. Class book of economic entomology [microform] : with special reference to the economic insects of the northern United States and Canada. Insect pests; Entomologie; Entomology; Insectes nuisibles, Lutte contre les; Insect pests; Insectes nuisibles. THE CONTROL OF INJUKIOUS INSECTS 387 lion 10 clays or 2 weeks after'the blossoms fall should be diluted lo a sp. gr. of on 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 i'4 gal. for the dormant spray and i gal for each of t
. Class book of economic entomology [microform] : with special reference to the economic insects of the northern United States and Canada. Insect pests; Entomologie; Entomology; Insectes nuisibles, Lutte contre les; Insect pests; Insectes nuisibles. THE CONTROL OF INJUKIOUS INSECTS 387 lion 10 clays or 2 weeks after'the blossoms fall should be diluted lo a sp. gr. of on 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 i'4 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 lime and sulphur to- gether according to the formulE given above, two sulphides of cal- cium (CaSi and CaSt) and the thio- sulphate of calcium (CaSjOj) 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 4-iiS = CaS,-|- CaSa -f CaSjOa + jHsO. 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 f 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: c«oc«ntT»t«g. Fig. iS».—Diagram of hydrometer in use. I. For concentrated solutions and graduated from to 132 specific gravity, with surface of liquid indicated at 2. for diluted solu- tion and graduated from 1,00 to i 10 specific gravity, with surface of licjuid 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 L
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectentomology, bookyear1
