsatisfactory results in FIG. 305.-Spray nozzles. a, side cyclone, a splendid nozzle for spraying trees and plants infested with red spiders or mites; b, angle and c, straight "Jumbo" nozzles, excellent for general work. spraying are due to inefficient and careless operators. Every portion of the tree should be thoroughly drenched. The tips of the side branches and the tops should receive the same careful consideration as is usually given to the trunk. No one can hope for good results who neglects this important phase of spraying work. TIME OF APPLICATION. Of course the time of application varies somewhat with each particular pest, but there is a time for every one. The grower should carefully ascertain when that time is and do the work then and not wait until his efforts bring little or no avail. Those who spray for codling moth can appreciate what the time element means. APPROXIMATE COST OF SPRAYING MATERIALS. The following prices have been secured from a large number of dealers and represent the average retail cost of these materials. Such prices, though exceedingly variable, enable the grower to arrive at the approximate cost of a spray and also show that it is desirable to buy in as large quantities as possible. Commercial Lime-Sulphur Solution. In lots of from 1 to 25 barrels. In lots of 20 barrels__. In lots of 100 barrels. $10 00 per barrel. 9 00 per barrel. 8 00 per barrel. There is an extra charge of from $1.00 to $1.50 on each barrel which if returned is refunded. These prices are f. o. b. at point of destination. Copper Sulphate (bluestone). The price of this commodity is exceedingly variable but at present is as follows: Crude Carbolic Acid (15 to 20 per cent phenols). Crude oil may be purchased at from 3 to 5 cents a gallon. Pyrethrum (powdered). In 1 pound lots_ 36 cents per pound. 31 cents per pound. 32 cents per pound. cents per pound. 30 CALIFORNIA SPRAY CHEMICAL COMPANIES. Balfour Guthrie Company, San Francisco, California. Bean Spray Pump Company, San José, California. Braun Corporation, Los Angeles, California. Braun-Knecht-Heimann, San Francisco, California. California Drug and Chemical Company, Los Angeles, California. Kirk-Geary, Sacramento, California. Mountain Copper Company, San Francisco, California. CALIFORNIA SPRAYING MACHINE COMPANIES. Baker & Hamilton, San Francisco, California. Bean Spray Pump Company, San José, California. Household Supply Company, San Francisco, California. *FUMIGATION. Fumigation consists in the generation and uses of gases to kill destructive insect pests. Formerly such practices were limited to the uses of carbon bisulfid, sulphur dioxid and tobacco fumes. The use of hydrocyanic acid gas in citrus orchards has lately been so perfected as to become of very great importance and has opened up a remarkable field in the control of orchard pests. CARBON BISULFID. Carbon bisulfid is a liquid which evaporates into a heavy, highly explosive gas. It was first used for fumigating beans, grains or cereals for weevils, and is still a very efficient method of controlling such pests. In handling the liquid great care should be taken to keep it away from a flame on account of its being highly explosive. *For further information relative to fumigation, see Bull. No. 76, Bur. Ent., U. S. Dept. Agrel., by A. W. Morrill. Bull. No. 79, Bur. Ent., U. S. Dept. Agrel., by R. S. Woglum. Bull. No. 90, (Part I.) Bur. Ent.. U. S. Dept. Agrel., by R. S. Woglum. For Storehouse Pests. Before fumigation is begun care should be taken to see that the room or container is made as tight as possible. The temperature should be 70 deg. Fahr. or above, as poor and unsatisfactory results are sure to follow even excessive doses at a lower temperature. In a tight compartment five pounds to every thousand cubie feet gives excellent results in killing weevils. If the compartments cannot be made tight, increase the amount of carbon bisulfid. For Root Pests. In the field this liquid is used to kill root pests as woolly aphis, black peach aphis, phylloxera, grubs, maggots, etc., but is practical only in sandy or porous soils. For a small plant a single hole is made near the base and a teaspoonful of the liquid poured in and the hole covered to prevent outside evaporation. For larger plants several or many holes should be made, deep enough to allow the liquid to evaporate around the infested roots. A syringe-like instrument is sometimes used to inject the liquid around the roots. For Borers. Injections of carbon bisulfid into the burrows of wood borers and stopping the entrance of the burrows will kill all the insects reached by the gas. For Ants and Wasp Nests. A small amount of this liquid poured into underground nests of ants, wasps, etc., will suffice to destroy the inhabitants very quickly. TOBACCO FUMES. For very tender house and greenhouse plants infested with plant lice, thrips, etc., it is sometimes advisable to fumigate them with slowly burning tobacco, but even in such cases hydrocyanic acid gas is replacing the more uncertain tobacco fumes. HYDROCYANIC ACID GAS. Hydrocyanic acid gas is generated by the addition of diluted sulphuric acid to sodium or potassium cyanide. The generation is made. in an earthenware jar, the gas being confined in a fumigation house or, if the work is being done in the orchard, in a tent thrown over the tree. For many years the methods of fumigation depended entirely upon each fumigator, there being no uniform or common procedure. The results of this early work so clearly showed the need of systematism that the United States Department of Agriculture set experts to work out a reliable and uniform system of procedure. Dr. A. W. Morrill inaugurated our present system of marked tents and a system of dosage. which is known as "The Morrill System." This work was done in Florida. Later Mr. R. S. Woglum began operations in California and greatly perfected this system so as to make it at once practical and available to all the orchardists. |