Paris green, London purple, and other arsenites above mentioned de stroy injurious insects without dan ger to the foliage, and there is no good reason for buying these or oth er patented preparations that cost more and do not do the work any better.
Whale-oil Soap. — For San Jose scale on dormant trees in winter use: whale-oil soap, 2 pounds; water, 1 gallon.
For scale or aphis in summer use: whale-oil soap, 1 pound; water, 5 to 7 gallons. This may be quickly dissolved by the use of hot water.
Kerosene Emulsion — Milk For mula. — Kerosene, 2 gallons; sour milk, 1 gallon. Agitate from 3 to .5 minutes with a pump. Add 15 or 20 times its amount of water, ac cording to the plants to be sprayed.
Crude Petroleum.—This may be used in place of kerosene when it can be readily obtained. A crude petroleum emulsion is used on the Pacific Coast as follows: whale-oil soap, 1 pounds; distillate petroleum, 5 gallons. Pre pare as for kerosene emulsion, and add 12 to 15 times as much water.
Kerosene and crude petroleum in a mechanical mixture of about 25 per cent of the oil is about as effective as pure oil and much less injurious to foliage. Sometimes, however, in jury results, and it is advisable to use the plain oil and water in winter, and the dilute kerosene emulsion in sum mer.
White Arsenic. — This is cheaper and of more uniform strength than Paris green. It may be used safely with Bordeaux mixture, or in connec tion with soda or lime, but it cannot be safely used alone.
Arsenite of Soda for Bordeaux Mix ture. — Sal-soda crystals, 4 pounds; water, 1 gallon. Mix and dissolve. Add 1 pound of white arsenic and boil until dissolved. Add water to replace what has boiled away so as to leave 1 gallon of arsenite of soda. This is stock solu tion. Use 1 pint of this stock solution with 50 gallons of Bordeaux mixture.
Arsenite of Lime.—White arsenite if used alone may be prepared as fol dows; sal-soda crystals, 1 pound; water, 1 gallon. Mix and dissolve. White arsenic, 1 pound. Add this and boil until dissolved. Fresh slaked lime, 2 pounds. Add this and boil 20 minutes. Add 2 gallons of water to make stock solution. Use 1 quart of this stock solution to 50 gallons of water.
Arsenite of Lead or Disperene.— This preparation is very useful against beetles and similar insects, which are hard to poison. It can be applied in large quantities without harm to foli age, and adheres to the foliage a long time. This has been used almost ex clusively by the Gypsy Moth Commis sion of Massachusetts, and is strongly recommended by them. It forms a whitish coating on foliage, so it is easy to see whether or not the ar senite has been sprayed and when it has been washed off by rain. For the potato bug it has been found a more effective insecticide than Paris green. It costs more than Paris green, but remains suspended longer in the wa ter, and hence can be applied more evenly and goes farther. The for mula is: arsenite of lead, 1 to 2 pounds; water, 50 gallons. It is ready for use as soon as the paste is mixed with the water.
Hellebore. — This poison is not so strong as Paris green and other ar senates, and loses its strength after being exposed to the air, hence it can be used to spray fruit a short time before ripening. It is in common use on currants, gooseberries, and other small fruits. It may be applied either dry or mixed with water. For a solu tion use fresh white hellebore, 1 ounce; water, 3 gallons. Apply when thoroughly mixed. This is for insects which chew, as turnip worms, goose berry worms, currant worms, and saw flies.
Lime, Sulphur, and Salt Wash. This mixture is commonly used on the Pacific Coast against the San Jose scale. The formula is: lime, 15 pounds; sulphur, 25 pounds; salt, 15 pounds. Water, sufficient to make 50 gallons after boiling.
This wash may be boiled in an iron kettle. Heat the water before adding the lime and sulphur. The sulphur must be thoroughly dissolved.
Pour the mixture through a strainer into the sprayer. The best results are obtained by applying this wash while warm. It must be applied only in the winter while the tree is dormant. This is used against the San Jose scale, apple and pear scab, and leaf curl.
Oregon Wash.—Same as lime, sul phur, and salt wash, but substitute blue vitriol for salt. Use in the same manner for the same purposes.