. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. THE CONTROL OF INJURIOUS INSECTS 387 tion 10 days or 2 weeks after the blossoms fall should be diluted to a sp. gr. of o^ account of the tenderness of the apple pedicels. The amount of spray liquid varies with the size of the tree. A thrifty 9- or lo-year-old tree on the average requires i3^^ gal. for the dormant spray and i gal. for each of the later sprays. A 30-year-old tree requires 5 gal. for the dormant spray and 4 gal. for each of the later sprays. In boiling Hme and sulph
. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. THE CONTROL OF INJURIOUS INSECTS 387 tion 10 days or 2 weeks after the blossoms fall should be diluted to a sp. gr. of o^ account of the tenderness of the apple pedicels. The amount of spray liquid varies with the size of the tree. A thrifty 9- or lo-year-old tree on the average requires i3^^ gal. for the dormant spray and i gal. for each of the later sprays. A 30-year-old tree requires 5 gal. for the dormant spray and 4 gal. for each of the later sprays. In boiling Hme and sulphur to- gether according to the formulae given above, two sulphides of cal- cium (CaS4 and CaSs) and the thio- sulphate of calcium (CaS203) are formed. These are soluble in water. If too much lime is used a sediment will form. Only the best stone lime should be employed, and the boiling should not be too prolonged as in- soluble compounds are formed. 3Ca(OH)2+ iiS = CaS4 + CaSs +CaS203 + 3H2O. When the hydrometer has the Baume graduation marks ranging from o to 36° the mixture for^^the San Jose scale (dormant stage) should test between ° and 5° Baume^ and for the summer spray- ing about 1° Baume (Fig. 250). The following table of dilutions of lime-sulphur has been calculated for both hydrometer graduations: Concentrated. Pig. 250.—Diagram of hydrometer in use. i, For concentrated solutions and graduated from to specific gravity, with surface of liquid indicated at a-b; 2, for diluted solu- tion and graduated from to specific gravity, with surface of liquid indicated at c-d. (After Corby.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lochhead, William, 1864- [from old catalog]. Philadelphia, P. Blakiston's son & co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
